JPH03500927A - infrared radiation detection - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention provides infrared radiation for detecting selected molecules of interest in a gaseous sample. Detection means and method.

The present invention ii, especially gas chromatography, liquid chromatography, CO, detection , applicable to the fields of total organic carbon analysis and total inorganic carbon analysis.

Conventional technology Combustion flames have long been used analytically as a source for spectroscopy. However, 2 spectroscopy The analytical application of combustion flames as a source of has been studied in great depth to date. , almost exclusively limited to the study of radiation emissions falling within the UV-visible region of the electromagnetic spectrum It has been.

U.S. Pat. No. 3,836,255 describes a spectroscopic measurement that monitors both radiation and absorption. Describes a substance analyzer.

In this analyzer, the fluid is cyclically heated and cooled, and the emission of radiation is of interest in the fluid. It is a property of a substance that can be used.

US Pat. No. 3,516,745 describes a method for observing gaseous gas emission.

Gas is contained in the chamber.

It is cyclically compressed and freely expanded. Changes in infrared radiation is correlated to the concentration of gas in the tank.

Vibration excites or energizes the gas contained in the chamber and emits sparks. emits.

Similar to U.S. Pat. No. 3,516,745, U.S. Pat. No. 3,749,495 Full description of the radiation analyzer.

The samples are then compressed and expanded periodically. The compressed gas is The collision of the particles causes them to become heated, thereby producing infrared radiation. compression And the comparison of the radiation of the expanded gas produces different radiation depending on the gas concentration.

A significant portion of the total radiation emitted by the combustion flame is located in the infrared region of the Despite the fact that 2 the use of this radiation for analytical purposes has been studied. It looks like there aren't any.

In terms of optical radiation, the energy radiated from a combustion flame is in the ultraviolet region of the spectrum. Extends from to far infrared region.

Of all the energy radiated by the flame, the ultraviolet and visible range of The radiation time is only about 0.4 s (Gaydon, A, G,: Ths 5 peetro*eopy of Flames: Chapmln and B a1l: London, 1974; 221-243). to this On the other hand, infrared radiation from a combustion flame accounts for about 20 inches of the total radiant energy. (Gaydon, A, G; Wolfhard, H ,G,;Flames,Their 5structure,Radiat ion and Teroperatnre, 4th edition, Chapman and Hall', London.

1979. pp. 238-259). Transparent flames, such as hydrogen/air flames, are visible. radiation can be ignored and much of the radiated energy is in the infrared radiation of the Enter the area. Despite these facts, analytical applications of infrared radiation from combustion flames has not been studied yet.

Despite the lack of analytical research, a large amount of work has been Infrared radiation from hot gases for the purpose of tracking jet aircraft and rockets for applications in It has been done about line radiation. Much of this work involves 1 normal combustion flames flying It is used as a model for exhaust gases from the body. Plyler r,　E,に;　J,　Res.

Nat, Bar, 5tand, 1948. 40. 113) is especially 1- We are studying the infrared rays emitted by Bunsen's flame at wavelengths up to 22 Pm. 1-5p In the wavelength range of m.

Plyler believes that the two bands are the result of infrared radiation from CO2 and H,O molecules. As a result, I found that there was a large effect (Plylsr, E, Ni,; J, Rea , Nat, Bar, 5tand, 1948°40.113). one van -1 and others are at 4.3 pm ( 23261:II+-”).

Research on the infrared radiation of carbon dioxide shows that CO2 emits strongly at 28 and 4.4 μm. This shows that (Gaydon.

A, G,, The 5pectroseopy of Flames, Ch apmanand Hall”, London, 1974.221-423 Ichiji). The longer wavelength band corresponds to the asymmetric stretching and contraction of the carbon dioxide molecule (Na k! Lrnoto, K,: Infrared 5pectraof Ino rganie and Coordination Compounds;J ohn Wiley; New York, 1963. 77 Hage).

The infrared rays observed from a typical combustion flame are denatured by atmospheric absorption. As a result of the overlap of these two emissions in CO, the position of the absorption band is is shifted slightly with respect to the radiation band, so only part of the radiation band undergoes atmospheric absorption. (Curcio, J, A,; Buttrey, D, V, E,; Appl , Opt, 1966, 5. 231). Observed bar at 4.4pm exclusively through the emission of carbon dioxide.

The true 4.3 It appears to shift from the pm CO8 emission. The beam observed from the flame at 28μm The z5 and 27μm water bands are separated by the Z7μm carbon dioxide band and the 27μm water band. This is the result of duplication. Other bands are observed over the wavelength range of 1-22 μm However, the bands at z7 and 4.3 μm are the two strongest emissions.

The amount of infrared radiation observed from a flame also depends on a number of other parameters. Of fire Research has shown that much of the energy is due to conduction and This shows that it is lost due to convection (Gaydon, A, G,; The 5pectroscopy of Flames; Chapman an dHall: London, 1974+, pages 221-243).

Additionally, we observe that turbulence reduces the amount of infrared radiation emitted (G aydon, A, G; Wolfhard, H, G, “Flame s, Their 5structure, Radiation andTem perature, 4th edition a, Chapmln and Hall: Lo ndon.

1979; 238-259 part). Self-absorption is another factor that reduces radiation. Tardechiru. Therefore, the size, shape and properties of the flame are determined by considering the amount of radiation emitted from the flame. This is the first important parameter.

Additionally, the area of observation within the flame is an important consideration. Spatially, infrared The radiation of line radiation is greatest in the outer cone and local gas, and in the inner cone region. (Gaydon, A. -G, ; The 5peetroseopy of Flames; Ch apman and Hall: London, 1974; 221~ 243 pages). Previous research has shown that about one-seventh of infrared radiation occurs in the inner cone region. This shows that the remaining 6/7 comes from the outer cone/hot gas layer. (Gaydon, A, G,; The 5 pectroacepy o f Flames; Chapman and Hall: London, 1974; pages 221-243). High temperature gaseous combustion products formed in the flame The cone of the outer calf is formed by the formation of the algae where they are cooled by atmospheric entrainment. It continues to radiate on the parent part of.

Finally, and most importantly from an analytical point of view, the infrared cape radiates from the flame. is a function of the number of CO2 and salt molecules present in the hot gas. Therefore, qualitative Both quantitative and quantitative analysis are possible.

Brief description of the drawing FIG. 1 schematically shows the apparatus used in Experiment 1 for non-dispersive studies.

FIG. 2 schematically shows the apparatus used for the wavelength selection study in Experiment 1.

Figure 3 schematically shows the optical system used in Fourier transform interferometer studies. .

FIG. 4 schematically shows a preamplifier for a Pb5e detector.

Figure 5. Signal profile as a function of time for injection of 50μ of toluene. is illustrated.

Figure 6 illustrates the peak height signal as a function of injection volume (μt) for toluene. are doing.

Figure 7 shows when pure ethanol is drawn into the flame.

Figure 3 illustrates the effect of viewing height above the burner on the signal.

Figure 8 shows the signal obtained per mole of carbon as a function of the number of carbon atoms in two molecules. It shows.

Figure 9 shows a liquid chromatograph using a 10% methanol/water mixture at 2 WLt/min. detector for the signal observed at 4.3 pm when pumped to the burner. The effect of the bias voltage is illustrated.

Figure 10 shows the signal observed when pure ethanol is drawn into a flame at steady state. Figure 3 illustrates the effect of chopping frequency on .

Figures 11.1-11.2 show hydrogen/air flames and acetate using a Pb5e detector. Infrared spectrum obtained by the system on a len/air flame.

Figures 12.1-12.2 show the system when Co and ethanol are introduced into the flame. The infrared radiation obtained by the system is kutor.

Figure 13 illustrates the signal observed in 4.3μ lightning as a function of the flow velocity of CO. .

Figure 14 shows 4 as a function of the volume of ethanol injected into the liquid chromatograph. ．． The signal obtained at 3 μm is illustrated.

Figure 15 shows a 50μ mixture of equal volumes of methanol, ethanol and propatool. This is a chromatogram obtained when t is eluted from a liquid chromatograph. elution The order was methanol, ethanol, propatool.

FIG. 16 schematically shows the apparatus used in Example 2.

Figures 17.1-17.3 schematically illustrate the burner assembly in Example 2. Shown below.

Figure 18 is a chromatogram of 5 μt of unleaded gasoline obtained at 10% 0V-101. be. The column temperature was held at 55°C for 4 minutes and then increased to 200°C over 7 minutes. It was.

Figure 19 shows the elution peaks obtained for two different volumes (μt) of methane. . Column temperature: 90°C.

FIG. 20 illustrates peak height versus volume (μt) for dichloromethane.

Figure 21 shows peak height versus volume (μm) for trichlorotrifluoroethane. 1 is shown.

FIG. 22 illustrates peak height versus capacity (μtuft) for carbon tetrachloride.

FIG. 23 illustrates peak height versus volume (pt) for carbon dioxide.

Figure 24 shows 1. Carbon dioxide: 2. Pentane: 3. LL2-trichloro-L2. 2-) Lifluoroethane; 4° dichloromethane; 5. Flame red regarding carbon tetrachloride Illustrating peak height versus injected compound (μmol) obtained by external radiation detector ing.

Figure 25 shows the logarithm of the peak height for pentane versus the logarithm of the injection temperature i:(pt). Illustrated.

Figure 26 shows flame infrared radiation detectors for methane, carbon oxide and carbon dioxide. It illustrates the relative response. Figure 27 shows various compounds containing different numbers of carbons, namely BR-ETJ -L; DI -CL, dichloromethane; TRI-CL, trichloromethane: TRI-CLEN,) Ricoroeta/　-,v;TETRA-CL carbon tetrachloride; TRI-CL-F,) dichlorotrifluoroethane: N-PENT, n-penta N;N-HEX.

n-hexane", N-HEPT, n-heptane; C-PENT.

Cyclopentane; C-HEX, cyclohexane: c-HPPT, cyclohepta y; C-M-HEX, methicyclohexane; C-0CT, related to cyclooctane do.

Figure 2 illustrates the relative response of a flame infrared radiation detector per mole of carbon.

Figure 28 shows the peak height versus carrier gas flow rate obtained using a flame infrared radiation detector. Illustrated.

Figure 29 shows the peak area versus carrier gas flow rate obtained by a flame infrared radiation detector. It shows.

Figure 30 shows methane (1); 1. L,2-trichloro-1,λ2-trifluoro 1:2:1:3 (by volume) mixture of loethane (2): hexane (3); carbon tetrachloride was obtained isothermally at 50 °C for the Apiezon-L column for injection. A chromatogram is shown.

Figure 31 shows the experimental equipment for experiment 3, including the burner, mirror, and Fourier transform interferometer. Shown schematically.

Figure 32 shows that the flame infrared radiation of carbon tetrachloride is emitted by a coutor.

FIG. 33 is a methanesulfonyl fluoride flame infrared emission bottle.

Figure 34 shows that the flame infrared radiation of I(2/air pack ground) at high gain is It is Kutle.

Figure 35 shows the flame infrared radiation of methanol.

Figure 36 D shows the flame infrared radiation spectrum of trichlorotrifluoroethane.

FIG. 37 is a flame infrared radiation spectrum of tetramethylsilane.

Figure 38 schematically shows an arrangement for a combined infrared and flame ionization detector. vinegar.

Summary of the invention The present invention relates to means and methods for detecting infrared radiation, thereby detecting infrared radiation of interest in a V sample. The present invention uses the infrared radiation of excited molecules as a basis for the detection of compounds. In one embodiment of the present invention, infrared radiation is used as a means of detecting chromatographic waste. observed. The organic compound introduced into the flame has a wavelength of 2 to 5 μm. This results in the production of carbon dioxide, which causes a strong radiation band to be observed.

Measurement of both total organic carbon (TOC) and total inorganic carbon (TIC) in water-containing samples Can be done. Total inorganic carbon and total organic carbon are important analytical sources for the environmental characterization of water. are the parameters of Measurement of total organic carbon is a measure of organic matter in water in pollution monitors. It is usually used as a non-specific guide to the content. Inorganic carbon is bicarbonate and charcoal in water. Exists as acid ions and as dissolved carbon dioxide. Total of these carbon substances is called total inorganic carbon (TIC).

TIC generally involves acidifying the sample and dissolving bicarbonate and carbonate ions in CO2. the sample was purged with gas to remove dissolved COl, and the sample was converted to (usually by infrared absorption!7). flame infrared radiation Measuring total inorganic carbon by detection, measuring the amount of inorganic carbonate present in a water sample It can be used instead of alkaline titration.

Infrared radiation detection monitors carbon impurities in electronics-grade gases It can be used to Carbon/hydrogen characterization of compounds by infrared radiation detection Signs can be detected by detecting two strong radiation bands, one of which is a diacid. Some relate to carbon dioxide, others to both water and carbon dioxide. Heteroatoms are It can be observed using 3-layer transform infrared emission spectroscopy. Many biochemical reactions produce byproducts. Infrared radiation detection is used in a variety of clinical and biochemical applications, resulting in the release of carbon dioxide. can provide the basis for the analysis of

The flame ionization detector (FID) is probably the most recently used GC detector. Ru. It is certainly most sensitive for organic compounds. FID and flame infrared radiation A combination infrared detector combined with a radiation detector has FID sensitivity and lacks FID (CO , Co, and other compounds as indicated by flame infrared radiation detection and flame infrared radiation. Provides excellent quantification of elementary moles.

Detailed description of the invention The present invention provides infrared detection for detecting selected molecules of interest in gaseous samples. Relating to means and methods. The infrared detection means has an infrared radiation characteristic as well as the detector means. means for exciting the molecules of interest in the sample to emit a radiation pattern including. In one embodiment, heating, preferably with a flame, vibrationally excited molecules that can be used to excite molecules and emit infrared radiation produced carbon dioxide. Calculate the infrared radiation emitted by the molecule of interest. wavelengths observed by generating electrical signals in response to radiation at the observed wavelengths. Ru. The observation wavelength is preselected from the characteristic infrared radiation pattern of the molecule of interest. It will be done. The means for isolating a preselected wavelength of infrared radiation comprises an excitation means and a detector hand. Provided between the steps.

The factors necessary for the successful implementation of IR radiation are the The aim is to achieve a useful level of contrast, i.e. the source is surrounded by packed graphics. the source temperature must be greater than the detector temperature. I have to go. For this reason, if the packground and detector are If the temperature is room temperature, we cannot expect to see infrared radiation from a gas at room temperature. Dew. Therefore, the first requirement for the successful implementation of this technology is often gas It is a means of heating above room temperature. This doesn't necessarily mean you need a flame do not have. However, the higher the temperature of the gas, the higher the emissivity of the 2 divergence. The detection system becomes more sensitive. The flame is generally on the order of 2000-3000° Since they have a temperature of If a ground flame can be found, it represents a potentially good radiation source for this application. That will happen.

However, other means can be used to excite a blackbody to emit a band of infrared radiation. Emphasis should be placed on what can be done. If other means are used, the sample is CO! It would have to be oxidized to detect the emission band.

Other non-thermal excitation means include (1) by electron mIF in a gas discharge; excitation of carbon dioxide, (2) by collision of a second object with vibrationally excited nitrogen; Excitation of carbon dioxide (similar to the mechanism used in carbon dioxide lasers) , and (3) optical excitation by a suitable source. Photoexcitation, even at room temperature, is Achieved by existing 010 level (non-resonant excitation) or 000 level (resonant excitation) can. Such infrared fluorescence is a diacid that emits radiation at 10.6F72M. It is conveniently excited by a carbon laser.

Such radiation would cause a transition from 010 to 001.

The second requirement regarding high sensitivity is that any shape of solid container such as a sample cell The purpose is to avoid using it. To know the infrared radiation, as a result of the thermal gradient The contrast between the infrared radiation source (i.e. gas in this case) and the pack ground is There must be a strike. However, when a heated gas is introduced into a solid sample container, When you can

The body immediately begins to heat the container and the thermal gradient and contrast It gradually disappears over time as thermal equilibrium is reached. As a result of this process, it The radiation signal initially present from the gas because it is hotter than the walls of the recess will be First, it disappears into the puck ground.

As a result of this phenomenon, experiments to date have shown that hot gas and cooled gas can cause the system to heat up. at a sufficiently fast rate that it does not have time to reach equilibrium (i.e. use of thermal cycling). A complex recirculation system must be used to alternately enter the sample cell. There wasn't. If a sample container is not used, such as by flame, radiant gas There is no blackbody radiator heating up the surroundings, and no steady-state radiation signal can be observed. Ru. This radiation signal exists as long as the sample is introduced into the flame, and the pack graph does not collapse over time like in previous systems where the . For this reason, thermal cycling is not necessary in the present invention.

The use of high temperature sample cells also reduces atmospheric absorption by atmospheric carbon dioxide (i.e. C O, is effective in reducing the effect of tail/L absorption when observing radiation. Ruru. As the gas is heated, two different upper level vibrational states exist. and a transition between the upper levels occurs. Therefore, the observation for hot gases radial band range, resulting from upper level vibrational transitions (e.g. v = 4 to v; 3) component, and therefore tends to broaden somewhat to longer wavelengths as temperature increases. and shift. In contrast, carbon dioxalinate at room temperature is primarily at the lowest vibrational level. (V=O). Since the emission band shifts with respect to the absorption band (emission The radiator is hotter than the absorber.

Atmospheric absorption of carbon dioxide is not a major problem.

Finally, when Co radiation is observed in the flame, the flame is selected and itself diacid shall not produce or contain carbon dioxide. This eliminates the use of all carbon-containing fuels. and suggests the use of hydrogen-fueled flames. Two possibilities: hydrogen/air flame and hydrogen/oxygen flame exist. Of the two, hydrogen/air flame is more convenient. It is. it is.

It makes it easy to design burners without flame backflow (i.e. explosion). This is because it has a high burning rate.

A hydrogen/oxygen flame produces a large signal due to its high temperature. carbon dioxide release One of the radiation bands is shown in the hydrogen/air flame (producing a composite band at Z7μm). overlaps with the two water radiation bands, but only other carbon dioxide radiation occurs 4,3 μm area is free of any other potentially interfering flame packground . For these reasons, a preliminary study of hydrogen/air 2 flame infrared Co, radiation Therefore, it was selected as a sample cell.

Compared to other sources, the combustion process involving hydrocarbons mainly produces CO, C ot and to produce water vapor.

Particularly useful for detecting organic compounds. Their proximity to combustion processes (which are exothermic) Because of the contact, the generated molecules are in a highly excited state regarding vibrational and rotational transitions. be.

Therefore, the carbon dioxide radiation obtained from the flame of combustion containing hydrocarbons is It actually produces more strength than an equivalent amount of carbon dioxide at the same temperature produced from an oven. The sensitivity of many detectors in the infrared is also sensitive in the UV/visible. However, they are quite sharp compared to other available detectors such as photomultiplier tubes. Because they are not sensitive.

Generally not used in this area. Photomultiplier tubes are based on external photoelectron effects; Photons absorbed by a suitable light-emitting material are emitted from the material into the surrounding vacuum. Ru. To give the electrons enough energy to exit the surface of the photoemitter, e , the collected photon is the sum of the energy bandgap and electron affinity of the photoelectron emitter. Must have more energy. of electrons as a result of the photoelectron effect. Detectors based on photoemission are highly efficient due to the use of electron multiplication by dynode chains. I can do it sharply. Therefore.

Photomultiplier tubes can be so sensitive that they occur within the detector itself. Rather than fluctuations, they are often limited by fluctuations in the arrival speed of photons. Unfortunately Therefore, the energy requirement for external photoemission is large enough to The use of multipliers is primarily limited to the UV/visible region of the spectrum. consisting of photoelectrons By reducing the electron affinity of the emitter, wavelengths longer than the visible (approximately 950 Photomultiplier tubes corresponding to wavelengths other than nm have been manufactured.

Infrared equivalent detectors can be divided into two basic categories. heat detector and quantum detectors. Heat detector.

This corresponds to the heating effect of infrared radiation and includes thermocouples, thermistors and piezoelectric detectors. nothing. Quantum detectors make use of the internal photoelectron effect, whereby simulators are removed from the valence band. It passes into the conduction band but is not ejected from the material. As a result, these detectors energy responds to wavelengths corresponding to the semiconductor bandgap. These detectors , including photovoltaic detectors and photoconductive detectors. Any of the above detector category IJ- It does not use any form of internal amplification similar to a photomultiplier, so the rR detector / Less sensitive than the detectors commonly used to detect visible radiation. These detectors The main sources of noise occur within the detector itself and in the radiation field. These detectors often reduce detector noise because they are not due to fluctuations in Spectrometers that are cooled and use them to reduce detector noise limiting It is called do.

Among the various infrared detectors available, child detectors are generally more expensive than thermal detectors. However, thermal detectors have a flat response over a wide wavelength range. It has the advantage of For the application being considered, the temperature of dry ice or liquid nitrogen It was desired to have a detector that did not require cooling. Wavelength range under consideration (2-5pm ), lead selenide and indium antimonide detectors are two possibilities. It was. Among the two, indium antimonide had a higher detection rate, but one Generally required cooling.

For this reason, Pb5e detectors are was selected as the most appropriate for preliminary research. However, even if Pb5 Even with e-detectors, a certain degree of thermoelectric cooling maximizes the detector's response to long wavelengths. It would be advantageous to shift.

carbon dioxide without interference from other radiation bands (e.g. those in '2-7 μm). To detect 4.3 μm radiation/; Isolation was required. The radiation processing t# of conventional grating monochromators is relatively small. These systems are not completely satisfied in the infrared region because of the Therefore, the Fourier transform method is preferred. However, due to the single molecule response the filter A bandpass filter is selected that transmits the desired band. Ta. In this way, the desired band can be detected without reducing the radiation throughput to the detector. isolated.

The superiority of radiometric measurements over e-collection measurements in the visible region of vectors is 2 minutes. This is well known among optics.

In retrospect, no one thought to take advantage of this advantage in infrared light. That's surprising. The reason, no doubt, is intuition, but radiation is a collection of excited states. In contrast, since absorption uses a collection of ground states, radiation There is a completely erroneous idea prevalent among chemists that radiation is less sensitive than absorption. . In all humans, the ground state is more abundant than any excited state, so absorption must be more sensitive than radiation.

The big flaw in this argument is the fact that it is irrelevant.

In fact, the reason why absorption measurements are less sensitive than corresponding radiation experiments is because the detection limit As the ratio of incident beam intensity to transmitted beam intensity approaches Due to the fact that it approaches. This means that the transmitted beam intensity is smaller than the incident beam intensity. It means approaching the size. During the detection of these two large numbers There is a great deal of controversy surrounding whether it is statistically possible to tell the difference between The difference between two large numbers that are similar in size and fluctuate is often not significant. However, it is well known from statistics. In contrast, with radiation, the signal is removed from the background. Limits of detection occur when they are statistically indistinguishable. The background is preferably This situation is small.

Additionally, radiometric measurements equal to the difference between two small numbers are statistically even more reliable. is usually linear over a very wide range of concentrations. Therefore, it is better than e-yield measurement. The use of filtration radiometry is for valid analytical reasons.

It's not just another way of accomplishing the same thing.

If a flame is used to burn the sample and convert it to carbon dioxide, this It is worth pointing out that carbon oxides do not seem to be able to be monitored by absorption measurements. It's a benefit. Also, the reason is based on the understanding of Kirchhoff's laws.

If the carbon dioxide produced by the flame is monitored by absorption measurements, the flame A blackbody radiation source with a temperature higher than that of the gas would be required. The temperature of the flame is approximately 2300° Therefore, it is at least extremely unlikely to find a solid blackbody source hotter than a flame. It should be said.

The processing gas is the gas used during manufacturing and the electro-ex gray. This is the gas used in particular in the manufacture of the Electro-X device. semiconductor Impurities in the bodies used in the production of body devices, such as CO1COt and traces of carbonization. Hydrogen must be controlled to ensure reliable production conditions . Concentrations of impurities of about 0.5-1 ppmv in nitrogen and argon create difficulties. (Whitlock, W, H.

et al., Microcontamination, May 1988). recently.

The above impurities can be measured using flame ionization using a device based on gas chromatography. This is done by using a detector (FID). FID is CO or Co Therefore, catalyst systems using nickel as 8s convert CO and CO2 into methane. It must be used to convert to Catalytic methanator and? JM pulp type This need makes modern technology less than ideal.

In contrast, infrared radiation detectors detect CO, Co, and light gaseous hydrocarbons. It has good sensitivity. Methanation catalyst as no catalytic methanator is required and do not encounter problems due to complex valve systems. Moreover, continuous monitoring technology This is possible with line radiation systems. In such systems, three types of gas flow simultaneously can be analyzed.

One stream is fed directly to the flame. This flow is based on the total impurity concentration (i.e. co, co , and hydrocarbons) (Sl). The second step is to first carry out the second infrared radiation inspection. It passes through a bed of Co absorbent before entering the extractor. This stream contains CO- and hydrocarbons ( Sz). The third flow first enters the third infrared radiation detector. Co, passing through a bed of absorbent (A+5carite). This flow is composed of CO and carbonized Measure the total hydrogen (S3). The signal from the third stream is filtered by impurities as shown below. Concerning the concentration of

S*+Ss S1=hydrocarbon St-s3=co.

sl-s, = c.

By measuring a combination of components simultaneously, an infrared radiation system It has multiple advantages over systems that measure minutes one at a time.

Another major application of infrared radiation technology is in water analysis.

This is a drinking water (potable water) environmental sample.

It even includes clay-based muds used in wastewater and petroleum production (ie, oilfield equipment).

This application falls into two main categories. Determination of total inorganic carbonates and organic carbon.

The presence of carbonates in water and other fluids has a detrimental effect on the use of these fluids. has. For example, the presence of dissolved carbonates along with dissolved calcium can and causing scale to form in industrial piping systems. Scaling in piping systems The formation of a wall not only obstructs fluid flow but is also used for cooling purposes. decreases the heat transfer efficiency of the fluid. In oil production, the presence of carbonates is detrimental to the performance of clay-based muds (Garrett, R.L., J. , Pet, Teeh, June 1978; 860 pages).

) In modern water technology practice, carbonate concentrations are determined indirectly by alkalinity titration. I can't stand it. What is the alkalinity of the water sample?

CB “h=[A1k]=(HCOs-’)+2(COs”-)+( OH’″)-[:H”)[:A1k]=αICT+2αtC-r+(OH −]CH”] (where cA = concentration of strong acid cB = concentration of strong base C7 = [Hz COs] + CHCo5-) + (COs"-) D = ( (H”:l” + Ki (H”) + KI K Goose) α5=Kt (H”)/D a goose = KIK, /D And 1 and 2! are the first and second order dissociation constants of carbonic acid) This can be determined from the proton conditions of the solution. The alkalinity of a water sample is also a solution This is a measure of the acid neutralizing power of

Titrating a sample of water to the endpoint of methyl orange by strong & (H,5O4) gives the total alkalinity of a water sample. Total inorganic carbonate or C,r is By rearranging the relationship between alkalinity, we can understand the knowledge of alkalinity.

CT=((:Alk:l　(OH-)+[H”))/(’t+2ff goose)CT~ [Alk]/(al+2at) Therefore, unless there are other alkaline materials in the water besides carbonate, the alkalinity of the solution and pHFi are all necessary to establish CT. However, measurements consisting of e.g. In the mud, significant amounts of other alkaline materials are present, which makes FiCT This makes alkalinity titration data unreliable. Even if other interference Even if you don't have anything.

Titration of alkalinity is difficult to perform because the end point of the indicator is not sharp. and Even when a potentiometric titration is performed, the sample is being back-titrated to carbonic acid. It's not sharp.

In contrast, infrared radiation TIC measurements are simple, convenient and straightforward. direct Because of this, infrared radiation directly affects cT rather than CT-related properties (i.e., acid neutralizing power). means to measure. The use of direct measurement techniques makes it possible to determine the actual parameters of interest. leading to more reliable data regarding For direct measurement, the desired (Knowledge of the dissociation constant for carbonic acid is not required to calculate the ramometer.

In the infrared radiation method, a sample of water (2-) is placed in a 7-litre sp/(- ring tube). where it is then conjugated with sulfuric acid (0,5-) to carbon dioxide gas. It is flashed with helium into a hydrogen/air flame. diacid Infrared radiation from carbonized carbon is measured by an infrared radiation detector as described above. . A calibration curve made from standard carbonate solutions calculates the total inorganic concentration in the sample. used for.

Infrared radiation detection also detects carbon dioxide in carbonated beverages such as Noato drinks and beer. It is useful for determining the content of

Organic materials in water samples are derived from naturally occurring compounds produced by living organisms. or arise from a source of human modification.

The sum of naturally occurring and synthetic organic materials is the total organic carbon in the water sample. It can be considered as Therefore, the total aryu carbon content of the sample is is a non-specific (i.e. does not measure the actual individual compounds present) measure of whole organic Carbon (TOC) measurement can be carried out in groundwater, drinking water, semiconductor processing water, civil wastewater and industrial wastewater. conducted on a wide range of samples including industrial wastewater (Small, R, A.

et al., International Laboratory, 1986, May. ).

Industrial applications of TOC measurements include mineral products such as acids.

Organic inclusions in alkaline solutions and chlorides of aluminum, nickel and cobalt including measurements of Electric power generation plants use TOC measurements to measure cooling water and steam generation. Measuring organic contaminants in raw water. Even small amounts of formic acid and acetic acid can damage turbine blades and Causes corrosion of heat exchange equipment (Bernard, B, B, , [A Su mtnary of TOCDevelop-mentl! lJ, O, 1, Co rpor&tion CoCo11e 5tation.

Tex&s, 1985). Since an increase in the organic content of water is an indicator of pollution, T OC measurements are used in surface water, groundwater, mixed wastewater and industrial effluents. (i.e., wells) and other water sources.

Recently, TOC measurements have been performed by first oxidizing organic materials to carbon dicarbonate by two different methods. (Small.

89 people, International Laboratory, 1986゜ May). The carbon dioxide gas produced by this oxidation is secondary to non-dispersive infrared radiation (NDI). R) Determined by absorption spectrophotometry. Various NDIR methods have been used, but absorption The main problem with measurements is the co-absorption of water vapor and acid gases. steam drying Partial elimination of interference is achieved by controlling the humidity of the reactant gases flowing into the infrared absorption cell. This has been achieved by Measurements are made in absorption, so all TOC analyzers use infrared Requires an infrared radiation source to produce line radiation.

Carbon dioxide has recently been used in infrared systems to oxidize organic materials to CO-. generated by the same method that can be used. These oxidation methods include one of the following methods or Including combinations. Chemical methods e.g. use of peroxydisulfate, heating e.g. The use of oxidized steel and heating in furnaces and UV radiation. After oxidation, CO, is removed from the sample in the infrared is flashed to a radiation detector.

On the other hand, if an infrared radiation detector is used to excite molecules of interest in the sample, If a flame is used, the sample is combusted directly in the flame to generate CO, . C.O.

By using infrared radiation instead of absorption of Interference by existing objects can be avoided.

Infrared radiation detectors are unaffected by water vapor and acid gases, so these interferences are Not present in infrared emission TOC analyzers. Infrared radiation systems use filters. Since the Enter category.

Two strong radiation bands were observed in the flame, one corresponding to the asymmetric stretching vibration of carbon dioxide. and the other corresponds to the combined band of water and carbon dioxide, so the carbon of the compound /hydrogen characterization is possible by using both bands. any organic material Upon complete combustion of the material, both carbon dioxide and water vapor are produced. These compounds The presence of both the 4.4 pm carbon dioxide band plus the 2-9 μm water band change the strength of the command. Therefore, a chromatograph that monitors both of these bands is Raffi infrared radiation detector is available as FID or thermal conductivity detector Provide additional information about the compound beyond. This system is a traditional combustion analysis cannot calculate the carbon/hydrogen ratio with the same accuracy as the Distinguish between lukenes, aromatics, etc. Carbon-to-hydrogen ratio devices are used in chimneys and rocket engines. such as in an ignition monitor.

Useful for combustion monitoring.

Infrared radiation is useful as a detector in conventional carbon/hydrogen analysis (chroma Although I am opposed to its use as a detector in topography). TOC Infrared radiation systems can be used as a detection means in analysis, as well as in analysis. It will be done. Therefore, the on-board carbon hydrogen analyzer converts organic materials into water and carbon dioxide. Conventional combustion tube technology is used to replace the Infrared radiation Fi2 This occurred next. It is used to detect the amount of other materials.

When an organic compound containing a petro atom is introduced into a hydrogen/air flame, various other emissions occur. Emits a shooting band. Fluorine and chlorine-containing compounds exhibit the characteristic emissions of Hct and HF. generate vectors. Silicon and sulfur-containing compounds have 5t-0 vibrations and SOt vibrations. generates a radiation characteristic of Freon 114 includes HF, HCl, Co, H, O and A very interesting radiation spectrum with a large number of other bands attributed to C-F vibrations is Generate torque.

Many biochemical reactions release carbon dioxide as a byproduct of reactions (e.g. yeast fermentation of sugar). It walks external radiation, a clinical measurement of carbon dioxide in the blood It is useful in many clinical and biochemical analyzes involving carbon dioxide, such as carbon dioxide.

experiment The experimental aspects described below are exemplary.

Experiment 1 Figure 1 shows the experiments used for the first nondispersion study using thermistor detection. Indicates the target location. Neb Varian Techtron Burner Assembly 10 It was used as a riser and equipped with a sample introduction system. has a diameter of 1.5o Design the Meker burner head that produces flame 11 and assemble the burner Attached to Bree. The first study of infrared radiation from a hydrogen/air flame 11 The seed located in the detector head/housing unit on the test equipment facing the Thermoflake thermistor 12 (Thermonetries In c, Edjson, NJ). of these nondispersion studies. In order to limit field. Thermistors 12 and 13 are.

Wh　ea　t　st　n　n　e bridge circuit, Model 31 20 TXBaseom Turner digital data acquisition unit (Base omTurner rnstrunent, a, Norwootl, MA ) was used to record the output. The introduction of the sample begins with a cap to receive the septum. A Teflon injection device 14 consisting of a T-coupler with one channel connected to achieved. The Teflon injection unit 14 described above is used in this test equipment. .

Study the direct injection of organic compounds into the flame 11 and samples from the chromatograph We simulated the introduction of Using this arrangement, samples up to 5 opt It was possible to inject using an Ilton micro syringe.

Figure 2 shows the experimental setup used in the dispersive wavelength selection study using the Pb5e detector 24. shows. The IR detection systems used in this study were of various types as listed in Table 1. Assembled using equipment from manufacturers.

Table 1 Equipment used Burner Varian Teehtron burner/nebulizer, Mek With er burner head Dispersion system Bausch and 150 grooves per 1fi burning 4μm Sp@xModel 1870 0.5yr+Czer with Lomb lattice ny-Turner monochromator Population slit width 3-2 height 3α Detector Han+am4tsu Model Pb5e Model P2038 -01 Pr1neet with amplifier PAR Model 125A variable speed chopper on Applied ResearchModel 128 A Lock I Varian Aerograph Chart Recorder Flow meter Brooks Instrument Division comparison positive flow meter Chromatograph Varian Model 15000HPL with MCH-5 column C. 3pex α5 yn Czerny-Turner monochromator (Spe Industries, Ine, Metuchen, NJ) Used as a wavelength dispersion device or isolation means. A monochromator burns 4 μm. Each mackerel abutment is equipped with a grid of 9,150 grooves. A 3-inch inlet slit was used. 5pex The wavelength scale of the 1870 monochromator is about 1200 grooves/grooves. calibrated by the manufacturer. The wavelength setting is determined by a grating of 150 grooves/ri. Measurements were made of the rotation of the grating versus the counter settings. mirror geometry and Combined, these measurements measure the wavelength of the grating corresponding to the given counter setting. formula %formula%) (However, 1m is the order, τ is the wavelength, dij lattice constant, rid rating Calculation was made possible by calculating the rotation angle of the child. In this equation, θ snow is the collimator - is the angle of reflection of the main ray from the steel and 04 is the angle of incidence of the main ray on the focal steel. be. For a given optical layout, the θ2 and θtFi constants are used. these The calculation was performed by observing the 670.7 nm line from the tertiary lithium hollow cathode. By comparing the counter settings observed during the trial and the counter settings near the dormitory, was checked.

HamamlLtsu lead-selenide photoconductive cell with P+ electric cooling (P2O3 8-01, Harnamatsu Corp, San Jose.

CA) was used as an infrared detector. Table ■ Lists the details of this special equipment. ing.

Table ■ P 2038-01 Harnamatsn Pb5e detector rating Photosensitive size = 1 x 3 brocade Peak response height: 3.8μm IR cutoff wavelength: 4.85μm Dark resistance: Q, 6M ohm Recommended load resistance: 0.5M ohm Detection rate (source at 500, 600Hz chopping frequency, IHz non-stop width): 1.2 X 10”tMHz”!F’Housing/Mounting Assembly The detector 24 in FIG. The lens was configured to be installed at the focal plane of the monocucometer together with the lens. 30 ．． A power supply adjusted to 0 volts was initially used as the power supply for the detector 24. B　lFE The circuit of a preamplifier consisting of a TFET operation amplifier and 46 components is shown in Figure 4. is shown. The amplified signal from the preamplifier is sent to the Pr1nston Appli ed Re5eareh Mode 1128 person lock-in increase width a (Pr1nc eton Appiied Research, Pr1nceton, NJ ) (not shown). The radiation from the flame has a chopping frequency of 86Hz. Number Pr1neeton Applied Re5eareb Model 1 25 A speed chopper (Pr1neeton Applied Re5ear Ch.

Pr1neeton, NJ). Output from lock-in amplifier Power to the Varian Aerograph strip chart recorder displayed. The Pb5e detector 24 uses a monochromator. It was used in this research.

Wavelength selection studies were also performed to isolate the 4.3 pm emission band of Pb in Figure 2. This was done with a high pass filter in conjunction with the 5e detector 24. In this embodiment, 15p A high-pass filter (Corion Carp) with a short wavelength cutoff of m.

Holliston, MA) is installed in the housing in front of the Pb5e detector 24. Ta. Since the long wavelength response of the detector 24 is only extended by about 5 pm, This arrangement effectively isolates the 463 μm band without the need for a monochromator.

Varian Techtr on burner assembly used for non-dispersion studies -20 (Varian Instruments, Pa1o Alto.

CA) is also used as a sample introduction system in dispersion studies. Moxibustion The shield is constructed of stainless steel plate and is designed to minimize the effects of drafts on flames. Mounted on burner assembly to lower. Combustion to burner 20 and other gas flows using Brooks Instrument gauges and flow meters. (Brooks Instrument Division, Emers on Electric Co., Hatfleld.

PA) was used as a control. Three fuel/oxidizer mixtures were used in this study. Ru. Hydrogen/air, acetylene/air and hydrogen 720% oxygen/80 thiargon.

The liquid chromatograph used in this study was a Var ian Model 5000 (VILrian Instruments, Pa1o Alto, CA). Modelsooo and Varia The interface of the burner assembly 20 is initially made of zero volume stainless steel. With a similar diameter to the stainless steel outlet tube of the MCH-5 column by coupler This was accomplished by simply installing polycarbonate tubing. First experiment and test After that, a Teflon tape coupler 26 was added. This is before suction by burner 2o. Other solvents were then mixed with the chromatography eluent. The purpose of Cubsea 26 is burner/neb by mixing water and chromatography eluent before atomization. The purpose of the riser 20 is to improve sample aspiration. On the other hand, the same device , direct introduction of column eluent into burner 20 without prior mixing with water if desired I did it. All reported chromatographic results are based on T-coupler 26. It can be obtained using

Methanol and water are used as solvents for all chromatography experiments. Mail Tanol is T (PLO grade and water is triple deionized. All standards Compounds are reagent grade.

In chromatography, various types of methanol and water are used along with pure water as the eluent. It was carried out using a mixture of

Injection loops of either 10 or 50 pt capacity were used for all experiments. sun A pull is prepared from a mixture of pure compounds and sampled using a single syringe. Added to the pull loop. Samples are introduced onto the column using a conventional rotary valve. I entered. All experiments were performed using a T-coupler prior to suction by burner assembly 20. -26 using water as the make-up solvent 27.

The first non-conventional study aimed at exploiting the advantages of monitoring infrared radiation from combustion flames. Dispersion studies were performed using a thermistor detector. used in this study Flake thermistors are Pultley (Pultley, E, H.

In　ptical　and　Infrared　Deteetors,　K eyes.

R-J, ed.; Springer-Verlag: Berlin, 1980° It falls into the category of heat detectors described by Chapter 3).

and keeping the actual detector mass as low as possible, resulting in faster response times. (75 ms), and by keeping the thermal capacity of the detector low, the relative responsivity is configured to increase the

Flafther misters are more sensitive than their non-flake counterparts, but are less sensitive to flames. When the radiation is dispersed by a 0.5 m monochromator (IC), the existing infrared radiation It was found that it was not sensitive enough to detect the level of energy.

This lack of response in a dispersive manner is due, at least in part, to the o, sm monochrome due to the relatively high dispersion obtained with the chromometer. However, the state of non-dispersion (i.e. in a thermistor placed approximately 30 tysO from the flame). These detectors emit from the flame as a result of the introduction of an amount of carbon-containing compounds into the flame. Changes in infrared energy can be easily monitored.

In the preferred embodiment shown in FIG. 3, the eluent from the chromatograph is analyzed by Rie transform interference. The burner/nebulizer 30 is a liquid chromatograph The graph eluent is used to evaporate and excite the sample.

Burner assembly 30 may be the burner described above with respect to FIG. The burner assembly shown in FIGS. 16 and 17, discussed in detail below with respect to Either Lee. The infrared radiation emitted after the sample is introduced into the flame is through three mirror assemblies 32, whereby the amplifier and and an infrared detector. lens 39 and interferometer 34 The distance between them is about 10c1j! It is. The output of the interferometer 34 is sent to the computer 38. connected to analyze the collected data using fast Fourier transform to extract the sample and its Obtain the structural response of the molecule of interest contained within.

Using the apparatus shown in Figure 1, samples were prepared as previously described (BuI!ch, K, W: Rowell, N, G; Morrison.

G, H,; Anal, Chem, 1974.46.1231) Hydrogen/air was introduced into the flame by injection using a sample injection device. Figure 5 shows the The signal profile obtained as a function of time for injection of 50μ of luene is shown.

Figure 6 is a plot of signal (i.e. peak height) as a function of injection volume (pt). shows. Similar plots were obtained for injections of two different volumes of methanol.

These results indicate that the red color from a hydrogen/air flame is a result of the combustion of small amounts of organic compounds. This suggests that external radiation can be observed.

The results also show that the observed radiation is a function of the amount of sample introduced into the flame. It is confirmed. Next, a series of studies investigated the effects of various flames on the observed infrared radiation. / This was done to improve the effect of Mirameter. Figure 7 shows pure ethanol in a flame. The effect of the observed height of the flame on the signal obtained when drawn into the flame is shown. these The result Vi, obtained non-dispersively by a thermistor detector 25 cln from the flame. It was. To limit the field of view seen by the detector.

A stainless steel tube with a length of 10cy* and a diameter of 1゜2cIR is used as the detector housing. Install. Using this arrangement, the maximum radiation is at the tip of the visible part of the secondary combustion zone. It was found that this occurs at high levels. The study of fuel-to-oxidizer ratio with this system reveals that the stoichiometry of the flame has less effect on the signal than the observed height of the flame. did. Over the range of available flame stoichiometry, the largest signal is at the tip of the flame tip. always observe the degree, and seem to be very unaffected by the stoichiometry of the flame. A fuel to oxidant ratio of only 0.653 was used in all subsequent studies. That's Dora Gives a flame of a convenient size (i.e. not too high) that is not very affected by the Takara deru. A stoichiometric hydrogen/air flame is compatible with a fuel-to-oxidizer ratio of 0.4. As such, the flames used in these studies were somewhat fuel-rich.

The study of the effect of 74 rams of flame on the observed signal is based on the observed infrared radiation. This is consistent with the hypothesis that much of the radiation is due to radiation from excited combustion products. carbon dioxide complete combustion of the organic sample to hydrogen and water, if any.

It seems that only relatively high concentrations are achieved in flames, so the concentration of CO, for example, is It seems that the highest value in a flame is relatively high. C with increasing distance from the burner The increase in O7 concentration is counterbalanced by the decrease in temperature as well as the dilution effect from the entrained air. be killed. The combination of these factors is maximal at the point above the secondary burner. It is expected that this will result in a signal of From the results obtained, the visible part of the secondary combustion zone The point at the tip of the minute corresponds to the highest concentration of excited combustion products. This best is Because it is located at the tip of the flame.

It is surprising that the observed signal is very unaffected by the fuel to oxidizer ratio. do not have.

A series of studies were conducted to determine the effect of compound structure on the observed signal. . A series of three congeners of organic compounds were selected based on availability. No. Figure 8 shows the signal per mole of carbon as a function of the number of carbon atoms in the two molecules. if Once all the compounds have been introduced into the flame which completely burns to carbon dioxide, the horizontal Lots will be obtained. Figure 8 shows the signal obtained per mole of carbon in the compound. indicates that it depends on the type of compound as well as the number of carbons in the compound. long chain The decreased response observed with the compound is probably due to the compound's insensitivity to carbon dioxide. It is the result of complete combustion. Similarly, the difference in response between saturated and aromatic compounds This is undoubtedly the result of differences in the ease and degree of combustion. Actual mechanism of signal generation It is clear that the response of the system is compound dependent, regardless of the It is. As a result, quantitative measurements are possible using individual calibration curves.

A monochromator can be used to study the sensitivity of the system at wavelength. In order to improve this point, the Pb5e photoconductive detector was evaluated using the apparatus shown in Figure 2. did.

These detectors are about 2 orders of magnitude more sensitive than the thermistors and 1 to S It responds over the wavelength range of pm. Other detectors suitable for flame infrared radiation detection are , indium antimond and mercury cadmium telluride.

In this embodiment, a lead selenide detector was chosen for its cost effectiveness. Pb5e test Since the output device is an intrinsic semiconductor (i.e., undoped), it has a long wavelength response wavelength. The cut-off is determined by the characteristic energy gap between the single valence band and the conduction band. . (Boyd, R, W,: Radiometry and the Det. eetton of 0ptical Radiation; John Wi iey: New York, 1983.10).

As a result, the detector response is such that the photon energy is equal to the bandgap energy. It decreases rapidly as it approaches . The peak response is 3 when operated at room temperature. ．． Occurs at 8 μm. When the equipment is operated while cooling, the peak response is more shift to longer wavelengths. In addition to the shift in peak response wavelength, the dark resistance The resistance and time constant also change with cooling. For example, according to the manufacturer's specifications.

Cooling increases the dark resistance by 25°C and the time constant by 5.3%/°C. de Cooling with rye ice (-77°C) or liquid nitrogen (-196°C) increase the detection degree (D). The equipment used in this study has a detector temperature of -10°C. Equipped with an electric cooling system to keep the heat flowing.

Two factors are important in studying the influence of operating conditions on the performance of Pb5e detectors. - was explored. Effect of voltage used and effect of chopping frequency. Figure 9 shows 10 timemethanol/water mixture from the liquid chromatograph at a constant rate of 2-7 minutes. Bias voltage for the signal observed at 4.3 μm when delivered to the burner shows the effect of

From the figure, a threshold voltage of 10 volts is required to produce the lowest measurable signal. I understand. At bias voltages higher than 15 volts, the signal increases with increasing bias voltage. increases almost linearly. 30 volt bias voltage.

Real vs. 1 was used in all subsequent studies.

In all of the above experiments, the noise relative to the signal is observed to be constant. Ta. Bias in an effort to determine possible sources of noise in a system The filtered dC used to provide the voltage! [source.

Replaced by 30 volt battery. This substitution is based on the observed noise by a factor of 5. This reduced the For this reason, 30 points)! The pond is the next fruit of experiment 1. del! to provide the bias voltage in the experiment. Used in place of source6.

The other factor studied was that when pure ethanol is drawn into a flame at a steady rate, , was the effect of chopping frequency on the observed signal. Figure 10 shows this Presenting the results of the research. From the figure, the largest signal is around the chopping frequency of about 90Hz. I know what I can do. Based on this study86) Iz chopping frequency is A Pb5e detector was used in all studies in Experiment 1.

The 0.5 m monochromator used in this study was simple due to its availability in the laboratory. and not based on optical considerations. In fact, shorter length A more distributed system would have been preferable. Equipped with a grid of 150 grooves/- and the system has an inverse line dispersion of 13 nm/-, which is This is much lower than what is needed for infrared work. In addition, tj: Because it is wider (3-) than the width of the Pb5e detector (1 helmet), the two-dispersion system is , with a base equal to 0.04 μm and a 7 rat peak equal to 0.01 μm K. It was characterized by a trapezoidal slit feature. Regardless of the non-ideal slit function, The effective cost of the system is approximately half the molecular radiation band (~0.4 μm) being studied. Much smaller than the width of a minute, distortion on the hand-shaped device is not a problem. Expensive As resolution is not required, shorter focal length systems and the associated The higher the value in terms of dispersion.

As current systems generate more energy from the infrared band, have concentrated it on the detector rather than distributing it on either side. Yo Measuring the integrated band intensities with a system of lower resolution is therefore would be expected to significantly increase the sensitivity of the system.

The hydrogen/air flame has its low background near the 4.3 μm COz band. selected for de. Figure 11 shows hydrogen/air flame detection using a Pb5e detector. The results obtained for the acetylene/air flame systems show a comparison of vectors. vinegar. The amount of carbon obtained with an acetylene/air flame is the same as that obtained when using carbon-containing fuels. The results are representative, and about Bunsen's flame Plyler (Pl. yler.

E, Ni; J, Res, Nat, Bur, 5tand, 1948 ．． 40°113) is consistent with Kutle. 4.3μm radiation ban This is because the amount of carbon dioxide depends solely on the excited carbon dioxide.

It is not present in significant proportions in hydrogen/air flames. On the other hand, the 17μm band , both water and carbon dioxide and therefore present in both flames. hydrogen/air The notable difference in the tin flame compared to the flame of Not observed when Gon's flame was used. Hydrogen/20th Oxygen/80th It is expected that the use of Gon's flame will result in low background at 4.3 μm. It was done. That is, compared to air, this gas mixture did not contain carbon dioxide. It is from. Since no reduced background was observed, 20% oxygen The use of the 80% argon gas mixture was discontinued.

When an organic compound is introduced into a hydrogen/air flame, the radiation observed at 43 μm is truly two-dimensional. diacid introduced into the flame to prove that it is due to the emission of carbon oxide The gas obtained when ethanol is introduced into the flame is compared. Figure 12 shows that the same spectrum shows that organic compounds are burned or diacids are burned. shows that carbon dioxide is formed whether or not it is introduced directly into the flame.

Figure 13 shows the values obtained at 4.3 pm as a function of the flow rate of carbon dioxide introduced into the flame. Indicates the number. Figure 14 shows various volumes of ethanol eluted from a liquid chromatograph. The signal obtained when Zero offset observed by liquid chromatography This was attributed to background signal due to methanol in the elution solvent. both The experiment yielded a calibration curve that matched the results obtained in the nondispersion studies by Thermistor. In contrast, it curved upward. This upward bending of the growth white line indicates that alkali metals It is a remnant of the effect caused by ionization when introduced into the flame. How about the explanation? , the effect clearly includes only carbon dioxide. it is.

It is not observed when both carbon dioxide and water bands are monitored simultaneously. It is the body.

Only two strong bands (Z7 μm and 4.3 μm) approach the Pb5e detector. observed at wavelength intervals that can be Among the two bands, it is carbon dioxide. The 4.3 pm band appears to be the most useful analytically since it arises solely from the presence of Ta. It didn't seem necessary to change the wavelength, so a monochromator In an effort to increase the amount of optical processing and increase the sensitivity, high-frequency optical filters are used. replaced by the ter. By this means, the wavelength response of the system is the detector's short wavelength cutoff at lower wavelengths and the response of the detector itself. limited by higher wavelengths. Replacing the monochromator with a filter increased the sensitivity by about 2-3 orders of magnitude.

To demonstrate the potential of infrared radiation as a means of detecting organic compounds introduced into a flame. For liquid chromatography, a mixture of methanol, ethanol and propatool and detected by infrared radiation using a Pb5e filter arrangement. did. Figure 15 shows the results obtained for injection of 50μ of an equal volume mixture of three components. shows.

The 4.3 μm infrared radiation is sensitive enough to detect small amounts of organic samples introduced into the flame. bring the means. Since the emission wavelength does not change, a relatively low-cost filter device can be used. Can be configured to monitor desired emissions. The detector detects both liquid and gas Suitable for chromatography applications. Use of gas chromatograph detectors The background is removed from the eluent present when a methanol/water mixture is used. is easier to construct than with liquid chromatography due to the absence of a be.

The experiments reported in this application were performed with laboratory available equipment. The bar used The inner assembly was selected based on its availability in the laboratory and is not necessarily an ideal system for chromatographic detection. it's a bar This solution is not recommended because the flame produced by the ner is much thicker than is actually needed. Further suitable burners for use are described below in Experiment 2.

Experiment 2 The experimental setup used for this second study is shown in FIG. Hamamatsu Lead selenide photoconductive cell (P4O10-1, Hamamatsu Corp,... San Jose, CA) as an infrared detector, and the following specific design It was positioned to look into the hydrogen/air flame maintained in burner 160, which was turned on. high Tsuka Filter 168 (Corion Corp.

Holliston, MA) (with short wavelength cutoff of 3.5 pm) in the housing in front of the Pb5e detector 164 described in Experiment 1; 3. A response of 5 μm to about 5 μm was provided to the detection system. This training for the detector The power supply and preamplifier group circuit used in the study were also the same as described in Experiment 1. flame The radiation is modulated at 90 Hz into a chopper 165 configured in the laboratory. Ta. Modulated signal Fi, Model 128A Pr1nceton Ap plied Re5earch lock-in amplifier (Pr1nceton Ap pltedRe5search.

The amplified signal that enters the input of Pr (neeton, NJ) is Varian Displayed on an Aerograph strip chart recorder. M odel 3120TX BILscom-Turner digital data acquisition System (BaseomTurner Inatrumenta, Norvo od, MA).

Store and display data for the experiments in which peak area measurements were made. Ta.

Model 705 Varian Aerograph Gas Chromatograph (varian Instruments, Pa1o Alto, OA) Open and inlet the flame infrared radiation detection system for gas chromatography. to evaluate system performance.

Chromasorb W-T (packed with 10% 0V-101 on P”/ It was used with a 4” (0,635 cm) stainless steel column. The GC column was connected to the detection system using an outlet on the side of the romatograph.

4" (0,635) GC column and 0.10" (0,254(7)) OD The interface between the stainless steel capillary (burner system) and It was made with an adapter made from wood.

Mount and detector shield 11. Made from aluminum sheet metal and Detection from thermal forces and air drafts caused by GC opening or other heat sources (The detection system detects heat from people moving around the room.) reasonably sensitive). The side of the baffle surface facing the detector is Flatten back to avoid reflection of IR energy from the surroundings into the knit aperture. It was painted like that.

Column carrier gas flow and pressure were calibrated for helium flow in Figure 16. Brooks Instrument Division current meter 169 (B rooks Instrument]] visfon, Ernerson E Electric Co., Hatfield.

PA). The metering valve and separator Arai are helium supplied gas. placed on the line. All gas measurements were performed upstream of the GC and column. .

All experiments were performed with a 30 minute warm-up period to allow the area around the detector to reach thermal equilibrium. This took place after the warm-up time.

The radiation from the flame is chopped at 90) (z and 30 volts obtained from a series of batteries). The default detector bias voltage was used. Injection is standard 10 and 50μ in a syringe (Hamilton Co, Reno, Nepal) and a gas supply. In the sample, an SO PT gas syringe (Hamilton Co.

Reno, NV). All chromatograms are listed elsewhere. A carrier gas flow rate of 540 d/min was obtained. All compounds F used i, Eastman 98 CH was reagent or spectrometry grade, except for methane. It was made.

All experiments where the detector response for different carrier gas flow rates was measured. , the temperature of the GC oven is such that the stationary liquid phase remains constant as the sample flows down the column. The value was kept high enough to avoid interaction of the sample with. This way is , which minimized the effect of all columns altering the readings obtained in these experiments.

For injections smaller than 0.5 μt, the solution of the compound of interest is sampled by the column. prepared in a solvent with a higher boiling point than the sample that can be easily separated from the sample. O The temperature of the oven is then kept above the boiling point of the compound of interest, but only to a maximum of 7 separations. lower than that of the solvent to minimize the effect of the column on the sample. .

Small amounts of various gaseous samples (Matheson Gas Pro-duets) , 5eeaneus, NJ) were collected over water from leftcher bottles. . The chromatographs of these gas samples are transferred into the chromatograph using a gas syringe. It was obtained by injecting 500 μm of gas into the sample.

The chromatogram obtained for unleaded gasoline was obtained by holding the column temperature at 55 °C for 4 minutes. This was then obtained by raising the temperature to 200°C over 7 minutes.

The detector system used in this study was described above with respect to Figure 2, and the system It was found that the same operating conditions were sufficient for this task. awesome According to consideration I, the commercially available chopper used in the above research could be assembled in the laboratory. It was replaced by a smaller unit using a synchronous AC motor. radiation to the detector Since no focusing optical components were used, the detector/chopper combination It is important to keep the flame close to the flame.

This could only be achieved by a small chot, 4-. Pacgra from various sources The sound signal minimizes the field of view of the detector and its inner surface minimizes reflections. A sheet metal baffle coated flat to prevent small particles seen by the detector. The area was minimized by shielding. This shield also has a sky effect that affects flames. Air draft was kept to a minimum. A diameter of 106n used as a focal element in the above study. The use of a spherical shape increases the area required for shielding to an unacceptable amount. Because it seemed like it would let me do it.

Rejected.

The atomic absorption burner unit used in the above research is The flame is also very large, so a smaller specially created pre-mix burner is required. - (Figure 17).

A special burner, schematically shown in Figure 17, uses a small hydrogen/air premix Designed to generate flame. The burner is made from a block of aluminum. and is held in the body 170 by a rubber O-ring seal 172. A burner body 170 having a mixing chamber 170a and a burner rad 171. It became. Openings 173a and 173b on the side of the burner body allow the burner to Swagelok (Crawford Fitting Co.)

5alon, OH) connected to the combustion gas supply by pipe finishing.

The burner system described in this application consists of a series of stainless steel capillary tubes 174. Generates a small, stable flame. These tubes 174 are approximately Z5on long very slow hydrogen/air branch without any problems from flashback. Enables the use of gas flow rates. Combustion gas is transferred to a burner using epoxy cement. - ODo fixed in a small hole in the head, 10" (0,254Qll) and Circular collection of 6 stainless steel capillaries with ID O,06” (0,1524) (Figure 17.1) and exited the burner head. The process performed in this application In the inner design, six capillaries arranged in two circular collectors are used for combustion gas. It was used to form an orifice.

A circular collection of capillaries passes the column eluent directly into the center of the hydrogen/air flame. the center, which flows directly into the air and therefore acts as a connection between the burner and the gas chromatograph. surrounding the capillary tube 175. Center capillary 175Fi, bent at right angle and side opening 176 through and exited the burner body and was retained by a rubber seal to the tube finish.

The new burner design must emphasize 2.

It has three important advantages. The rate of sample addition to the flame depends on the carrier gas flow rate. Since it is determined only by the flow velocity of combustion gas and not by the flow rate of combustion gas, the The rate of sample addition varies independent of the combustion gas flow rate, thereby increasing the flame size. Avoid changes in concentration or stoichiometry.

By introducing the sample directly into the flame through the central capillary.

Peak broadening associated with mixing chambers is avoided. The capillary has a small inner diameter [: ID O,06" (0,1524 tan)], the capacity after the column is i & small. (0.5Wd, /30C length of tube). After the horsefly, a capillary with a narrow inner diameter The use of directs the center of the flame into an ascending gas jet with high linear velocity. (For example, 40 -7 min carrier gas flow rate results in a linear velocity in the capillary of 40 crn/sec) . An exposed beam of length 30G moving from the end of the GC column to the flame at a speed of 40α/s The travel time for the eluted sample through the capillary tube is approximately 750 ms. line The speed is significant for the largest sample volume investigated in this study, even with insulation or is sufficient to avoid condensation of the atomized capillary wall soil sample without heating. It looks like a sea urchin.

First, the eluent capillary is connected to the G C. Outside the oven or burner body for a short length of time exposed to ambient air. It was thought that it should be insulated. This part of the eluent capillary should be heated. The possibility that the

Any of these options will work for this experiment, regardless of sample size. Any of the samples studied in was found to be unnecessary. In this study The flow rate of the carrier gas used (which is the typical phase gas for the designed 〇〇 column) (the flow of gas) causes the gas velocity in the capillary of the eluent to become too fast. It is believed that there is not enough time for the components of the sample to condense on the walls.

Typical carrier gas flow rates of 30-40-7 min were used; The flow was used without any problems.

The combustion gas flow velocities of 300 d/min and 800 m/min are applied to hydrogen and air, respectively. It was used accordingly. This combination of flow rates produces a flame approximately 204 cm high and 3 W13 wide. and the predetermined combination of metering device and capillary size produces flame pulsations or burnouts. It produced the smallest flame used for burning.

The ratio of fuel to other agents used corresponded to a roughly stoichiometric mixture and resulted in a good signal. produced the smallest possible flame consistent with the conditions. The best signal-to-noise ratio is when the detector obtained when the flame was positioned to look at the top of the secondary phosphorus zone.

A problem arises in aligning the detector with the appropriate flame band because the flame itself is not visible. It was. Add a small amount of 1M sodium chloride to the buffer to make the flame visible for alignment purposes. was applied to the outer surface of the inner capillary to produce visible sodium (yellow) radiation.

This sodium signal lasted for some time after the system was aligned, but the flame was still yellow. Detector signals seen in chromatograms of a few compounds taken during detection had no impact. One advantage of flame infrared radiation detection systems is that they is that it does not respond to visible radiation from other external sources, such as indoor lighting.

Another advantage of the observed flame infrared radiation detection system is that nitrogen reduces the detector response. This was achieved by using helium as a carrier gas instead of helium without any change. .

Since the signal from the Pb5e detector changes due to temperature changes in the surrounding area, it takes about 30 minutes. It turns out that a warm-up time is necessary. Burner/detector combination When all components of the system have reached thermal equilibrium (approximately 30 minutes), a steady base A sline was obtained from the recorder.

The area of the flame from the infrared radiation from the chromatograph oven is placed on the baffle surrounding the flame. It has the additional effect of insulating.

It thereby reduced the background signal from the detector. Before buckle installation Before further chromatography is performed, the change in GC open temperature This resulted in a baseline shift that required stabilization time. To shield F i, a slight base radiation that may be due to changes in the temperature of the carrier gas introduced into the flame; Almost completely eliminates the effect of GC oven temperature on the detector signal, except for the change in was excluded. This slight baseline shift can be seen in Figure 18; A temperature programmed chromatogram obtained by injecting 5μ of leaded gasoline is shown.

The chromatogram shown in Figure 18 also shows that the flame infrared radiation detector is It has been proven that it has been successfully used as a detector in matographic separations. This lab Since the purpose of the study was to verify the performance of the detector, a sample of gasoline was No effort was made to optimize or improve the separation conditions.

Figure 19 shows two different volumes of methane in the chromatograph as pure samples. Shows typical peak shapes obtained from the system when injected. Column effect shadow To study the response of the detector itself to various compounds without The GC oven was maintained at a temperature above the boiling point of the compound under study. This is a sump Do the le.

indicated by similarity in retention times (i.e. within seconds of each other) for various compounds. The sample was moved through the column with almost no interaction with the stationary phase. This method is , also resulted in a highly symmetrical peak as shown in FIG.

In contrast to the peak area, the comparison of peak Fi and response is based on the peak height. It had to be done based on. Through much of this work, integration of peaks Highly symmetrical peaks were desired, as this was not possible with the experimental equipment used. Ta. It is because these peaks are related to the peak height and the amount of compound present (i.e. the peak This is because it showed the best correlation between To obtain peaks of similar shape, A single carrier gas flow rate of 40 d/min was used throughout. Compounds that exist The use of peak height as a measure of quantity is based on the data obtained on the calibration curve. justified by the goodness of fit.

Figures 20.21 and 22 show dichloromethane, trichlorotrifluoroethane and Figure 3 shows a plot of peak height versus injection volume for carbon tetrachloride and carbon tetrachloride. These compounds Things.

chosen based on availability and the ability of the flame to burn them to carbon dioxide. I checked the power. Hydrocarbons and other compounds such as aromatics and cycloalkanes are actually Although it was clear that they would serve as fuel for the flames, other compounds, such as the halide used above, It was not clear whether the locarbon would burn enough to emit a signal. From the diagram , the response is reproducible and is a linear or nearly linear function of the amount injected. I understood. This is true even if complete combustion to carbon dioxide is somewhat questionable. even occurred for all of the compounds studied. Regarding carbon dioxide shown in Figure 23, Create a calibration curve to determine whether the phenomenon observed by the detector is in fact carbon dioxide. The obtained signal also indicates the amount of carbon dioxide introduced. It shows that it changed linearly. The data shown in Figure 23 is based on atomic absorption burners. In contrast to the results obtained in the aforementioned studies using It should be noted that it shows a linear relationship between The straight line obtained in this study Connection: smaller flame, lower amount of injected carbon dioxide & sample introduction This seems to be due to the use of methods.

Figure 24 shows carbon dioxide, pentane, 1. L2-) Licro l’-1,2,2- ) Five comparisons obtained for IJ fluoroethane, dichloromethane and carbon tetrachloride Shows a positive curve. In Figure 24, each point represents a single injection, and the average degree of regeneration is 7- Represents 75 chi. These curves were all obtained under identical conditions and the detector Plotted in moles of compound injected to perform cross-comparison of responses. charcoal Compounds such as hydrogen oxides, aromatics and cycloalkanes act as fuel in flames was clear, but it was unclear whether the halocarbons would burn enough to generate a signal. It was not clear (flame ionization detectors are not well known for such compounds). gives a poor response as shown). From Figure 24, the flame emission system The membrane responds well to 39 halogenated compounds, with carbon dioxide having the largest response ( i.e. the maximum slope). The detector response is based on the carbon dioxide present in the flame. These curves are plotted in Figure 24 because they should be proportional to the number of moles of carbon. Reveals that none of the organic compounds are completely oxidized to carbon dioxide in the flame show.

The calibration curve for propane (not shown) is almost more accurate than that obtained for carbon dioxide. It is interesting that it has a slope three times that of the previous one, indicating almost complete burnout during the flame. . the expected value for complete combustion (i.e. the value for carbon dioxide in the case of methane). 5 times the sponse, 1,1.2-)lichloro1.42-trifluoroethane (e.g. twice the response with respect to combined carbon dioxide) and the four types of compounds shown in Figure 24. A comparison of the responses obtained for all four species shows that all four species only burn about 7-11%. Which indicates that. Therefore, a flame infrared radiation detector consists of a compound-dependent response (similar to FID) indicates that many compounds burn to roughly the same extent. appear. This conclusion is based on the fact that 15 different devices, Pn-A, gave roughly the same signal per mole of carbon. Further support is provided by preliminary studies with lucan and cycloalkanes.

The table below shows the peak heights obtained for four different compounds in a series of 1μ injections. shows the reproducibility of the response. Each entry in the table is a single note. represents the height of the peak obtained for the input. The peaks observed for all four compounds The average relative standard deviation of the peak height was 2-75%.

m = Table Reproducibility of response for 4 types of compounds CC4F-CClF2 Cs Hp CC14CH〆4 Relative peak height 50 64’31 49 standard deviation 0, 8 Z O, 91 relative standard deviation L7 a5 3. IZ7 The linear dynamic range of the detection system was studied using pentane as the test compound. It was. Figure 25 shows the chromatography for sample volumes ranging from 0.02 to 50 μt. Introduced into the graph is the volume of the methane sample versus the peak height of the Chromadog2F A log-log plot is shown. If the sample volume is larger than 0.5 μt, The pure sample was introduced into the chromatograph by direct injection. From 0.5μt The signal increases with a small sample volume and an appropriate amount of methane dissolved in hexane. obtained by injecting.

Different degrees of amplification are required to obtain data over this range of sample volumes. required, which required changes in the gain settings of the lock-in amplifier. these The positive Z” of gain change, − sign, for injecting 1μ of xane under different amplifier settings. This was checked by comparing the signals obtained from the lowest level to A descending curve of approximately 20 to 30 µm is produced, indicating a possible response to the injection of a volume of vinegar. This descending curve I of the calibration curve;! By three or four factors, they are signal The use of peak height instead of peak area as a guideline for injection of large amounts of sample The consequences include column runoff and self-absorption of radiation in the flame.

If the downward curve is due to self-absorption, the expected log-1log growth curve The slope will be half. As expected, the straight line in the log-1log plot The measured slope of the section is one, and there are many that can be worked in the curve area. It appeared that the slope was not halved because there were no data points for . the result, The signal drop-off is thought to be due to the column effect, and the prediction is that there is a large This was corroborated by P-detection following the recorder trace of the peak.

From the data shown in Figure 25, the dynamic range of the flame infrared radiation detector is 104 It was rated as being at the top of the list. From this data, the smallest volume of pentane that could be found is If the quantity is o, ozpt, this is about 4.6 x 10' q/a. This would correspond to the detection limit of tan. The signal obtained for 0.02μt is packed This is actually a very modest detection limit since it can be easily measured above ground. This is a good evaluation.

To determine the effect of compound structure on detector response, the response The data is a number series that is nestable in the laboratory and compatible with the GC column used. were collected for the following compounds. The compounds used were categorized into three or four based on their structure. classified into the category of , and substituted with n-alkanes and cycloalkanes Contains methane and ethane. Gaseous compounds such as methane.

- Carbon oxide and carbon dioxide inject 500 μt of the compound by gas syringe It has been extensively studied. The response for various liquid compounds is 1 μt pure obtained by injecting a compound. for each liquid compound injected. So, what is the response per mole of carbon?

Calculated from the injection volume, the density of the liquid, the bulk weight of the compound and the number of carbons in the compound .

Figure 26 shows the relative response obtained for one equal volume (i.e., equal mole) of one carbon gas. If both methane and carbon oxide are completely burned to carbon dioxide in the flame, If baked, their responses are equivalent to those obtained for an equal amount of carbon dioxide. That would be expected. The data shown in Figure 26 is real! They appear to be equal within error. Because I can.

This suggests that the hypothesis of complete combustion of these gases is correct.

Figure 27 shows the amount of carbon per mole as a function of the number of carbons present in 15 compounds. The relative responses obtained are shown.

Table ■ shows the injection of 1μ of 15 compounds with the calculated signal of 1 mole of carbon itself. We present actual data obtained for

Table ■ Relative response per mole of carbon for the compounds studied Cyclopantane 65 70.13 0.745 5 1.22X10@Cyclo Hexane 62 84.16 0.779 6 1.12X106 cyclohebuta s5 9S, 18 0.81o 7 9.52xtO' cyclooctane 2 0 11Z21 0.839 8 3.34X10' Methylcyclobequinane 6 3 99.18 0.769 7 1.15 X 10' dichloromethane 19 ．． 3 84.94 1.336 1 1.23X10' trichloromethane 14 ．． 5 119.39 1.489 1 1.16X10'Tetrachloromethane IZI 15L, 84 1.594 1 1.17X10・n-pentane 61 ．． 5'113 0.626 5 1.42X10'n-hexane 60 86 ．． 17 0.659 6 1.31X10’n-hebutane 60 100.2 0.684 7 1.26X10” Ethanol 37.9 46,07 0.7 89 2 1.11X10' Bromoethanol 35.5 10B, 94 1. 46 2 1.32X10' trichloroethano + 24 131.4 1.46 6 2 1.08 Figure 27 shows that up to about 7 carbons, roughly the same relative response occurs for the number of carbons in the compound. Indicates that the result is obtained regardless of the number. This means that if it does not burn completely to carbon dioxide If so.

All of the compounds studied except for the above two types showed that the influence of the number of carbon atoms or the structure of the compound This suggests that there is very little and the combustion rate is about the same. Cycloheptane and cycloheptane The exception to this rule obtained for clooctane is the This may be more obvious than it actually is, since the shape of the ku is not symmetrical. As a result, the generated signal The use of peak height as a quantitative measure of the actual peak area It's not an indicator. Excludes data on cycloheptane and cyclooctane and the average signal per mole of carbon in the coating is in lXl0' units, which is the diacid This corresponds to about 50 g of the signal per mole of carbon predicted for oxidized carbon. This comparison suggests that the liquid sample was not completely converted to carbon dioxide in the flame. do.

The effect of carrier gas flow rate on chromatographic peak area is determined by the detection system. to determine whether it operated as a concentration-dependent detector or a mass/flow rate-dependent detector. researched with great effort. These two different detector response categories are Support for chromatographic peak area obtained for a given sample size They can be distinguished from each other based on the effect of gas flow velocity. For concentration-dependent detectors, chromatography The peak area of the graph varies inversely with the carrier gas flow rate, while the mass/flow rate detection The peak surface of the chromatography is independent of the flow rate of the IFrFi carrier gas. (McNair, H, M, Bonelli, E, J, Bag ieGas Chromatography, 5th edition, Varian Ing trumvat Division, Pa1o Alto, CA, 1969. 81~5=-di).

Figure 28 shows that the peak height in fact increases with carrier gas flow rate. , the relationship is not strictly linear. Figure 29 shows the flow rate of carrier gas faster than 30 mg/min. At flow rate, the area of the chromatographic peaks increases slightly with increasing carrier gas flow rate. It shows that it only changes slightly.

Apparent deviations from the mass flow velocity line, motion are due to flame cooling, incomplete mixing and dilution. Attributable to Increasing amount of helium to the flame as carrier gas flow rate increases The introduction of.

As the flame gas is diluted, the flame temperature decreases slightly. both of these factors contributes to a decrease in detector response. In addition, sample contamination by flame gas If so.

If the flow rate is high, the combustion will not be complete, resulting in incomplete combustion.

At very slow carrier gas flow rates (3 ONt, 7 min or less).

Although the reproducibility of peak area measurements is greatly impaired (Figure 29), on the other hand, romatograph The height of the peak of the peak approaches the limit value, which is a win. Under these slow flow conditions The overall view of the carbon dioxide present in the flame in all cases is less and a smaller signal sample removal is the main step. In addition, the slow carrier gas The flow rate means a longer retention time and a correspondingly broader peak band.

As the band of peaks increases, the sun introduced into the flame in all cases The concentration of pull decreases. The minimum concentration of carbon dioxide is measured by a flame infrared radiation detector. Increased sample mixing and combustion is required to produce a quantifiable signal. Decreasing the flow rate of the carrier gas while still favoring quenching can reduce detection below the limit. It's going to be a flaming COz level. At these flow rates.

Both response and reproducibility should decrease in the observed manner.

We report the detection limits obtained for SiR by using a flame infrared radiation detector. Before proceeding, we will discuss how detection limits are factored into chromatographic measurements. is significant. Since the flame infrared radiation detector corresponds to the way the mass flows, the detection The output limit will depend on the minimum baseline noise and detector response. detection The response R of the detector is determined by plotting the signal S versus the mass flow rate Mf at the detector. It can be determined from the slope of the calibration curve obtained.

R=ΔS/ΔM f(1) The mass flow rate expressed as wq/sec is the band of the resulting chromatographic peaks. area 1] is calculated by dividing the total mass (W) of the injected sample.

If you obtain a calibration curve by plotting the signal versus the mass flow rate into the detector (i.e. If S = RMf) is removed to a flow rate value of a much smaller mass, the signal will no longer be clogged. A point will be reached where the line of the matogram cannot be distinguished from the noise.

If this point is a signal equal to twice the root mean square (rrns) baseline noise, If so, what is the detection limit?

S = RMf = 2 (rmi baseline noise) (2). Mf Solving equation (2) for .

(Mf)dt=2 (rms baseline noise)/R(3) (in the formula (Mf)d is the minimum detectable mass flow rate (W?/sec) into the tH detector) becomes.

To compare the performance of erroneous mass flow rate of flame infrared radiation with thermal conduction detector (TCD). For this purpose, the flow rate of the smallest detectable mass is divided by the flow rate of the carrier gas to give CdL. (w?/1)=2 (rms baseline noise)/RF (4) (in the formula, F is the The flow rate of body gas (wt/sec), Cd/, is the lowest concentration that can be detected by the detector. ) becomes. The observed r　m　s baseline noise depends on the time constant of the amplifier. Therefore, it is important to specify the system time constant when reporting detection limits.

From equation (3) K, the detection limit for pentane is determined from the detector response measurement. The rms baseline noise estimation is for an amplifier time constant of 3 seconds. It was 4.6XIF'+19/sec. rms noise is on a peak-to-peak basis It was estimated to be -1/1 of the line noise. Detected for carrier gas flow rate of 40-7 min At the concentration of the sample entering the vessel.

The lowest detectable concentration of methane is given by equation (4) as 7×10−’Ql /- or IX 10-' mol/eXr of pentane. Standard temperature and pressure As the force, the fi! of the aforementioned pentane! # Degree is equivalent to 224 ppm on a capacity basis do.

For comparison, detections for similar compounds obtained by flame ionization detector (FID) The limit is on the order of 10””η/s, and with a thermal conductivity detector (TCD) The detection limit is on the order of 10-6 to 10-7 mol/- depending on the operating conditions. Considered superficially (Karger, B-L. et al.

An introduction to 5 separations e, Wiley.

New York, 1973.232-236A-di). From the above discussion, flame Although infrared radiation detectors are more sensitive than TCDs, they are much less sensitive than FIDs. I understand. Therefore a significant increase in sensitivity makes flame infrared radiation detectors competitive with FIDs. It is clear from the beginning that it is necessary. Nevertheless, as described in Experiment 2 The detector is just a prototype.

And considerable improvements in sensitivity are expected as detection systems become more precise and controlled. When a limited noise source is identified.

It's predictable.

Figure 30 shows methane, LL2-trichloro-L2.2-trifluoroethane, Synthetic sump consisting of a 1:2:1:3 mixture (by volume) of hexane and carbon tetrachloride We demonstrate the performance of the flame infrared radiation system under isothermal conditions for 300 nm. This chromatograph 5μ of this mixture was injected through an Apiezon L column kept at 50°C. I got more.

Pb5e detectors respond to intensity changes in the kilohertz range, making them suitable for flame infrared radiation detection. The relatively slow intensity changes produced during the elution of components from a gas chromatograph There is no difficulty in following.

Flame infrared radiation detection systems are relatively simple and inexpensive for gas chromatography. This indicates that the detector is

Compared to other detection systems currently in use, the use of infrared radiation has many advantages. Since the system is not based on thermal conductivity, nitrogen is not a thermal conductivity detector. It can be used as a carrier gas instead of the more expensive helium required.

The system described in this application is capable of displaying a wide dynamic range of radiometric properties. and The detector has a relatively fast response time, which It is possible to detect narrow chromatography that can be obtained by chromatography. This is a possible advantage.

The analytical applications of infrared radiation mentioned above center on the measurement of infrared radiation from carbon dioxide. However, other combustion products, such as oxides of nitrogen and sulfur, emit infrared radiation at other wavelengths. arise. Therefore, a detection system with three or four detector/filter combinations , which responds to the presence of carbon as well as nitrogen and sulfur.

said detection system Fi, the carbon dioxide produced by the combustion of the compounds introduced into the flame; , and appears to be largely unaffected by the structural properties of the sample. It looks ugly. They also do not respond well to flame ionization detectors, such as gases made of For example - the small capillary head burner of experiment 2 that responds to carbon oxide and carbon dioxide modified for use with body samples. The burner mentioned above has a burner head. The purpose is to direct the flow of gas from the gas chromatogram to the center of the At, the burner was modified for the atomized liquid sample. Center sample injection Remove capillaries and increase the number of small hole capillaries in the burner head from 6 to 19 increased (the internal diameter of the capillary was 0.6-). The total diameter of the burner orifice is 0 ．． It was 5m. Jarrell-AI+h model X- for the capillary head burner 88 atomic absorption cross-flow nebulizer and 3 length x 4 cIn diameter Teflon spray Installed the room. The nebulizer and nebulizing chamber are connected to the burner body (perpendicular to the capillary head). ) and attach the spray chamber/nebulizer assembly to the burner. It was attached to the burner body by press-fitting the lee.

A 1:l hydrogen/air flame stoichiometry was used for all measurements, and the fuel and The flow rate of the curing agent was kept at 200 d/min. A 1:1 fuel/oxidizer mixture has a height of approx. A stable flame of 4α×width 1G was generated. Infrared radiation is transmitted from the top of the burner to L56R. It was observed over the vertical part of one kun concentrated at a height of . Reagent grade liquid solution The sample was introduced into the flame via suction with a nebulizer.

All flame infrared radiation does not do nommy Mattson Cyg Obtained on a NUS 100 Fourier transform spectrometer. Fourier transform infrared radiation spectrometry This enables multi-wavelength nonmetallic analysis. Due to the complex nature of data acquisition.

A Fourier transform spectrometer is a multichannel device.

And therefore all infrared wavelengths can be monitored simultaneously. Nonmetal molecule radiation Since infrared radiation occurs in the vector region, all standard commercially available Fourier Conversion interferometers can be used without the need for special optics, beam splitters or detectors. Can be used. Fourier transform devices also have several advantages for infrared radiation spectroscopy. Ras. These benefits include: Units for both elemental and molecular analysis single instrument, high optical throughput, good spectral resolution, accurate wavelength recording (standard ), the ability to average the signal by co-addition, and the ability to perform vector subtraction. .

FIG. 31 shows burner 310 for Experiment 3. Mirror 312 and Fourier transform interferometer 314 schematically shows the arrangement of 314.

Using an aluminum mirror 312 with a focal length of 10 mm and a diameter of The radiation was focused and parallelized.

It should be noted that the infrared focusing mirror 312 Fi is placed approximately 30° off the optical axis. Ruru. No significant omission defects were observed.

Room temperature triglycine sulfate (TGS) detector (D*=2X10"WIFl" /'') and KBr beam splitters were used in the Fourier transform interferometer 314.

All spectra are with a resolution of 4 knee 1 with a mirror speed of 0.321:1117 seconds. Obtained. Beer-Norton medium (F2) apodization function Due to the use of IXX sphere rings and the nature of the separated lines in the emission spectrum, No phase correction was made. Instead, single beam powers calculate Plot the tremo of the Suscuttle in Figures 32 to 37, and the response on the device. No correction was made for

Choose a hydrogen/air flame to eliminate carbon dioxide emissions from the fuel gas. , excited the molecule of interest.

Otherwise, the measurement of carbon as carbon dioxide was severely compromised.

Figures 32 to 37 show carbon tetrachloride, methanesulfonyl fluoride, ■2/air flame Thick ground, methanol.

Characteristic infrared radiation for trichlorotrifluoroethane and tetramethylsilane Radiation is located in Kutle. These spectra are from F80 and CO: It clearly shows that the outer band is observed in the flame.

In other embodiments, the flame infrared radiation detector is combined with a flame ionization detector ( The same flame is used to perform both types of detection at the same time). Flame infrared detector yields a good quantification of the moles of carbon present in the compound.

-1 Flame ionization detector provides greater sensitivity for very small amounts of hydrocarbons vinegar. Additionally, flame infrared radiation detectors detect chemical compounds that are not observed by flame ionization detectors. For example - carbon oxides and carbon dioxide can be detected. Flame infrared radiation/flame ionization group An experimental schematic for a combined detector is shown in FIG. burner body 3 80 is the same as used for Experiment 2. Hydrogen/air.

Supply to burner capillary through Swagelok T 383a, 383b used as a fuel/stimulant mixture.

The sample is delivered through the central capillary tube 386. Flame ionization detectors Using two electrodes in assembly 382, a potential of approximately 300 VDC is applied by the power supply. Adjusted between electrodes. The electrometer measures the ion flow between the rows.

, infrared radiation is simultaneously detected by Pb5e detector 384. radiation from flame is modulated by the optical switch/(-385. Infrared detector 384 connects the electrode to ``See the laser beam'' (due to the blackbody radiation background), therefore the aperture device is infrared installed in the line detector unit.

Although the present invention has been described in relation to preferred embodiments comprising novel infrared detection means and methods, The purpose is not to limit the law, so that various changes may be made in accordance with the foregoing description. 1 drawings and as falling within the spirit and broad scope of the following claims. It is an object.

Engraving (no changes to the content) FIG.1 +30■ FIG.5 FIG.6 FIG.9 FIG, I.O. 2. Him 4.3 μm 2.7 μm 4.3 μm FIG, 11. IFIG, 11 ．． 2 FIG, l3 FfG, I4 FIG.I5 FIG.I9 T! 9 fear 4 side dish ゛゛゛　　　　　 FIG. 24 Two tank f (l otsu σ) to go to the night FIG. 28 FIG. 30 Mosquito shot γ Procedural amendment international search report 1I11e+Book 114-＾--ζMikanaishi PCT/US 88703798m1 +*A-’Aa*’c11”0PCT/US 8810379B

Claims (59)

[Claims] 1. Infrared detection means for detecting selected molecules of interest in gaseous samples wherein the means (a) excites any molecules of interest in the sample to produce a characteristic (b) means for emitting a certain infrared radiation pattern; (b) emitted by said molecule of interest; detecting a selected wavelength of infrared radiation at said preselected wavelength; (c) a preselected wave of infrared radiation; The wavelength is selected from the characteristic infrared radiation pattern of the molecule of interest. means provided between said means for excitation and said detector means; More means. 2. to evaporate a liquid sample and excite molecules of interest in the sample. 2. The method of claim 1, further comprising means positioned to evaporate said sample to said means. Infrared detection means included. 3. The means for exciting molecules of interest in the sample is hydrogen/air or hydrogen/air. Claim 11 or 2, further comprising a flame emitted by a torch that burns any of the enzymes. Infrared detection means. 4. 4. An infrared detection means according to claim 3, wherein said detector means is a lead selenide detector. 5. Infrared radiation according to claim 3, wherein said detector means is an indium antimonide detector. Detection means. 6. Infrared radiation according to claim 3, wherein said detector means is a mercury cadmium telluride detector. Detection means. 7. 4. The means for isolating preselected wavelengths is a monochromator. infrared detection means. 8. 4. The means for isolating preselected wavelengths is an infrared filter. infrared detection means. 9. The means for isolating preselected wavelengths is an infrared interferometer, and the detector 4. An infrared ray as claimed in claim 3, wherein the means includes calculation means for applying a Fourier transform to the electrical signal. Line detection means. 10. surrounding said means for exciting and said infrared detector means thereby said detecting. It is also recommended to include buffer means for limiting external infrared radiation received by the device. 3. The infrared detection means according to claim 3. 11. When molecules of interest are oxidized by the flame, they generate CO2 molecules, and Claim 3: The distinctive infrared radiation pattern includes peaks at 43 μm and 27 μm. The infrared detection means described. 12. (a) CO2 from any carbonate or calcinate contained therein; a means of acidifying the liquid sample prior to evaporation to generate (b) further comprising flame generating means within said means for exciting the vaporized sample. The infrared detection means described. 13. Identify objects of interest in gaseous samples by detecting characteristic infrared radiation. a method for detecting a selected molecule, the method comprising: (a) Excite any molecule of interest in a gaseous sample, thereby (b) the infrared radiation emitted by the excited molecule of interest; Isolate a pre-selected wavelength of radiation, which wavelength is characteristic of the infrared radiation of the molecule of interest. (c) infrared radiation when emitted by the molecule of interest; detecting the presence of said preselected wavelength of radiation; and (d) said preselected wavelength of radiation. emits an electrical signal when a wavelength is detected The way it is done. 14. 14. The method of claim 13, further comprising the step of vaporizing the liquid sample before the excitation step. Methods for detecting selected molecules of interest. 15. The excitation step is fueled by either hydrogen/air or hydrogen/oxygen. The method of interest according to claim 13 or 14, comprising the step of burning the sample in a flame of How to detect selected molecules. 16. 16. The method of claim 15, wherein said detecting step comprises the use of a lead selenide detector. How to detect selected molecules. 17. 16. The detecting step includes the use of an indium antimonide detector. A method for detecting selected molecules of interest. 18. 16. The detecting step includes the use of a mercury cadmium telluride detector. A method for detecting selected molecules of interest. 19. 16. The method of claim 15, wherein the monomolecular process includes the use of an infrared filter. How to detect selected molecules. 20. 16. The method of claim 15, wherein said isolation step comprises the use of a monochromator. How to detect selected molecules. 21. 16. The step of isolating and detecting comprises the use of a Fourier transform infrared interferometer. A method for detecting selected materials of interest. 22. 16. The method of claim 15, further comprising shielding the detector from external infrared radiation. How to detect selected molecules of interest. 23. The molecule of interest is CO2 and the characteristic infrared radiation pattern is 4 ．． 16. The selected fraction of interest of claim 15 comprising peaks at 3 μm and 2.7 μm. How to detect children. 24. Acidify the sample to remove any calcinates or carcinates present in the sample. 24. The interesting option of claim 23, further comprising the step of generating CO2 from carbonate. How to detect selected molecules. 25. the gaseous sample is a process gas and the molecules of interest are 16. The selection of interest as claimed in claim 15, which is generated by the combustion of contaminants within the gaseous sample. How to detect selected molecules. 26. The molecule of interest is CO2 and the inclusions are CO, CO2 and 26. A method for detecting selected molecules of interest according to claim 25, which are hydrocarbons. 27. 13. The molecule of interest is excited by electron bombardment in a gas discharge. Methods for detecting selected molecules of interest described. 28. The molecule of interest is bombarded with a second one by vibrationally excited nitrogen. 14. A method for detecting selected molecules of interest according to claim 13, wherein the selected molecules of interest are excited by 29. 14. The molecule of interest according to claim 13, wherein the molecule of interest is excited by photoexcitation. How to detect selected molecules. 30. In an infrared detection means for detecting selected molecules of interest in a sample. , the means (a) The flame pattern is a plasma generation means, (b) the flame injects the sample into the plasma and thereby Excite an arbitrary molecule that causes the molecule to emit a characteristic infrared radiation pattern. a means of emitting (c) means for concentrating said generated infrared radiation on an infrared radiation interferometer; (d) a Fourier on the output of said interferometer to detect said characteristic radiation pattern; (e) computer means for performing the transformation; (e) the presence and the existence of said selected molecules of interest; output means responsive to said computer means for providing an output indication of the amount of More means. 31. Selected molecules of interest are identified by CO2 and a distinctive infrared pattern 31. The infrared detection means according to claim 30, wherein the infrared ray detection means includes peaks at 27 μm and 4.3 μm. 32. The selected molecule of interest is a hydrocarbon, and the hydrocarbon is 32. The red colorant of claim 31, which is oxidized by the step to generate CO2 as a by-product of said oxidation. External line detection means. 33. Claim 32 further comprising means for vaporizing the liquid sample prior to injection into the flame. The infrared detection means described. 34. whether the means contains any calcinates or carbonates contained therein; 32. The method of claim 31, further comprising means for acidifying the sample to generate CO2 from the sample. Infrared detection means included. 35. The means for concentrating the emitted infrared radiation comprises a three mirror assembly. The infrared detecting means according to claim 30. 36. the molecules of interest include CO2 and H2O, and the output means When the Errier transform shows characteristic radiation peaks at 4.4 μm and 2.9 μm, 31. An infrared detection means according to claim 30, which provides an indication of the force ratio. 37. Selection of interest in samples by detecting characteristic infrared radiation A method for detecting a molecule in which the method is (a) the presence of chemicals in the sample to produce the emission of a characteristic infrared radiation pattern; Excite any molecule in the heart, (b) detect its infrared-edge radiation by an interferometer, and (c ) to detect the characteristic infrared radiation pattern mentioned above. (d) When the characteristic infrared pattern described above is detected, the electric signal is transmitted. generate a number The way it is done. 38. The excitation step produces CO2 molecules formed by oxidation of selected molecules of interest. 38. The selected fraction of interest of claim 37, comprising burning the sample to excite the How to detect children. 39. If the sample is a biochemical sample and the molecules of interest are dissolved in CO 38. A method for detecting selected molecules of interest according to claim 37, wherein the selected molecules are: 40. CO2 from any calcinates or carbonates contained in the sample 38. The method of claim 37, further comprising the step of acidifying the sample to generate How to detect selected molecules of interest. 41. 41. The selection of interest of claim 40, wherein said sample of interest is a water sample. How to detect selected molecules. 42. 39. The selected molecule of interest of claim 38, wherein the sample is a water sample. How to detect. 43. 39. The selected sample of interest of claim 38, wherein said sample is an industrial effluent. How to detect molecules. 44. to generate CO2 from any organic compounds contained in the sample. 39. The method of claim 38, further comprising the step of oxidizing the sample. How to detect. 45. 45. The selected molecule of interest of claim 44, wherein said sample is a water sample. How to detect. 46. 45. The selected sample of interest according to claim 44, wherein said sample is an industrial effluent. How to detect molecules. 47. 39. The selected sample of interest of claim 38, wherein said sample is a halo-organic compound. How to detect molecules. 48. Combined infrared to detect selected molecules of interest in a sample and in a flame ionization detector, the means (a) Place a molecule of interest in a flame to excite any molecule of interest within it. (b) means for introducing a sample containing the sample of interest when excited by the flame; detecting infrared edge radiation emitted by the child and emitting a first electrical signal in response to the infrared radiation; infrared detection means, (c) a first means of creating an electric potential in the flame; (d) detecting any ionic current in the flame; and a second means for emitting a second electrical signal in response to the presence of one ionic current ( e) said first or said second electricity for indicating the presence of said molecule of interest; A detector consisting of means responsive to a signal. 49. further comprising means for isolating a preselected wavelength of the infrared radiation, wherein the wavelength is selected from the characteristic infrared radiation pattern emitted by the molecule of interest; is provided between the flame and the infrared detector means according to claim 48. External line and flame ionization detector. 50. evaporating a liquid sample and positioning the flame to evaporate the sample; 49. The combined infrared and flame ionization detector of claim 48, further comprising means. 51. The detector means is selected from a group of detectors, and the group includes lead selenide detectors, insulators, and lead selenide detectors. Claim 4 comprising a dium antimonide detector and a mercury cadmium telluride detector. A combined infrared and flame ionization detector according to claim 9 or 50. 52. Claim 4 wherein said means for isolating preselected wavelengths is a monochromator. 9. The combined infrared and flame ionization detector of claim 9. 53. Claim 4 wherein said means for isolating preselected wavelengths is an infrared filter. 9. The combined infrared and flame ionization detector of claim 9. 54. The means for isolating preselected wavelengths is an infrared interferometer, and the infrared 50. Claim 49, wherein the line detector means includes calculation means for applying a Fourier transform to the electrical signal. Combined infrared and flame ionization detector included. 55. 49. The combination of claim 48, wherein said means for detecting ionic current is an electrometer. Infrared and flame ionization detector. 56. One of the molecules of interest when oxidized by the flame generates a CO2 molecule, The characteristic infrared radiation pattern includes peaks at 4.3 μm and 2.7 μm. 50. The combined infrared and flame ionization detector of claim 49. 57. thereby limiting external infrared radiation received by the infrared detector means; a first baffle means surrounding the infrared detecting means and the above-mentioned combination; Claim 49 further comprising second baffle means surrounding the infrared and flame ionization detectors. A combined infrared and flame ionization detector as described. 58. In an infrared detection means for detecting multiple molecules of interest in a sample, The means (a) means for introducing the sample into at least the first and second supply means; (b) said first means for generating and exciting said plurality of molecules of interest; a first means for introducing a portion of said sample from a first supply means; When excited, several molecules emit a characteristic infrared radiation pattern, (c) a second means for exciting a first selection of said molecules of interest; a second means for introducing a portion of said sample from a second supply means of said sample; The first molecule, when excited, emits a characteristic infrared radiation pattern, (d) absorbing to remove unselected molecules of interest from the sample in the second supply means; adhesive means, (e) first and second radiation for detecting infrared radiation from said first and second means; detector means, each of said first and second radiation detectors detecting said infrared radiation; generates first and second electrical signals in response to Means consisting of things. 59. said detection is performed by a third supply means, of interest provided from said third supply means; a third means for exciting a certain second selected molecule; in response to the infrared radiation emitted by said second selected molecule of interest when a third infrared detector emitting three electrical signals as well as CO from said third supply means; 59. The infrared detecting means according to claim 58, further comprising means for removing.