JPH04155239A - Monodispersal aerosol generator used for infrared spectroscopy - Google Patents

Abstract

PURPOSE: To realize a direct interface between a liquid chromatograph and a particle collector, and an infrared or a Raman spectrometer by supplying a liquid jet flow into a specific space and dispersing the liquid jet flow by a speed gas. CONSTITUTION: A liquid flowing out from a chromatograph column is fed by means of a pump 10 through lines 11, 13, a filter 16 and a line 17 and jetted into a monodispersive aerosol generator 18. It is then entrained by a high speed jet flow of inert gas from a thin tube 19 into a space 20 and diluted with a gas from a line 21 in order to evaporate a volatile solvent. Subsequently, it is passed through pressure reducing chambers 28, 29 coupled through an outlet pipe 26 with pumps 30, 31 in order to remove the dispersion gas and the solvent. A beam of aerosol dispersed with a sample substance can be collected as a small spot by a collecting plate 50 or a particle beam is led to a cell 52 and irradiated with an infrared beam 55 to produce an infrared spectrum which can be introduced to a mass spectrometer M. Alternatively, a solvent is introduced by means of the pump 10 and a sample can be injected using a syringe 15.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention was filed on June 22, 1984, and is currently 19 years old.
It was filed on March 19, 1986 as a partial continuation of Patent Application Specification Letter No. 623,711, which is Patent No. 4.629.487 issued on December 16, 1986, and is currently filed in August 1988. Patent No. 4.762.905 issued on September 9th
Monodisperse aerosol generator and interface structure for forming an aerosol beam and introducing it into an infrared or Raman spectrometer Regarding.

BACKGROUND OF THE INVENTION Monodisperse aerosol generators have been used as part-aerosol standards for reference, as sources for uniform particle injection for internal combustion snowmaking, and for flame and plasma atomic spectroscopy (e.g. atomic emission, atomic Monodisperse aerosol generators, however, have another utility alongside interface structures insofar as they are used as liquid introduction sources in liquid chromatographs (luminescence and atomic fluorescence spectroscopy). as an interface between a particle collection device or an infrared or Raman spectrometer, or as a means of introducing a solution into the device, or for direct introduction of a sample liquid into the interface without the use of a liquid chromatograph. A preferred interface structure according to the present invention is one that accepts a monodisperse aerosol, desolventizes it, and forms a solute aerosol beam that is introduced into a particle collection device or an infrared or Raman spectrometer in high purity. .

The device is intended to provide an aerosol particle source with a narrow particle size distribution and a high degree of efficiency. It can generate aerosols from a wide range of liquids with variable physical properties. These liquids include water and solutions of water-soluble substances, organic solvents and solutions of organic solvent-soluble substances, and the like.

The device produces a stable aerosol that, once formed, exhibits little tendency to condense and form agglomerates of particles;
Controlled evaporation can be used to partially or completely remove the solvent. The size of the aerosol droplets can be controlled by simple means.

This device is capable of producing an even and reproducible droplet concentration in the gas stream over long periods of time.

Similarly, it can be produced in droplets with sizes typically selected from a wide range of diameters from 5 to 200 μm.

Liquid chromatography, particularly modern high-performance liquid chromatography, provides powerful tools for separating complex mixtures of organic or inorganic species into their constituent components. Such compounds are concentration unstable or non-volatile under normal gas chromatography conditions. Many organic compounds, including those of biological importance, and most ionic and inorganic compounds fall into this category.

Infrared and Raman spectroscopy is a widely used technique to identify compounds and measure their concentrations in gases, numerous liquids, and solids.
Perry era, 22-31°Perry era, (196
3rd year 4th edition) Ko.

In liquid chromatography, a stream of solvent containing a mixture of chemical species in droplet form is passed under high pressure through a chromatographic column. The column is designed to separate a mixture into its constituent components by differences in retention time thereon.

The various constituents then emerge from the column as distinct bands in the solvent stream, separated in time. Liquid chromatography thus provides an ideal device for introducing a single species separated from an initial complex mixture into infrared or Raman spectroscopic form.

In order for the species emerging from the column to be introduced into a particle collection device or an infrared or Raman spectrometer, it is desirable to partially or completely remove the solvent from the dissolved species; serves the purpose of limiting the species that are collected on or that interact with the infrared radiation;
The presence of extraneous chemical species that collect on the collection surface or interact with the infrared light results in a hybrid and poorly characterized infrared or Raman spectrum. This type of infrared or Raman spectra generally has half its value for the identification of unknown compounds.

SUMMARY OF THE INVENTION One object of the present invention is to provide a means for collecting small samples of material as microspots on a moving collection surface, such as a rotating disk or a linear collection cylinder.

This trace spot can be directly matched to produce an infrared or Raman spectrum of the composition of the chromatographic effluent in real time. Alternatively, the collection surface can be removed from the system and the trace spot can be directly matched to create an infrared or Raman spectrum of the composition of the chromatographic effluent. It is also possible to test outside the system (i.e. off-line).

Another object of the invention is to provide a means for directly interacting a small sample of material in the form of a particle beam with an infrared beam in a specially designed cell. The infrared beam interacts with the particle beam, producing an infrared or Raman spectrum by direct particle/radiation interaction.

Yet another object of the present invention is to provide a means for introducing a particle beam present in a specially designed infrared beam interaction cell into a mass spectrometer. The infrared or Raman spectrometer/mass spectrometer acts as a combination system, providing inspection with the results of the infrared spectrometer and also acting as an additional sample elemental spectrum generator.

Another additional object of the present invention is to combine particles such that the particle beam present in a specially designed infrared beam interaction cell is collected as a small sample of material as a trace spot on a moving collection surface. The object of the present invention is to provide a means for a type infrared or Raman spectrometer/particle collection system. This record can be examined external to the system by infrared or Raman spectroscopy, or can be stored for later examination.

In particular, the preferred objectives of the invention are: (1) to enable a direct and simple interface between a liquid chromatograph and a particle collection device or an infrared or Raman spectrometer; (2) a liquid Providing efficient transport of species between a chromatograph and a particle collector or infrared or Raman spectrometer: (3) Any conventional ionization modality typically used for gas chromatography/infrared spectroscopy; (4) enabling the use of a wide variety of solvents, including solvents and solvent mixtures commonly used in standard, reversed-phase and ion-exchange liquid chromatography, such as alcohols, (5) The desolvated species are collected as a highly pure trace spot on a collection surface or in the infrared beam of a conventional infrared or Raman spectrometer. (6) Produce sufficiently highly concentrated species in the liquid chromatography effluent by solvent removal that they can be introduced directly into the interaction cell without the need for off-line analyte collection; Enabling Raman spectroscopy to: (7) enable reliable and routine operation: (8) provide precise, quantitative analysis of chemical species over at least the two-digit infrared range. thing.

Traditional methods for the direct generation of homogeneous aerosols from liquid vapors were carried out on the principle of applying regular disturbances to a cylindrical jet of liquid. This disturbance was applied axially or longitudinally to the jet as it emerged from a uniform circular nozzle. This disturbance was provided by an electromechanical device such as a piezoelectric crystal or loudspeaker coil driven by a radio frequency II source.

The orifices used were laser drilled steel or platinum disks or finely perforated stainless steel or glass capillaries.

In general, outfit! The minimum droplet required for is approximately 10P for circular disks and 40F for capillary devices. A typical disk device is Berglund and Liu
[Berglund.

R,N,, Liu, B, Y, H,Env, S
ci, & Technology.

7.147 (19731 Reference 1. The liquid passes under pressure through the disc orifice and emerges as a jet that is regularly disturbed by vibrations from a piezoelectric crystal. This piezoelectric crystal is The generator is driven at a selected frequency. Stable, uniform aerosol production is only possible over a limited range of liquid flow rates and vibration frequencies for each specific orifice size. The initial aerosol stream is dispersed by concentric gas jets, diluted by additional air, electrically neutralized by a radioactive source, and only then emerges from the span.

Typical tubular devices are Lindblad and 5chneid
er device [Lindblad, N.R.
5chneider, J.M.

J, Sci, Instrum,, 42.635
f196s)], here the liquid comes out of a stainless steel capillary tube and undergoes lateral disturbance from a piezoelectric crystal under high frequency oscillation and collapses into a uniform stream of droplets. - The droplet consistency produced by a one-side capillary type device is lower compared to that produced by a disk device, so no diluent gas is used to prevent agglomeration.

Other devices typically used for aerosol production and suitable for use with a wide range of solvents and solutions are pneumatic atomizers, fritted disk atomizers, and rotating disk atomizers. Devices based on ultrasonic aerosol generation using focused beam devices are also available.

Many approaches have been attempted to interface infrared or Raman spectroscopy with liquid chromatography. However, all other instruments that attempt to combine liquid chromatography with infrared or Raman spectroscopy cannot be used with high water content solvents;
Also, online operation with high water content solvents is not possible and requires offline collection techniques to obtain useful infrared or Raman spectra.For example, two prior art techniques must be investigated offline. , the sample does not contain any water and the solvent must be removed before solute analysis by spectral subtraction or evaporation.

Fritted disk atomizers are another atomizer that produces fine, uniformly sized aerosols. [
L, R, Layo+ann, F, E, Lich
Te.

Analytical Chemistry, 54.638 (19112, 11). In this device, a liquid passes over the surface of an array of thin tubes or porous fritted disks through which gas exits. Gas-liquid interactions generate aerosols. Instrument constraints for combination with chromatography include significant memory effects resulting in peak broadening and loss of resolution, and low liquid flow rates typically (less than 0.1d/win).

In the first method, the sample coming out of the liquid chromatography is atomized through a nebulizer and the solvent is
The zero-order solute, with 90% evaporation, was deposited onto a suitable substrate, such as a conventional KBr collection plate or a rotating reflective surface, for off-line infrared analysis. However, if the solvent contained water, the remaining water had to be removed, typically by heating, since water dissolves the KBr substrate, and any other solvent remaining in the sample had to be removed. It appeared as a solvent absorption band on infrared analysis.

Therefore, in order to obtain reliable results, it was necessary to remove substantially all of the carrier solvent before subjecting the sample to infrared analysis [Biemann, K., J.G.
agel, r isocratic
Continuous Infrared Spectroscopy of Cl and Gradient Elution Reversed Phase Liquid Chromatography Separations J, 59 AnalChem.
1266 (1987)].

In the second method, the sample coming out of the liquid chromatography was dropped into a collection cup or bank of collection cups filled with KBr. The solvent is generally evaporated from the sample by heating, and the analysis is subject to inherent diffuse reflection. This method has the same drawbacks as the first method: it must be done offline, all water must be removed,
Also, the presence of solvent can mask the spectrum and compromise the results. Moreover, heating the sample can alter the sample and lead to erroneous infrared analysis results [Griffiths, P.

et al. “Combination of Chromatography and FT-IR Spectroscopy J 58 Anal, Chen+, 1
349 Af No. 13 November 1986) j.

In gas chromatography/Fourier transform infrared spectroscopy systems, the sample is heated to 200°C to 300°C within the chromatograph. As the effluent leaves the chromatography, or after deposition onto a coolant-cooled surface, the zero-order deposition surface from which spectra can be collected is placed under an infrared beam for spectrum generation.

(Means for Solving the Problems) The present invention achieves at least two distinctive advantages using an aerosol generating device which will be described in detail below.

I will provide a. First of all, there is no need to heat or cool the sample, thus eliminating the possibility of the compound decomposing under very hot conditions. Second, there are far more compounds that cannot be analyzed by gas chromatography, such as non-volatile or thermally labile compounds, but can be analyzed by liquid chromatography.

The present invention overcomes these drawbacks and provides several additional advantages in continuous online infrared or Raman spectroscopy of liquid chromatography components using organic or aqueous solvents. First, the present invention allows on-line analysis of each component by analysis of particles collected on a moving surface or by direct action of a solute particle stream and an infrared beam. Second, the present invention allows solute analysis to be performed from solutions of any solvent, including high water content, without the need for heating to remove the solvent. Third,
The particle beam can be collected onto a suitable collection surface, such as KBr, immediately upon exiting the interface according to the invention, without risk of damage to the surface.

Regarding the monodisperse aerosol generator itself, no relevant prior art is known.

Figure 1 (FIG, 1) and Figure 2 (FIG.

2) of a liquid chromatography system showing embodiments of the invention forming an interface for use in direct injection or infrared beam/particle beam direct interaction into a liquid chromatography or particle collection system, respectively. A relatively pulsation-free pump (10) directs the effluent eluted from the chromatographic column (not shown) into a line (11) in which an optional multi-port sample valve (12) can be interposed. In a combined pump system, sample injection is not used, but a device to reduce the flow rate through the outlet line (13) may be necessary. For this purpose, a portion of the effluent can be discarded or directed through a line to a suitable collector and the diversion can be adjusted. If the sample is directly injected, the sample is introduced by means of a syringe (15).

In any case, the solution is prepared using a monodisperse aerosol generator (1
8) before passing through line (17) at (16). Although "monodisperse" refers to a single aerosol droplet or particle size, the term is used herein to refer to droplets or particles having a very narrow size range. The meaning of this should become clearer from FIG. 5, which compares a typical monodisperse aerosol in this sense with a polydisperse aerosol. The polydisperse aerosol shown in FIG. 5 was generated from a Perkin-E1mer cross-flow pneumatic nebulizer, whereas the monodisperse aerosol was generated from a 6 mm orifice as described here. It was generated based on the present invention using. Figure 5 (F
The measurements on which IG, 5) were based are the Fraunhofer diffraction tFraunho(e
r diffraction).

As explained in more detail below, the monodisperse aerosol is entrained in a high velocity gas jet originating from the capillary (19) and directed into a confined space (20) for the purpose of desolvation. This aerosol is suitably diluted with sheath gas entering from line (21) in an amount sufficient to maintain the desolvation chamber space (20) at substantially atmospheric pressure. By using near atmospheric pressure within the chamber (20),
The dequenching process is significantly enhanced and the monodisperse aerosol droplets or particles are almost completely depleted of solvent;
By the time the aerosol reaches the exit orifice (22) it may be in the form of a solvent-depleted solute.

Dispersion and sheathing gases are preferably supplied from suitable sources (
23), such as argon or helium. Its flow on the line (21) and into the capillary (19)! can be adjusted by respective flow regulators (24) and (25).

The chamber (20) typically has a diameter of 40 mm and a length of approximately 30 cm. The outlet v (26) may be a 1.5 inch stainless steel tube equipped with a suitable shut-off valve (27) to isolate the relatively high pressure chamber (20) from the vacuum region.

This vacuum area corresponds to the pumps (3o) and (31), respectively.
) is shown as consisting of two chambers (28) and (29) connected to one another. Typically, the pump (30) evacuates the chamber (28) at a flow rate of about 300 (2/min) to maintain the chamber (28) at a pressure in the range of 2-20 TOrr, whereas the pump (31) The chamber (29) is evacuated approximately 1501/11 in to maintain the pressure in the chamber (29) in the range of 0.01 to 10 Torr.

The nozzle end (32) of the tube (26) is precisely aligned with the conical end (33) of the first skimming cone skimmer (34).

The separation between (32) and (33) is typically about 1 to
6 particle collection mode (FIG.
, t) with a second cone skimmer (36) and a rotating collection plate (50) and support disc (51).
The separation distance between the infrared radiation/particle interaction mode (FIG.
2)), the nozzle end (35) and the outlet pipe (37
) between the flat ends (36) of 5-15 cm
is within the range of

The inner diameter of the nozzle (32) is O, 5 ma+, while the inner diameter of the two gaps (33) and (36) and the nozzle (35
) had an inner diameter of 1.0 mm, optimal results were obtained, as well as using an inner diameter of 0.5 m for all except the gap (33), which had an inner diameter of 1.0 mm.

In this mode of operation, a constant solvent flow rate is provided to the monodisperse aerosol generator (18) using a low pulse liquid pump (10). The monodisperse generator generates a finely dispersed solvent aerosol and sends it along with the dispersion gas into the desolvation chamber (20). In the desolvation chamber, the zero-order dispersion gas and solvent vapor mixture, in which most of the solvent has evaporated, passes sequentially into a first vacuum chamber (28), where a portion of the dispersion gas and solvent vapor mixture is removed. is removed by a vacuum pump (30).

The remainder of the dispersion gas and solvent vapor mixture is pumped through a vacuum pump (3
1) with a combined vacuum/collection plate chamber (2)
9) is removed within.

, the sample is introduced into the system using a syringe (15). The sample may be a pure liquid or may consist of a solution of a solid or liquid in a suitable solvent; the syringe may be a multiport valve, a septum injection system, or a high performance liquid chromatography system. In general, a small amount of sample*4 (typically 5 to xoOu) is introduced, which typically contains a few micrograms (+4) or It is thought that it contains several nanograms (ng). Monodisperse occurrence i
The aerosol generated by t now passes into a dewetting medium chamber and into a first vacuum/skimmer chamber that skims the particle beam from the gas stream and concentrates the particle beam. However, if the sample is present in the solvent stream, a highly dispersed aerosol of the sample material remains after hot medium evaporation. The particle beam then passes into a second chamber where the pressure is further reduced and the particles have a diameter approximately equal to the diameter of the gap in the momentum separator (choice of appropriate gap diameter and gap shape). The sample is collected on the collection plate as a small spot (typically 01-2.0 mm depending on the size). This spot may be directly matched for real-time infrared or Raman spectra of the chromatogram, or the ultrasound generated through the gap in the interface may be examined off-line with an infrared or Raman spectrometer by removing the collection surface. The separation of the particle beam from the gas stream is effective because the expansion imparts sufficient momentum to the aerosol particles so that they are hardly affected by the pump in the two chambers (28), (29). .

b High Liquid Chromatography Mode The operation of the high performance liquid chromatography interface is very similar to that of the direct injection device described above. The only major difference is that the sample may contain a mixture of compounds in this case, and these compounds must be fed to a chromatographic column (not shown) placed between the injection valve and the aerosol generator. By passing through it, it is separated into individual compounds.

2./I mode The operation of the infrared radiation/particle interface (IR/PI) mode in direct injection mode and high performance liquid chromatography mode is similar to the operation of the interface in direct injection mode and particle collection mode in high performance liquid chromatography mode. The major difference is that here, after leaving the desolvation chamber, the sample passes through two vacuum chambers (28), (29) and an exit tube (37). This means that it passes through the cell (52) and enters the cell (52). Inside this cell, an infrared beam (
55) uses two mirrors (
53), (54). An infrared spectrum is then generated by direct particle/radiation interaction. This mode does not require any particle collection and allows rapid production of infrared spectral data.

The operation of a combined mode infrared spectrometer/mass spectrometer (IR/MS) system is very similar to that of the IR/PI mode. The only major difference is the outlet pipe extension (137)
The mass spectrometer M is equipped with an infrared beam interaction cell (52
) in a dual spectrometer system, such as one connected to a

4. Line ゛  / 1 Acquisition The operation of a combined mode infrared spectrometer/particle collection (IR/PC) combination system is very similar to that of the IR/PI mode, with only one major The difference lies in the addition of a particle collection system connected to the infrared beam cell (52) by an outlet tube extension (137). The particle collection plate (50) can be inspected off-line or saved for inspection at a later date.

FIG. 3 shows a preferred nebulizer or monodisperse aerosol generator according to the invention.

As shown, a housing of the generator is provided for housing the nebulizer and has a glass tube connection (22) for connection to the desolvation chamber (first
FIG. 1), the atomizer structure is fitted with a cap (152) installed within a retaining gasket (154) within the body (151) and screwed onto the body (151) as shown. The line (17), consisting of a hollow tube (142) held in place, enters the body (151) through a retaining gasket (155) and is held in place by a cap (153). The entire body structure includes a gasket [144] between the cap (152) and (153) and the support column (143).
It is further connected to a monodisperse aerosol generator (18). ? The liquid is pumped through the aforementioned line (17) so that the line emits a steady jet from the tip of the tube (142).

FIG. 4 shows an interchangeable embodiment of the nebulizer or monodisperse aerosol generator. As shown, the nebulizer structure is both inside the tube (217) and inside the tube (217). ) is positioned coaxially with the holding tube (24
3) and a hollow tube (242) supported thereon, the wetting liquid is pumped through the line (217) and the tube (242)
This line (217) provides a steady jet from the tip of the tube (242) which mixes with the gas jet exiting from 19). In this embodiment, the gas jet in tube (219) is a self-aligning device for tube (242) in tube (219)! It acts as.

The diameter of the nozzle orifice can be between about 2 and about 100 pv, but preferably ranges from about 9 μm to about 20 μm, with a cylindrical collapse, as shown as A in Figure 6 CFIG, 6). It is controlled with respect to its speed so that it receives

Gradually higher velocities are depicted in B and C showing tortuous disintegration and atomization, respectively.

The cylindrical or monodisperse collapse of A is Rayleigh
gh) disintegration, producing droplets or particles of approximately uniform size and spacing; Note that the diameter of the droplet is approximately twice the diameter of the orifice. - radially, for the preferred orifice diameter, a stable jet with Rayleigh collapse is approximately 3 mf
produced at a flow rate of less than f/min.

The tip of the glass atomizer is made from a thick-walled glass capillary tube with an outside diameter of 0.25 inches. One end of the tube is initially flame sealed, closing the tube in a conical shape. This end is then opened by grinding with a fine abrasive medium (eg, 400 grade silicon carbide paper) until an orifice of the appropriate diameter is created. The diameter of this orifice can be measured using a calibrated microscope.

The other end of the tube is shaped into a lip;
This is ground at its lower edge to form a watertight seal to the gasket placed within the threaded end of the 5 metal block. The tip of the sprayer is held in place with a retaining cap.

Maximum liquid supply to the device is 300Lb/in”
It is carried out with a pump capable of withstanding liquid flow rates in the range from O, Old d/+ain to 37/min at pressures of . This pump should likewise provide little pressure pulsation during operation; the standard pumps used are those suitable for high performance liquid chromatography.

The dispersion gas is introduced through a capillary tube (19) made of stainless steel or some other suitable rigid material. The dispersion gas tube is fixed between 3 and 10 mm above the tip of the glass orifice (142). Install it using a suitable alignment device.

The dispersion gas, controlled by suitable devices such as pressure controllers, needle valves and rotameter, flows through the dispersion gas capillary at a suitable flow rate to produce efficient dispersion of the aerosol. Gas flow rate is typically 0.5-2β
/min.

The aerosol produced by the device may be sampled by any suitable means, or the aerosol generator may be transferred into a desolvation chamber or to a sampling boat of another device by sealing the aerosol generator within the chamber. Good too. This first chamber is then used to ensure efficient transfer of the aerosol to subsequent devices.
These devices can be sealed.

(Effects of the invention) The main differences between this device and advance snowmaking as well as the resulting advantages are as follows: For the operation of the ill device (no external mechanical disturbance sources are required) .

(2) Since a very circular opening with a diameter of 2 pu is created, a slit can be easily made from a glass capillary tube.

(3) Secure! The diameter of the aerosol produced by is controlled by the diameter of the liquid orifice. The particle size of the aerosol is approximately 1.2 (9) of the orifice diameter. The exact relationship between aerosol diameter and orifice diameter depends on the compressibility of the liquid.

(4) Selection of aerosol diameter by changing orifices can be accomplished easily and quickly.

(5) The device operates very stably over long periods of time without the need for adjustment.

(6) The device operates highly reproducibly from day to day without the need to realign components or reoptimize parameters between each field.

(7) A variety of liquids can be used in the device, with the only requirement being to change the contents of the liquid tank to change the liquid to be converted to aerosol.

Both aqueous and organic solvents and mixtures of aqueous and organic solvents and mixtures of organic solvents can be used in the device.

(8) Any of the solvents or solvent mixtures mentioned in paragraph (7).
Among these, inorganic and organic samples can be dissolved at concentrations up to 1% by weight percentage of dissolved solids without causing blocking problems in the device.

(Even when using a 91KBr collection plate, 1
Any solvent can be used, including 0.00% water.

(10) Continuous online infrared or Raman spectral analysis can be performed without the need to remove the collection plate or interrupt the process for offline analysis.

(11) When used in place of or in conjunction with a light tube, the particle collection plate
It can be stored as a hard copy.

(12) The cylindrical gap design of the interface improves the efficiency of the solvent and carrier gas removal process by about 10 times compared to previous designs.

(13) To identify the spectra of the sample, the obtained spectra can be compared to computer-generated spectral standards.

(14) In general, a solvent-free particle beam has a diameter of 0
．． Having small dimensions of 1-2.0 mm, it is possible to collect more sample spots on the collection plate.

(15) Due to the lower pressure within the collection chamber, collection on the collection surface is improved by reducing the air boundary layer on its surface.

(16) Since the solvent water is removed very effectively, an alkali halide collection plate can be used without dissolving the alkali halide.

(17) The particle beam deposits small diameter sample spots on the alkali halide plate without the need to manually place the dry sample on the alkali halide plate.

゛ In order to prevent deterioration of the monodisperse aerosol production due to agglomeration and/or impact between the droplets, the dispersion preferably distributes the aerosol coaxially or at an angle, preferably 90°, to the axis of the stable jet. It can be seen that the angular dispersion should not be done near random or Rayleigh collapse points, and that the vacuum equipment separates the solvent vapor and the gaseous medium while separating the gaseous medium,
It can likewise be seen that solvent vapor and solvent-depleted solute are continuously ejected to form a monodisperse aerosol beam of solvent-depleted solute. This beam has high momentum and
It passes through the final gap and moves into the ion supply temperature. Similarly, it should be understood that the solvent-depleted solute beam is comprised of particles with a smaller flux than that of the aerosol originally produced, and includes a somewhat larger relative size distribution range.

It should also be noted that the present invention is utilized for two very distinctive purposes. (])
and (
2) As an interface between a flowing liquid stream and a particle collection device or Fourier transform infrared or near infrared Fourier transform Raman spectroscopy or Hadamard transform infrared spectroscopy or Hadamard transform near infrared Raman spectroscopy, this interface includes aerosol generation. Although equipment is included, the combination of physical processes to remove solvent from the droplets and concentrate the sand particles is also important to the performance of the interface.

In the present invention, an aerosol generation/desolvation device developed for use in mass spectrometry uses an infrared beam to dissociate the aerosol onto the collection device with very little beam spread and with high efficiency. The present invention also produces a stream of dry bi-dispersed particles that is collected or passed through a cell for interaction with an infrared beam to produce a mid-infrared spectrum analysis. It is also the only device known to be capable of on-line generation of Fourier transform Raman spectra or Agemard transform E-ray 1-line spectra or Hadamard transform Raman spectra from both polar and non-polar hot liquids.

[Brief explanation of drawings]

FIG. 1 (FIG. 1) is an explanatory diagram of the device of the present invention used as a particle collection system. FIG. 2 (FIG. 2) is an explanatory diagram connected to FIG. 1 used as a combined infrared spectrometer/mass spectrometer system. FIG. 3 (FIG. 3) is a cross-sectional view of the monodisperse aerosol generator of the present invention. FIG. 4 is a cross-sectional view of an interchangeable embodiment monodisperse aerosol generator using a coaxial gas/liquid injection system. FIG. 5 is a graph comparing monodisperse and polydisperse aerosols. FIG. 6 (FIG. 6) shows the cylindrical collapse according to the invention (A) compared to the tortuous collapse (B) and the atomization (C).
This is a country that shows FIG. 7 is a Fourier transform infrared spectrum using particle collection mode. 10...Pump 11...Line 12...
・Multi-port sample valve 13...Outlet line 15...Syringe 17...
・Line 18... Monodisperse aerosol generator 19... Thin tube 20... Restricted space 21... Line 22... Outlet orifice 23... Gas supply source 24.25... Flow rate adjustment Device 26...Outlet pipe 27...Shutoff valve 28.
29...Chamber 30.31...Pump 32...
- Nozzle end 33... Conical end 34... Cone gap 35... Nozzle end 36... Second cone gap 37... Outlet pipe 50... Collection plate 51...・Support disk 52...Cell 53.54
...Mirror 55...Infrared beam 137...
Extension outlet pipe 142...Hollow tube 143...Support column 144...Gasket 151...Body 152.153...Cap 154...Gasket 155...Retaining gasket 217.219.242 ... Tube 243... Engraving of drawing of holding tube FIG 4 Engraving of gall □ Particle size (cold) FIG 5 FIG G Wave number (c+a-'I FIG 7 Procedural amendment written format) August 10, 1990 Day

Claims (1)

Claims: (1) Nozzle means for ejecting a stable cylindrical jet of liquid, maintaining the velocity of the jet at a constant value such that random breakdown of the jet into droplets of approximately uniform size occurs; an aerosol generating device comprising supply means for supplying liquid to said nozzle means at a rate sufficient to cause said nozzle means and dispersion means for dispersing said droplets near the point of droplet formation. (2) An aerosol generator according to claim 1, characterized in that said dispersing means includes a high-velocity gas jet directed at an angle to the axis of said liquid jet. (3) The aerosol generating device according to claim (2), characterized in that said angle is approximately 90°. (4) The nozzle means has a diameter of 2 μm to about 100 μm.
Aerosol generating device according to claim 1, characterized in that it includes an ejection orifice with a diameter in the range of . (5) The dispersion means comprises a capillary and a gas supply source that supplies the dispersion gas to the capillary at a rate of about 1/2 liter to about 2 liters per minute.
The aerosol generator described in . (6) The supply means has a flow rate of about 0.01 ml/min. Approximately 3 ml/min. The aerosol generating device according to claim 5, characterized in that the liquid is supplied to the nozzle means at a rate of . (7) Aerosol generation means according to claim 6, characterized in that said capillary discharges the dispersion gas at a distance between 3 mm and 10 mm above the tip of said discharge orifice. (8) An aerosol generating device according to claim (4), characterized in that said nozzle means includes a capillary discharge orifice. (9) nozzle means for ejecting a stable cylindrical jet of a solution into a confined space, wherein such solution includes a relatively volatile solvent in which a relatively non-volatile solute is dissolved; supply means for supplying solution to said nozzle means at a rate sufficient to maintain the jet velocity at a value such that droplet formation occurs; a dispersing means for entraining the droplets, receiving at one end thereof and having a restricted outlet spaced a sufficient distance from said one end, before reaching said outlet; A desolvation chamber allowing volatilization and a gaseous medium at high velocity through said restricted outlet to form an aerosol beam of solvent-depleted solute with a narrow particle size distribution while separating the solvent vapor and gaseous medium. A system for producing an aerosol beam of solvent-depleted solute with a narrow particle size distribution, comprising a vacuum means for continuously ejecting the medium, solvent vapor, and solvent-depleted solute. (10) The desolvation chamber is maintained at approximately atmospheric pressure, and the vacuum means includes a vacuum chamber connected to the restricted outlet and maintains the vacuum chamber at a pressure of 2 to 20 Torr. System according to claim 9, characterized in that it comprises a vacuum pump that does. (11) a second vacuum chamber and a vacuum pump for maintaining this second vacuum chamber at a pressure of 0.01 to 10 Torr, and depletion of solvent from said first-mentioned vacuum chamber to said second vacuum chamber; 11. System according to claim 10, characterized in that it includes skimmer means for separating said beam of dissolved solute. (12) The system of claim (10), characterized in that the vacuum chamber includes a collection surface for collecting the solute particle beam. 13. The system of claim 12, wherein the collection surface is movable. 14. The system of claim 11, further comprising second skimmer means for separating a beam of solute particles from said second vacuum chamber into an infrared spectrometer cell. (15) The nozzle means has a diameter of 2 μm to about 100 μm.
System according to claim 9, characterized in that it includes a discharge orifice with a diameter in the range m. (16) The above-mentioned dispersion means includes a capillary and about 1/min.
Claim 15 characterized in that it comprises a gas supply supplying the dispersion gas to this capillary at a rate of from 2 l to approximately 2 l.
). (17) The supply means has a flow rate of about 0.01 ml/min.
Approximately 3 ml/min. 17. System according to claim 16, characterized in that the liquid is supplied to the nozzle means at a rate of . 18. The system of claim 17, wherein the capillary discharges the dispersion gas at a distance of 3 mm to 10 mm above the tip of the discharge orifice. (19) Means for producing a stable liquid jet having a velocity such that droplet collapse of the jet occurs without external perturbation, and said droplets in a high velocity flow of a gaseous medium to maintain their properties. A system for generating an aerosol, characterized in that it includes dispersion means for entraining. (20) a first chamber into which the entrained droplets are ejected, and expanding the gaseous medium with the entrained droplets into a low pressure chamber to form a concentrated aerosol beam; System according to claim 19, characterized in that it further comprises pressure reduction means for. (21) The first chamber is maintained at approximately atmospheric pressure, and the pressure reduction means includes a
System according to claim 20, characterized in that it includes a pump that maintains the pressure in the range of Torr. (21) another low pressure chamber connected to said low pressure chamber and second pressure reduction means for expanding said gaseous medium with entrained droplets into said another low pressure chamber; System according to claim 21, characterized in that it comprises: (23) The second pressure reducing means has a pressure of 0.01 to 10T.
23. System according to claim 22, characterized in that it includes a pump for maintaining another low pressure chamber at a pressure in the range of orr. (24) The method according to claim 19, characterized in that it includes multi-stage depressurization means for concentrating the gaseous medium with entrained droplets into a high momentum particle beam. System described. (25) A method of introducing a solute into an infrared or Raman spectrometer comprising: (a) providing a solution comprising a relatively volatile solvent and a relatively nonvolatile solute; (b) forming a narrow size distribution. (c) providing a dispersing gas; (d) dispersing the formed droplets with the gas; (e) entraining the aerosol within the gas and desolventizing the aerosol at near atmospheric pressure; (f) removing the gas to form a high momentum aerosol beam of solute particles with a narrow size distribution;
A method comprising the steps of: expanding the components of step (e) into a low pressure environment; and (g) directing said beam into an infrared or Raman spectrometer. (26) A method according to claim 25, characterized in that the beam is directed onto a collection surface within an infrared or Raman spectrometer. (27) The method according to claim 25, characterized in that the beam of infrared radiation interacts directly with the beam of solute particles. (28) A method according to claim 27, characterized in that the beam of solute particles is then directed onto a collection surface. (29) characterized in that the beam of solute particles is then directed from an infrared or Raman spectrometer to a mass spectrometer;
The method according to claim (25). (30) The method according to claim 25, characterized in that the solution is provided from the effluent of liquid chromatography. (31) In a system for introducing a solvent-depleted solute into an infrared or Raman spectrometer, the system comprises: (a) means for providing a solution containing a relatively volatile solvent and a relatively non-volatile solute; b) for producing a monodisperse aerosol from a solution by feeding the solution into a nozzle at a velocity sufficient to produce a stable jet of liquid with a velocity such that monodisperse droplet collapse of the jet occurs; (c) means for dispersion to entrain the droplets after the point of droplet formation in a high velocity stream of gas to preserve their monodispersity; (d) means for desorption to produce a solvent-depleted solute; (e) vacuum means for expanding said gas with entrained droplets into a low pressure environment while removing the gas to form a high momentum monodisperse aerosol beam of solute particles; (f) A system characterized in that it comprises means for directing said beam into an infrared or Raman spectrometer. 32. The system of claim 31, wherein the pressure reducing means includes a first vacuum chamber with a pressure in the range of 2 to 20 Torr. (33) The pressure reducing means further includes two vacuum chambers, and the second vacuum chamber has a pressure of 0.01 to 10
System according to claim 31, characterized in that it has a pressure in the range of Torr. (34) The system of claim (31), wherein the desolvation chamber is maintained at approximately atmospheric pressure. (35) characterized in that it further comprises a vacuum chamber for continuously discharging the gaseous medium and a vacuum pump for maintaining this vacuum chamber at a pressure in the range from 2 to 20 Torr. ). (36) further comprising a second vacuum chamber and a second vacuum pump that maintains the second vacuum chamber at a pressure within the range of 0.01 to 10 Torr;
The system according to claim (35). 37. The system of claim 31, further comprising a collection surface on which the beam of particles is directed. 38. The system of claim 31, further comprising means for directing a beam of particles from an infrared or Raman spectrometer into a mass spectrometer. 39. The monodisperse aerosol generator of claim 1, wherein said nozzle means includes a capillary discharge orifice positioned coaxially within said dispersion means. 40. The system of claim 10, further comprising an infrared or Raman spectrometer for collating a beam of monodisperse solute particles from the vacuum chamber. (41) An aerosol generating device comprising nozzle means for emitting a steady cylindrical jet of liquid, wherein such nozzle means includes a first capillary ejection orifice, such that the collapse of the jet into droplets of narrow size distribution occurs. supply means for supplying liquid to said first capillary discharge orifice at a rate sufficient to maintain the jet velocity at a constant value; and dispersion means for dispersing said droplets near the point of droplet formation. A device characterized by: (42) The aerosol generating device according to claim (41), characterized in that the dispersion means includes a high-velocity gas jet coaxial and directed in the same direction as the axis of the liquid jet. 43. The aerosol generating device of claim 42, wherein said nozzle means includes a second capillary discharge orifice for directing said high velocity gas jet. (44) The aerosol generation device of claim (43), wherein said second capillary discharge orifice is coaxial with said first capillary discharge orifice. (45) The first capillary discharge orifice is approximately 2 μm
Aerosol generating device according to claim 44, characterized in that it has a diameter in the range of about 100 μm. (46) The dispersion means has a flow rate of about 1/2 l/min. from about 2l/min. Aerosol generation device according to claim 41, characterized in that it includes a gas supply source for supplying dispersion gas to the dispersion means at a rate of . (47) The supply means is approximately 0.01 ml/min. Approximately 3 ml/min. The aerosol generating device according to claim 41, characterized in that the liquid is supplied to the nozzle at a speed of .