JPH1137986A - Automatic analyzer and method for chlorobenzenes - Google Patents

Abstract

(57) [Problem] To provide a compact automatic analyzer which can be used for analyzing chlorobenzenes as an alternative index of dioxins contained in incinerator exhaust gas or metal refining process exhaust gas. SOLUTION: This is an automatic analyzer for chlorobenzenes provided with at least a concentrator 3, a cold trap injector 4, a separation device 5, a detector 6, and a data processing device 8, if necessary, wherein the cold trap injector 4 has a capillary tube. An automatic analyzer for chlorobenzenes having a polysiloxane surface treatment on the inner surface. An automatic analysis method in which the cold trap injector 4 is cooled at a temperature higher than -80C by liquefied carbon dioxide gas. An automatic analysis method in which a gas chromatograph equipped with a capillary column as a separation column is used as the separation device 5, and the initial setting temperature of a thermostat of the gas chromatograph is set to 40 ° C. or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for automatically analyzing organic compounds contained in combustion exhaust gas from incinerated general waste and industrial waste or gas discharged from a metal refining process. .

[0002]

2. Description of the Related Art In general, when incinerating various kinds of wastes, extremely intoxicating dioxins may be generated from an incinerator. In addition, when metal refining is performed in an electric furnace or the like, scraps often have coatings and resin-laminated materials on their surfaces, and when these are thermally decomposed and polycondensed, dioxins are also generated. There is.

[0003] The concentration of dioxins contained in these exhaust gases is 1 even when dioxin and its homologues and dibenzofuran and its homologues are all included.
Since it is about ng / Nm ³ or less, it is impossible to directly measure with current technology. As described in the Journal of the Air Pollution Society, Vol. 28, No. 5, p. 274 (1993), chlorobenzenes have a high degree of correlation with dioxins. There is a method of calculating and obtaining the concentration of a class. Therefore, it is extremely important to accurately determine chlorobenzenes or chlorophenols in exhaust gas.

A technique for automatically analyzing chlorobenzenes and chlorophenols (hereinafter, collectively referred to as chlorobenzenes) in exhaust gas is described in Bulletin of the Institute of Environmental Studies, Yokohama National University, Vol. 18, pp. 1-8 (1992), JP-A-5-321796. Is described in Japanese Patent Application Publication No. Further, Japanese Patent Application Laid-Open No.
It is also described in the official gazette.

[0005] These techniques are based on a glass trap for removing water vapor contained in exhaust gas, a concentration tube filled with a resin adsorbent, a heater capable of heating the same, and a gas chromatograph device. It is. Concentration operation is necessary because chlorobenzenes are low in concentration, and gas chromatograph equipment separates nitrogen, oxygen, chlorine, hydrogen chloride, and various organic compounds contained in exhaust gas in addition to chlorobenzenes. Needed for quantification.

[0006] According to these techniques, first, the exhaust gas is drawn by a pump downstream of the concentrating tube to remove water vapor by a glass trap, and passes through the concentrating tube. At this time, the chlorobenzenes in the exhaust gas are adsorbed by the resin adsorbent because the temperature of the concentration tube has not been particularly increased.

Next, the temperature of the concentrating tube is raised to 270 ° C., and at the same time, the line is switched so that the carrier gas of the gas chromatograph is passed through the concentrating tube and sent to the gas chromatograph. Thereby, the adsorbed chlorobenzenes are desorbed and quantified by a gas chromatograph.

Incidentally, the concentration of chlorobenzenes in the exhaust gas at this time is 4-34 μg of monochlorobenzene.
/ Nm ³ , 4-65 μg / m with 1,4-dichlorobenzene /
Nm ^3, 3~10μg / Nm ³ in hexachlorobenzene,
27-186 µg / Nm with 2,4-dichlorophenol
^3, 4 to 4 in 2,3,4,6-tetra-chlorophenol
It is reported as 5 μg / Nm ³ .

On the other hand, the aforementioned Journal of the Air Pollution Society, Vol. 28, No. 5,
No. 274 (1993), in order to further increase the concentration to improve the analysis sensitivity and accuracy, a cold-stage apparatus is used as a two-stage concentration apparatus between the concentration tube and the gas chromatograph apparatus. A trap injector is provided. This device has a thin tube (inner diameter 0.53 mm) generally called a capillary tube made of glass or the like, and further concentrates the measurement object concentrated by the concentration tube.

The method of using this cold trap injector is as follows. First, a capillary tube is cooled to -130.degree. C., and chlorobenzenes extruded by a carrier gas from a condensing tube heated to 250.degree. Gather. Thereafter, the capillary tube of the cold trap injector in which these substances have been recollected is rapidly heated to 250 ° C. and introduced into the gas chromatograph.

As described above, by re-collecting in the capillary tube, the concentrated substance can be released in a short time. This is because the interior is not filled with the resin adsorbent, so that the entire volume is reduced and the heat conduction during heating is improved, so that rapid heating can be performed. Therefore, since chlorobenzenes can be introduced into a gas chromatograph with a narrow bandwidth, high-sensitivity and high-accuracy analysis becomes possible.

[0012] Japanese Patent Application Laid-Open No. H4-161849 discloses a similar description, in which chlorobenzenes adsorbed on an adsorption and filling tube are heated and desorbed, trapped in a capillary tube cooled with liquid nitrogen, and then rapidly cooled to 250 ° C. Heated to the mass spectrometer.

[0013]

However, among the above-mentioned prior arts, the method using only a concentrating tube can achieve sufficient concentration when the concentration of chlorobenzenes is low, such as in the latest waste gas from incinerators. Therefore, subsequent analysis by a gas chromatograph or the like becomes impossible.

In order to analyze a trace amount of chlorobenzenes, it is necessary to further concentrate by a cold trap injector. However, also in this case, in the related art, it was necessary to cool to about -130 ° C., and the use of liquid nitrogen was inevitable. In order to use liquid nitrogen,
A special spraying device and its storage container (Dewar or pressurized container) are required. These liquid nitrogen devices are usually larger than the main body of the automatic analyzer assuming continuous measurement, and in the case of a pressurized container, an installation place for a high-pressure container is particularly necessary. This hindered downsizing.

The present invention has been made to solve these problems, and can be used for analysis of chlorobenzenes as an alternative index of dioxins contained in incinerator exhaust gas or metal refining process exhaust gas. And,
An object of the present invention is to provide an automatic analyzer in which the size of the device is reduced.

[0016]

The invention according to claim 1 is an automatic analyzer for chlorobenzenes provided with at least a concentrator, a cold trap injector, a separator, a detector and, if necessary, a data processor. The cold trap injector is an automatic analyzer for chlorobenzenes, which has a capillary tube, and the inner surface of the capillary tube is subjected to a surface treatment using polysiloxane.

The concentrator is a device for adsorbing chlorobenzenes from the gas to be measured with an adsorbent, and may be of a type using an ordinary resin adsorbent.

The cold trap injector is a device having a capillary tube, and an object to be measured inside the tube can be cooled by a cooling medium from the outer surface of the tube, condensed, and adhered to the inner surface. Also, capillary tubes,
That is, since it is a capillary tube and has a very small diameter, it can be rapidly heated by a heater. As a result, the chlorobenzenes are quickly desorbed and introduced into the gas chromatograph.

A major feature of the present invention is that the inner surface of the capillary tube is surface-treated using polysiloxane. Here, the surface treatment means that the polysiloxane adheres to the inner surface of the tube, and does not need to be completely covered. As the polysiloxane, an ordinary polysiloxane to which a methyl group is added or a product in which a part of a methyl group is substituted with a phenyl group, a propyl group, or the like may be used.

In the liquid phase, these polysiloxanes exert a coercive force on chlorobenzenes by interaction, and chlorobenzenes condense and adhere. A cooling temperature of about -70 ° C. is sufficient for this, and chlorobenzenes can be collected again on the inner surface of the capillary tube. Also, other substances (compounds) contained in the exhaust gas, especially hydrogen chloride, chlorine and sulfur compounds, do not suffer extreme damage. As a result, a dedicated liquid nitrogen spraying device and its storage container (Dewar bottle or pressurized container)
Is unnecessary, and the size of the automatic analyzer can be reduced. In addition, it is preferable to install the capillary tube itself in the gas chromatograph device because the heating device can also be used.

The separation device only needs to be able to separate chlorobenzenes from other compounds, and an ordinary column chromatograph, for example, a gas chromatograph can be used.
As the detector, a normal detector provided in a gas chromatograph device or the like may be used.

Although the data processing device is not an essential component, it is convenient to have a data processing device because data analysis can be easily and easily realized by a computer.

According to a second aspect of the present invention, when cooling the cold trap injector using the automatic analyzer according to the first aspect, the cold trap injector is cooled at a temperature higher than -80 ° C. by liquefied carbon dioxide gas. Is an automatic analysis method.

Since the present invention uses the automatic analyzer according to the first aspect, a cooling temperature of about -70 ° C. is sufficient. As a result, the work related to the handling of the liquid nitrogen spraying device and its storage container (Dewar bottle or pressurized container) and the filling work of liquid nitrogen are not required, and the labor of the analysis work can be saved.

According to a third aspect of the present invention, in the automatic analyzer according to the first aspect, a gas chromatograph device having a capillary column as a separation column is used as the separation device, and the initial set temperature of the thermostat of the gas chromatograph device is set to 40. ° C
The following is an automatic analysis method for chlorobenzenes characterized by performing analysis as follows.

In the present invention, since the initial setting temperature of the thermostat of the gas chromatograph is set to a low temperature, the interaction between the liquid phase of the separation column and chlorobenzenes becomes strong, and the injected (introduced) chlorobenzenes are removed from the separation column. It is held at the entry part. Therefore, the bandwidth of the injection narrowed by the cold trap injector can be further narrowed. Further, when the analysis method of the present invention is used, the cooling temperature of the cold trap injector is sufficient at about room temperature.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In carrying out the present invention, a gas to be measured such as exhaust gas is subjected to a pretreatment by a dust remover and a dehumidifier as required. First, if dust or mist is contained in the exhaust gas, the measurement may be hindered or the measuring device may be soiled. Therefore, a dust remover is provided to remove dust and mist from the exhaust gas supplied to the measuring device. A general dust filter may be used for this dust collector, but it is necessary to control the temperature so that chlorobenzenes are not adsorbed. That is, the entire dust remover is placed in a constant temperature bath, or a heater is wound, for example, at 100 to 300 ° C., preferably 12 ° C.
0 to 160 ° C.

However, the dust remover can be omitted when the amount of dust and mist in the exhaust gas is very small, such as in the piping downstream of the bag filter in the municipal solid waste incineration process, that is, when the exhaust gas is sufficiently clean.

The concentrator according to the present invention comprises a glass or metal tube (concentration tube) filled with a resin adsorbent such as Tenax (trade name), and a condensing tube having a heater or the like.
A device capable of raising the temperature to about 0 ° C. is provided. In addition, it has a pump and a gas flow meter capable of sucking the exhaust gas after the above-described dust removal and dehumidification, and a mechanism capable of sending a carrier gas for a gas chromatograph used as a separator through a concentrating tube to a gas chromatograph. Just do it.

It is more preferable to have a function of holding a mechanism for blowing low-temperature air, carbon dioxide gas, or the like to the concentrating tube, and have a function of controlling the temperature in the operation of adsorbing components (chlorobenzenes) in exhaust gas.

The dehumidifier (main body) is made of a glass container (trap), a ceramic container, a metal container,
Any material, such as a graphite container, may be used as long as it is not damaged by components in the exhaust gas. Further, when temperature control, that is, cooling is performed, the dehumidifying efficiency is further improved, and stable dehumidifying can be achieved.

The dehumidifier also has a very small amount of water introduced into the gas chromatograph when the moisture in the exhaust gas is extremely small or when the concentration of the exhaust gas is extremely small, so that there is no risk of damaging the separation column. You can omit it.

The cold trap injector provided between the concentrator and the gas chromatograph has a capillary tube having a diameter of about 0.5 mm and has a function of cooling and rapid heating. Cooling and rapid heating can be realized by a cooling mechanism of about -70 ° C by spraying liquefied carbon dioxide gas or the like and a rapid heating mechanism of about 300 ° C by a large-capacity heater or the like.

The material of the capillary tube may be made of simple glass, but is desirably equivalent to a silica capillary column used in a gas chromatograph. On the inner surface of this capillary tube, 100% dimethyl-polysiloxane, 5% phenyl-95% methyl-polysiloxane, 7%
% Cyanopropyl-7% phenyl-86% dimethyl-polysiloxane and the like. Further, it is desirable to coat the outer surface of the capillary tube with polyimide from the viewpoint of improving the strength of the capillary tube.

As a separation apparatus, a gas chromatograph apparatus is used as long as it can be equipped with an ordinary capillary column and has a function of raising the temperature to about 300 ° C.
The detector includes a mass spectrometer, a flame ionization detector,
An electron capture detector or the like can be used.

The data processing function receives the signal output from the detector and converts it into the amount of chlorobenzenes. If the correlation between chlorobenzenes and dioxins is determined in advance, it can be further converted to the amount of dioxins.

The control of the entire exhaust gas automatic analyzer at the time of automatic exhaust gas analysis can be performed by a sequencer.
It is more preferable to use the data processing device described above.

[0038]

【Example】

(Embodiment 1) FIG. 1 is a block diagram showing an embodiment of an automatic exhaust gas analyzer for automatically analyzing chlorobenzenes in exhaust gas. In the figure, 1 is a dust remover, 2 is a dehumidifier, 3
Is a concentrator, 4 is a cold trap injector, 5 is a separator (gas chromatograph), 6 is a detector (mass spectrometer), 7 is a sequencer, 8 is a data processor, 10
Is a pump, 11 is a flow meter, 21 is a gas (for analysis), 22
Is gas (exhaust), 31 to 35 are pipes (for analysis gas), 6
0 indicates a cylinder (helium), 62 to 63 indicate pipes (for helium), 80 indicates a cylinder (for carbon dioxide), and 81 to 82 indicate pipes (for carbon dioxide).

As shown in FIG. 1, this automatic analyzer
Dust remover 1 with built-in filter, electronically cooled dehumidifier 2,
A concentrator 3, a cold trap injector 4, a gas chromatograph 5, a mass spectrometer 6, a sequencer 7 for controlling the entire analyzer, and a measured chromatogram, which can cool and heat a glass tube filled with a resin adsorbent. The main component is a data processor 8 for calculating chlorobenzenes from the data.

The dust remover 1 was a sample filter 33S6 manufactured by GL Sciences Co., Ltd., and the whole was put in a thermostat and kept at 140 ° C. As the dehumidifier 2, an electronic cooling type dehumidifier DH-109 manufactured by Komatsu Electronics Co., Ltd. was used.

As the concentrator 3, a 6 mm diameter glass tube is filled with a resin adsorbent (trade name: Tenax), a heater is wound, and a liquefied carbon dioxide gas is blown from a carbon dioxide gas cylinder 80 to a temperature control of 0 to 300 ° C. Prototype that can be used.

Similarly, the cold trap injector 4 has a diameter of 0.5 mm and an inner surface of 5% phenyl-95% methyl-
A capillary tube treated with polysiloxane is heated,
And what can be made into -70-300 degreeC by spraying liquefied carbon dioxide gas was trial manufactured and used. Further, the helium gas from the helium gas cylinder 60, that is, the carrier gas of the gas chromatograph is passed through the capillary tube and sent to the gas chromatograph.

The gas chromatograph 5 is HP5890
The type and mass spectrometer used were HP5970 type, and the data processor used was a gas chromatograph-mass spectrometer manufactured by Yokogawa Hewlett-Packard Co., Ltd. Also,
The column used was a micropolar column manufactured by GL Sciences Corporation.

The sequencer 7 is a prototype, a rotary pump is used as a pump 10 for sucking exhaust gas through a concentrator, and a flow meter 1 for measuring the flow rate of exhaust gas.
As 1, an integrating type was used. Further, although not described in detail, valves were appropriately attached to the pipes connecting the devices (normal valves, three-way valves, and six-way valves) so that the following operations could be performed.

The automatic analysis was performed according to the following procedure.
The gas chromatograph device 5 (including the mass spectrometer 6)
Helium as a carrier gas is supplied from the helium cylinder 60 through the line 63 to be in a standby state. Exhaust gas 21 from a state-of-the-art refuse incinerator was sucked in by a pump 10 at 10 liters through lines 31 to 33.

At this time, the electronic dehumidifier 2 was kept at 0 ° C., and the concentrator 3 was kept at 25 ° C. Therefore, the cold trap injector 4 is controlled to −40 ° C. by blowing carbon dioxide gas from the carbon dioxide gas cylinder 80 through the line 82, and at the same time, helium is sent from the helium gas cylinder 60 to the concentrator 3 through the line 62. The concentrator 3 is heated by a heater to 280
When the temperature starts to rise to ℃, the adsorbed chlorobenzenes
When the chlorophenols are desorbed and go to the cold trap injector 4 through the line 35, they are collected again.
At this time, the helium discharged from the cold trap injector 4 has entered the gas chromatograph device and has become carrier gas.

When the temperature of the concentrator 3 reached 280 ° C., helium was sent to the cold trap injector 4 through the line 63, and at the same time, the supply of helium in the line 62 was stopped, and the temperature of the cold trap injector 4 was raised. The temperature was raised to 280 ° C., and as a result, chlorobenzenes and chlorophenols were sent to the gas chromatograph device 5 and the mass spectrometer 6, and the analysis values were automatically output from the data processing device 8.

FIG. 2 is a view showing the results of analysis of chlorobenzenes and chlorophenols measured by a gas chromatograph. The measurement method is SIM (Selcted I
on Monitor) method. As described above, a gas chromatogram having peaks of chlorobenzenes and chlorophenols is obtained.

Other measurements were performed several times, and in each case, similar results were obtained. Thus, the inner surface of the capillary tube surface treated with polysiloxane is not damaged by the other substances contained in the waste gas from the incinerator, and the re-concentration of the waste gas containing various substances (compounds) is improved. The surface treatment with polysiloxane was found to be effective.

(Example 2) The material of the capillary tube of the cold trap injector 4 was changed to 50% phenyl-50% methyl-polysiloxane, and the temperature at the time of re-collection was set to 20 ° C. A similar test was performed using the same apparatus as in Example 1. Analytical values of chlorobenzenes and chlorophenols were automatically output from the data processor 8 as in Example 1.

Example 3 An experiment was conducted using the same apparatus as in Example 1 except that the concentrator 3 and the cold trap injector 4 were partially modified. That is, cooling of these devices by liquefied carbon dioxide gas was stopped, and instead of removing the liquefied carbon dioxide gas cylinder, the devices could be cooled by room temperature air from a compressor already provided for driving the valves of the automatic analyzer.

The concentrator 3 used was a 3 mm diameter glass tube filled with a resin adsorbent at a length of 30 mm. As the cold trap injector 4, a capillary tube having an inner surface material of 50% phenyl-50% methyl-polysiloxane was used.

For automatic analysis, the concentrator 3 is controlled to near room temperature with room temperature air from a compressor to perform adsorption / concentration, and the cold trap injector 4
Except that reconcentration was performed while controlling the temperature around room temperature.
The procedure and operation were the same as in Example 1.

As the separation column, a chemically bonded fused silica capillary column (non-polar column) having 100% methyl-polysiloxane as a liquid phase on the inner surface and a polyimide resin coated on the outer surface was used. At the start of the reconcentration, the initial setting temperature of the thermostat of the gas chromatograph apparatus was set to 40 ° C., and after the reconcentration was completed, the temperature of the thermostat was raised and the analysis was performed after the injection of the chlorobenzenes was completed.

FIG. 3 shows the obtained gas chromatogram.
Shown in As in Examples 1 and 2, chromatograms having peaks of chlorobenzenes and chlorophenols were obtained.

Comparative Example 1 A similar experiment was performed using the same apparatus as in Example 1 except that the material of the capillary tube of the cold trap injector 4 was Pyrex glass (the inner surface of the tube was not particularly treated). Conditions). However, the analysis values of chlorobenzenes and chlorophenols were not output from the data processor 8, and the peaks corresponding to the chlorobenzenes and chlorophenols could not be confirmed from the gas chromatogram.

(Comparative Example 2) A similar experiment was conducted using the same apparatus as in Example 3 except that the initial setting temperature of the thermostat of the gas chromatograph apparatus was set to 80 ° C. The resulting gas chromatogram is shown in FIG. However, no peaks corresponding to chlorobenzenes and chlorophenols were found.

As described above, in the cold trap injector, the chlorobenzenes and chlorophenols cannot be collected at the collection temperature of -70 ° C. in the capillary tube (the glass tube having an untreated inner surface) of the comparative example. On the other hand, by using a capillary tube whose inner surface is treated with polysiloxane as in Examples 1 and 2, it is possible to sufficiently collect at a temperature (-70 to room temperature) at which cooling with liquefied carbon dioxide gas is possible. The analysis of chlorobenzenes by a gas chromatograph becomes possible.

Further, by setting the initial set temperature of the thermostat of the gas chromatograph apparatus to 40 ° C. or less, the re-collection temperature of the cold trap injector can be increased, and chlorobenzenes can be re-collected even by cooling with room temperature air. This makes it possible to analyze chlorobenzenes using a gas chromatograph.

[0060]

According to the present invention, chlorobenzenes can be recollected at a temperature of about -70 ° C. by subjecting the inner surface of the capillary tube of the cold trap injector to a surface treatment using polysiloxane. As a result, there is no need to use liquid nitrogen, and a dedicated liquid nitrogen spray device and its storage container are not required, and the automatic analyzer can be made compact.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of an automatic exhaust gas analyzer of the present invention.

FIG. 2 is a view showing the results of analysis of chlorobenzenes and chlorophenols measured by the apparatus of Example 1.

FIG. 3 is a view showing an analysis result of chlorobenzenes and chlorophenols obtained in Example 3.

FIG. 4 is a diagram showing the results obtained in Comparative Example 2.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 dust remover 2 dehumidifier 3 concentrator 4 cold trap injector 5 separator (gas chromatograph) 6 detector (mass spectrometer) 7 sequencer 8 data processor 10 pump 11 flow meter 21 gas (for analysis) 22 gas (exhaust) 31-35 Piping (for analysis gas) 60 Bomb (helium) 62-63 Piping (for helium) 80 Bomb (liquefied carbon dioxide) 81-82 Piping (for liquefied carbon dioxide) P1 Chlorobenzene P2 Chlorophenol P3 Dichlorobenzene P4 Trichlorobenzene

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Hiromi Sakurada 1-1, Minamiwata-cho, Kawasaki-ku, Kawasaki

Claims (3)

[Claims] 1. An automatic analyzer for chlorobenzenes comprising at least a concentrator, a cold trap injector, a separator, a detector and, if necessary, a data processor, wherein the cold trap injector has a capillary tube. An automatic analyzer for chlorobenzenes, wherein the inner surface of a capillary tube is subjected to a surface treatment using polysiloxane. 2. Using the automatic analyzer according to claim 1,
An automatic method for analyzing chlorobenzenes, wherein the cold trap injector is cooled at a temperature higher than -80C by liquefied carbon dioxide gas. 3. The automatic analyzer according to claim 1, wherein
A method for automatically analyzing chlorobenzenes, wherein a gas chromatograph equipped with a capillary column as a separation column is used as a separation device, and the analysis is performed by setting an initial temperature of a thermostat of the gas chromatograph at 40 ° C. or lower.