JP2001235406A - Analyzer for gaseous organic compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an analyzer suitable for simply and rapidly performing on-line analysis of a gaseous organic compound in exhaust gas or atmosphere with high sensitivity. SOLUTION: Sample gas is taken by a probe 1 to be introduced into an adsorbing pipe 6 by a pump 9 and a harmful organic compound is adsorbed. Dust in the sample gas is trapped by means of a glass filter 5. The adsorbed harmful organic compound is desorbed by allowing an organic solvent 11 to flow through the adsorbing pipe and introduced into a mass analyzer 16 to be analyzed. Thereafter, dilute hydrochloric acid 19, methanol 22, toluene 25 and dry air 28 are successively introduced into the adsorbing pipe 6 and the glass filter 5 to clean them.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gaseous organic compound analyzer suitable for on-line analysis of harmful organic compounds such as dioxins and aromatics in exhaust gas discharged from an incinerator or in the air.

[0002]

[Prior Art] With increasing awareness of the environment and health,
There is an increasing need to control the concentration of gasified harmful organic compounds such as dioxins in incinerator exhaust gas and aromatics in the atmosphere within regulations. For this reason, there is a demand for an apparatus for quickly and accurately analyzing the above substances.

[0003] Looking at the situation of recent laws and regulations, regarding the use of dioxin, the Waste Management Law and the enforcement regulations have been revised and have been enforced since December 1, 1997. This regulation requires that each incinerator measure dioxin levels at least once a year and confirm that the dioxin levels meet the standards. A dioxin-related bill was deliberated at the Diet in July 1999 and is scheduled to go into effect in 2000.

With respect to organic compounds including aromatics, the revised Air Pollution Control Law came into effect on April 1, 1997, and three substances, benzene, trichloroethylene and tetrachloroethylene, were regulated. Reduction is requested. The regulation is expected to be extended to other hazardous substances.

[0005] An existing analysis method and apparatus will be described below.

[0006] 1. Analysis method and apparatus for dioxins (1) Standard method shown in Notification No. 234 of the Ministry of Health and Welfare "Method for calculating the concentration of dioxins" Insert a sampling probe into the incinerator flue, and filter cylindrical paper, impinger, resin, diethylene glycol. Dioxins are collected by the solution. The collected dioxins are extracted by solvent extraction and Soxhlet extraction. After the extract is mixed and concentrated, it is purified to obtain high-resolution G
Analyze by C / MS.

(2) "Method for measuring trace organic substances in exhaust gas from incinerator" disclosed in Japanese Patent Application Laid-Open No. 4-161849. Two adsorbing tubes are provided, exhaust gas is led to these tubes, and dioxins such as chlorobenzene and chlorophenol are introduced. After the alternative indicator substances are concentrated in the adsorption tube, the adsorption tube is set in another thermal desorption device to detect these substances. The concentration of dioxins is estimated from the correlation with the precursor of dioxins, which is an alternative indicator.

(3) "Recovery method and analysis method of chlorobenzenes and chlorophenols" disclosed in Japanese Patent Application Laid-Open No. Hei 8-266683. After a dioxin precursor such as chlorobenzene and chlorophenol is concentrated in an adsorption tube, , GC / MS, etc. In this method, the temperature of the dust remover is controlled to 50 to 200 ° C. in order to efficiently extract chlorobenzene and chlorophenol adsorbed to dust in the incinerator exhaust gas and to improve the quantitativeness.

[0009] 2. Methods and apparatuses for analyzing aromatics in the atmosphere include the following.

(1) Notification No. 4 of the Environment Agency (February 4, 1997)
Measurement method of benzene, trichloroethylene and tetrachloroethylene shown in (d) After collecting the air into a vacuum vessel called a canister, introducing an air sample from the canister into an adsorption tube filled with an adsorbent, and adsorbing the organic compound to be measured. To be concentrated. Alternatively, the air is directly introduced into the adsorption tube without using a canister, and the organic compound to be measured is adsorbed and concentrated on the adsorption tube. After concentrating the organic compound in the adsorption tube by the above method, the adsorption tube is heated to desorb the organic compound, introduced into the GC / MS, and analyzed.

[0011]

The present invention solves the following problems of the conventional method.

(1) Regarding the standard method shown in the Ministry of Health and Welfare Notification No. 234 “Method for calculating the concentration of dioxins” Regarding sampling, in the conventional method, exhaust gas is collected from an incinerator flue and then introduced into an analyzer. No online analysis methods have been taken. When sampling the sample, the operator takes the work of loading the sampling equipment into the incinerator flue, setting the sampling device, setting the sampling conditions, sampling, dismantling the sampling device, storing the sample, and unloading the sample and equipment. And one day. Equipment and labor costs are also high. In addition, sampling must be performed in three types: filter collection, resin collection, and liquid collection, which is complicated. Thus, there are problems in terms of workability, speed, and cost. Regarding the pretreatment, dioxins collected by a filter, a resin, and a liquid are extracted by liquid-liquid extraction or Soxhlet extraction, respectively, and then mixed and concentrated, followed by column purification and concentration. In this operation, a large amount of an organic solvent such as toluene, dichloromethane, and hexane is used. The treatment with these organic solvents has a large environmental burden. In addition, extraction, purification and concentration take several days, and labor and experiment costs are large. Thus, there are issues in terms of speed, cost, and impact on the environment. Regarding measurement, high resolution GC / M
The need for S makes the equipment very expensive. In addition, dioxin isomers are separated, and particularly highly toxic 2,3,7,8-TCDD, 2,3,7,8-TCDF
In order to separate from the other isomers, two types of columns are used, and the analysis time is about 4 hours in total. Thus, the above-mentioned measurement method has problems in terms of simplicity, quickness, and cost.

(2) "Method for measuring trace organic substances in exhaust gas from incinerator" disclosed in Japanese Patent Application Laid-Open No. 4-161849.
Regarding the need to set an adsorption tube by the experimenter, it is not yet an automatic online monitoring system because it requires manual operation.

(3) Regarding the “method of recovering and analyzing chlorobenzenes and chlorophenols” disclosed in Japanese Patent Application Laid-Open No. 8-266683, the sample introduced and concentrated in the adsorption tube is heated and desorbed and collected by the detector. You. However, part of the sample remains in the adsorption tube.
This residue affects the next analysis value, resulting in reduced reproducibility of the quantitative value. For this reason, removal of sample residue,
That is, it is essential to consider the regeneration of the adsorption tube. However, in this method, the regeneration of the adsorption tube is performed only by heating, and consideration for regeneration is insufficient. In order to remove the residue of the sample, it is desirable to make further efforts.

(4) Notification No. 4 of the Environment Agency (February 4, 1997)
Regarding the measurement method for benzene, trichloroethylene and tetrachloroethylene shown in (d), after collecting air samples in canisters and adsorption tubes, these sampling devices must be set in the analyzer, and it becomes a complete online analyzer. Not.

An object of the present invention is to provide a gaseous organic compound analyzer suitable for simple, rapid and highly sensitive on-line analysis of gaseous organic compounds in exhaust gas or air.

[0017]

SUMMARY OF THE INVENTION A feature of the present invention is that a probe for sampling a burning sample gas and an adsorption device connected to the probe for concentrating an organic compound in the sampled sample gas. And a device for flowing an organic solvent into the adsorption device for desorbing the organic compounds concentrated in the adsorption device, and a mass spectrometer for analyzing the desorbed organic compounds.

[0018]

FIG. 1 shows one embodiment of a gaseous organic compound analyzer according to the present invention. The apparatus of this embodiment includes a sampling section 100, a sample introduction section 110 connected to the sampling section, a detection section 120 connected to the sample introduction section, and a valve and a pump connected to these sections, A control unit 130 for controlling the entire apparatus such as measurement start / end, and a data processing unit 140 for operating the analyzer and processing and outputting data.
It has.

The sampling section 100 has a sampling probe 1 inserted into an incinerator flue or set at an air sampling place, and a thermostat 2 including a tube 3 'communicating with the sampling probe 1. Exhaust gas or air (hereinafter, “exhaust gas or air” is referred to as “sample gas”) is collected as a sample by the sampling probe 1. The tube 3 ′ through which the sample gas collected by the sampling probe 1 passes is 100
The temperature is kept between 200C and 200C. The sample gas collected by the sampling unit 100 is supplied to the sample introduction unit 110 via the valve 4.
Will be introduced. The sample introduction section 110 includes the adsorption tube 6. In the adsorption tube 6, sample concentration, solvent desorption, and washing are performed. In the sample introduction part 110, a concentrated organic compound is obtained.
The organic compound is supplied to the detection unit 1 connected to the sample introduction unit 110.
20 and analyzed. The detection unit 120 includes the mass spectrometer 15.

FIG. 2 shows a time chart of the online analysis operation through one analysis cycle in the apparatus of FIG.

The period T11 is an enrichment period, and during this period,
Valve 3 is opened, valves 17, 20, 23, 26 and 29 are closed, and valves 4, 8 and 13 switch to select channel a, and valve 14 selects channel b to drain 15 respectively. Can be Also, the pump 9 is turned on (on) and the pumps 12, 18, 21, 2
4 and 27 are deactivated (off). Therefore, the sample gas is sampled in the probe 1 at a constant flow rate, and the temperature of the tube is maintained at a constant temperature by the thermostat 2.
The gas is introduced into the adsorption tube 6 through the valve 3 '. A glass filter 5 is provided in front of the adsorption tube 6. Dust in the sample gas is trapped in the glass filter 5, and gaseous components pass through the glass filter 5 and fill the filler 7 filled in the adsorption tube 6. Is concentrated. The gaseous matter which has not been adsorbed by the adsorption tube 6 and has passed through it is discharged to the drain 10.
As the adsorbent 7, a resin such as Tenax, polyurethane, or XAD-2 is used. The sampling gas is about 1 to 50 L, and the sampling time is 1 minute to 50 minutes.

In the period T12 following the period T11, the organic solvent 1
1 is a sample desorption / measurement period. During period T12,
Valve 29 is opened and valves 17, 20, 23 and 26
Is closed and valves 13 and 14 are switched to select channel a and valves 4 and 8 are selected to select b. Also,
When the pump 12 is in the operating state (ON), the pumps 18, 21,
24, 27 and 9 are deactivated (off). Thereby, the organic solvent 11 is introduced into the adsorption tube 6.
Hexane, acetone, toluene or the like is used as the organic solvent 11. The amount of the organic solvent 11 to be introduced is about 100 mL. The sample concentrated in the adsorbent 7 is desorbed from the adsorbent 7 by the organic solvent 11. Of course, if there is a sample gas adsorbed on the glass filter 5, it is desorbed by the organic solvent, and the desorbed sample is transferred to the mass spectrometer 16 together with the organic solvent. As the best example of the mass spectrometer 16, a liquid chromatograph / mass spectrometer (LC / MS)
Is used. In this case, the total amount of the desorbed sample and the introduced organic solvent is used as a measurement sample.

A period T13 following the period T12 is a cleaning period. Period 13 includes four periods T131, T132, and T1.
33 and T134. During period T13, valve 3,
4 and 8 are kept the same as during period T12, valves 13 and 14 are both switched to select flow path b, and pump 9 is deactivated (off).

In this state, during the period T131, the valve 17
Is opened to operate the pump 18 (ON), the valve 20 is opened and the pump 21 is operated (ON) during the period T132, and the valve 23 is opened and the pump 24 operates during the period T133. State (on) and period T1
During the period 34, the valve 26 is opened and the pump 27 is operated (ON). Therefore, during the period T131, the diluted hydrochloric acid 19 of about 0.1 to 1N is flowed through the valve 17 using the pump 18 through the adsorption tube 6 and the glass filter 5, thereby dissolving the dust adsorbed on the glass filter 5. Removed. During the subsequent period T132, methanol 22 is flowed through the valve 20 using the pump 21 into the adsorption tube 6 and the glass filter 5, whereby the dilute hydrochloric acid accumulated in the adsorption tube 6 is replaced with methanol. Further, during the subsequent period T133, toluene, nonane, or decane 25 is flowed through the valve 23 using the pump 24, whereby contaminants are removed from the adsorbent 7 and the glass filter 5. Finally, period T13
4, dry air 28 is supplied to a valve 26 using a pump 27.
Through this, the organic solvent remaining due to the above-mentioned organic solvent washing is dried and removed from the adsorbent 7 and the glass filter 5 and regenerated. Thus, the cleaning of the adsorption tube 6 and the glass filter 5 is completed.

The on-line analysis operation during one analysis cycle has been described above.
Can be repeated at ~ 50 minute intervals.

The mass spectrometer 16 may be a gas chromatograph / mass spectrometer (GC / MS). In this case, the desorbed sample and the introduced organic solvent are split, and about 100 μL is used as a measurement sample.

According to the embodiment of the present invention, there is provided a gaseous organic compound analyzing apparatus suitable for on-line analysis of exhaust gas or gaseous organic compounds in the atmosphere in a simple, quick and highly sensitive manner.

[0028]

According to the present invention, there is provided a gaseous organic compound analyzer suitable for on-line analysis of exhaust gas or gaseous organic compounds in the atmosphere simply, quickly and with high sensitivity.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a gaseous organic compound analyzer showing one embodiment according to the present invention.

FIG. 2 is a diagram showing a time chart of an online analysis operation through one analysis cycle.

[Explanation of symbols]

1 ... sampling probe, 2 ... constant temperature bath, 3,
17, 20, 23, 26 and 29 ... valve, 3 '
... Tubes, 4, 8, 13, and 14 ... Valves (three-way valves), 5 ... Glass filters, 6 ...
Adsorption tube, 7, ... adsorbent, 9, 12, 18, 21, 24
And 27 ... pump, 10 and 15 ... drain, 11 ... organic solvent, 16 ... mass spectrometer, 19
... Dilute hydrochloric acid, 22 ... Methanol, 25 ... Toluene, 28 ... Dry air, 100 ... Sampling unit, 110 ... Sample introduction unit, 120 ... Detection unit, 1
30: control unit; 140: data processing unit.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G01N 27/62 B01D 53/34 120D

Claims (3)

[Claims] 1. A probe for sampling a calcined sample gas, an adsorption device connected to the probe for concentrating an organic compound in the sampled sample gas, and an organic compound concentrated in the adsorption device. A gaseous organic compound analyzer including a device for flowing an organic solvent into the adsorption device for desorbing compounds, and a mass spectrometer for analyzing the desorbed organic compounds. 2. The gaseous organic compound analyzer according to claim 1, further comprising a glass filter provided in association with the adsorption device and trapping dust in the sampled sample gas. 3. The gaseous organic compound analyzer according to claim 1 or 2, further comprising a cleaning device for cleaning the adsorption device for regeneration.