JPH08101102A - Sampling device for sample in environment - Google Patents

Abstract

PURPOSE: To facilitate continued or intermittent monitoring of the measuring of the atmospheric environment. CONSTITUTION: A packed tower 2 is furnished in which atmosphere sample and an absorbent liquid are allowed to flow countercurrently and the intended component of the atmosphere sample is absorbed into the absorbent liquid, wherein the atmosphere sample is continuously supplied by a pump 12 to the tower 2 at a constant rate of flow from an atmosphere sample supply port 8, and the absorbent liquid is supplied by a constant flow pump 28 from an absorbent liquid reserver 22 at a constant rate of flow through an absorbent liquid supply hole 4 at the top of the tower 2. The intended component of the atmosphere sample is absorbed in the absorbent liquid, taken out from an absorbent liquid takeout hole 10 at the bottom of the tower 2, and supplied as the sample to an analyzing device 34.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sampling device for collecting a target component such as a harmful pollutant in the environment and using it as a sample for an analyzer. , An apparatus for using as a sample of an analyzer.

[0002]

2. Description of the Related Art As a collection and pretreatment method for collecting and concentrating a trace amount of harmful substances in the atmosphere, (1) canister collection and cooling concentration method, (2) filler such as Tenax GC (registered trademark) or activated carbon is used. Adsorption tube method using packed column, (3) impinger collection method for performing reaction collection and absorption collection, and (4) collection method using urethane foam and glass filter paper are performed. In these methods, the substances to be measured are limited, and they cannot be applied to a wide range of substances. Further, in environmental measurement, continuous monitoring is required for a long period of time, but for continuous monitoring, only a few devices that can be used in the methods (1) and (2) have been proposed.

In the environmental measurement, water quality analysis, drinking water analysis in the food field, and pharmaceutical analysis are important as well as the atmosphere. Pretreatment steps for concentrating and isolating sample components are required in those fields. Especially in environmental analysis, continuous or intermittently repeated continuous monitoring is required.

Trihalomethanes and volatile hydrocarbons in water,
When analyzing components, odors, odors, etc. in edible medicines and beverages, target components are selectively concentrated by a batch type purge-and-trap method. Purge and
In the trap method, a sample is put in a container having a constant volume, an inert gas is bubbled to vaporize a volatile component to be analyzed, and the component is collected and used as a sample for an analyzer.

[0005]

In atmospheric environment measurement, the above methods (1) to (4) have the following problems, respectively. The method (1) is difficult to collect continuously. If we dare to make continuous operation possible, the equipment becomes extremely complicated. The method (2) has a limit in the amount of collected gas, and a great deal of labor is required to study the condition setting. The method of (3) cannot collect continuously, and the amount of work of the measurer becomes large even if it is attempted to collect it as a prefectural bandit. The method of (4) is not suitable for collecting component types. Therefore, an object of the present invention is to provide a gas sampling device that facilitates continuous monitoring or intermittent and continuous monitoring in atmospheric environment measurement.

A gas chromatograph / mass spectrometer (GC / MS) or the like is used as an analyzer in analysis such as water quality analysis in which a liquid is used as a sample, but a target component in the sample water is vaporized by a purge and trap method. The sample thus obtained is diluted with an inert gas and is often a sample whose detection sensitivity is lower than that of the analyzer. Therefore, it is necessary to concentrate the sample collected in that way, but since the volume of the container is fixed in the conventional method, it is necessary to replace the container according to the sample concentration, and because it is a batch system, it is continuous. The problem is that such monitoring is impossible in principle. Further, since bubbling an inert gas into the sample water is not effective in purging, a large amount of the inert gas is required, and in that sense, the sample component is diluted.
Therefore, when a liquid sample is used as the sample, it is necessary to further simplify the mechanical operation when purging the target component in the sample and increase the gas-liquid contact area to enhance the purge efficiency.

[0007]

According to the present invention, in order to be able to perform atmospheric environment measurement continuously or continuously,
The target component is extracted with the absorption liquid, and if necessary, concentrated to prepare a sample for the analyzer. Preferably, the collection of the target component and the analysis are carried out in a consistent flow, and an absorption liquid corresponding to the target component is selected and used in order to separate and collect the target component.

The sampling device of the present invention has an absorption liquid supply port and an exhaust port at the upper end of the packed column, an atmospheric sample supply port and an absorption liquid extraction port at the lower end, and the atmosphere inside the packed column. A packed absorption tower that countercurrently flows the sample and the absorbing solution into the absorbing solution to absorb the target component in the atmospheric sample, and a pump is equipped with the atmosphere sucked from the atmosphere sampling port and continuously or intermittently repeated at a constant flow rate. The atmospheric sample supply mechanism that supplies air from the atmospheric sample supply port to the absorption tower and the absorbing liquid that absorbs the analysis target component in the atmospheric sample continuously at a constant flow rate or intermittently repeated in response to the supply of the atmospheric sample. The absorption liquid supply mechanism for supplying the absorption liquid from the absorption liquid supply port into the absorption tower is provided, and the absorption liquid taken out from the absorption liquid extraction port is supplied to the sample of the analyzer. Gas chromatographs (GC), GCs are the main analytical instruments used in atmospheric environment measurement.
/ MS, liquid chromatograph (LC), atomic absorption spectrophotometer (AA) and the like.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 schematically shows an embodiment. The absorption tower 1 is provided with a packed tower 2 in which the air sample and the absorption liquid are counter-currently caused to absorb the target component in the air sample into the absorption liquid. The absorption liquid supply port 4 and the exhaust port 6 are provided at the upper end of the packed tower 2.
Is provided, and an atmospheric sample supply port 8 and an absorbing liquid extraction port 10 are provided at the lower end portion. 11 is equipped with a pump 12 and continuously or intermittently repeats the air sucked from the air sampling port 14 at a constant flow rate to fill the packed column 2 from the atmospheric sample supply port 8.
It is an atmospheric sample supply mechanism that supplies the inside. The air sampling port 14 of the air sample supply mechanism 11 is provided with a filter for removing solids such as dust in the air. 16 is a flow meter. Reference numeral 21 denotes an absorption liquid which is supplied from the absorption liquid supply port 4 into the packed tower 2 continuously or intermittently and repeatedly at a constant flow rate of the absorption liquid for absorbing the analysis target component in the air sample. It is a supply mechanism. The absorption liquid supply mechanism 21 stores the absorption liquid adjusted to a constant concentration in the absorption liquid reservoir 22, and supplies the absorption liquid at a constant flow rate from the absorption liquid supply port 4 at the upper end of the packed tower 2 by a constant flow pump 28. Reference numeral 30 is an opening / closing valve for the absorption liquid supply passage. In order to prepare the absorption liquid to be stored in the absorption liquid reservoir 24, the reservoir 22 is provided with a flow path 23 for supplying a high-concentration stock solution stored in a cool and dark place by a stock solution supply pump 24 as necessary, and a diluent solution by the pump 26. A supply channel 25 is provided.

The exhaust port 6 of the packed tower 2 is open to the atmosphere, but in order to prevent air pollution, a cooling collector 36 and an absorption pipe 38 are provided in the exhaust passage as an exhaust gas cleaning system as needed. It may be installed. In FIG. 1, the broken line represents the flow of the substance to be analyzed. The operation of each unit is controlled by a centralized system based on a computer.

Next, an example of collecting amines using this embodiment will be described. A ninhydrin solution is used as the absorption liquid. A high-concentration solution stored in a cool and dark place is supplied to the absorption liquid reservoir 22 by a pump 24 as needed, and at the same time, a dilution liquid is mixed from the pump 26 to prepare an absorption liquid and stored in the reservoir 22. The absorption liquid in the reservoir 22 is supplied from the upper end of the packed tower 2 by the constant flow pump 28,
The absorbing liquid that has entered flows down the surface of the packing material in the packed tower and flows down to the lower part by gravity. On the other hand, the atmosphere of the sample is sucked from the sampling port 14 by the pump 12, enters the packed column 2 from the lower part of the packed column 2 at a constant flow rate, moves to the upper part while being in contact with the absorbing liquid, and is discharged from the exhaust port 6. It

The amines in the air sample react with the ninhydrin in the absorption liquid in the packed tower 2 to be absorbed and become a ninhydrin derivative, and together with the absorption liquid, the lower absorption liquid outlet 1
Go out of the packed tower 2 from 0. The absorption liquid containing amine is directly used for high performance liquid chromatography (HPLC) and ultraviolet (U)
V) or a fluorescence spectrophotometer or other analyzer 34 may be directly analyzed. If necessary, the concentrating device 32 may be used to concentrate the amine component, and then the amine component may be conducted to the analyzer 34 for analysis.

When an instantaneous value is required in the environmental analysis,
The absorbent taken out from the absorbent outlet 10 may be sequentially analyzed. If an integrated value over a long period of time is required, once a certain time of the absorbent taken out from the absorbent outlet 10 is temporarily stored in a container. After storing, it may be analyzed by HPLC or UV analyzer.

When a gas chromatograph is used as an analyzer, hydrochloric acid is used as an absorption liquid, amines are absorbed by the hydrochloric acid, and a caustic soda solution and acetic anhydride (or trifluoroacetic anhydride) are added at the position of the concentrator 32. After derivatization, it is suitable to analyze by gas chromatography. Atmospheric organic acids, phenols, non-volatile substances,
When measuring an inorganic harmful gas or the like, it can be dealt with by replacing the absorbing liquid with one that absorbs those target components.

FIG. 2 shows GC / MS of the target component in the liquid sample.
1 shows an example of a sampling device for making a sample for measurement by an analyzer such as. In FIG. 2 (A), the absorption tower 50 is filled with a filler 52 as shown in an enlarged view in FIG. 2 (B), and the sample specimen flows down from the gap of the filler and from below. Inert gas rises as purge gas. Reference numeral 54 is a tower wall of the absorption tower, 56 is a flow of purge gas, and 58 is a sample specimen.

Partition plates 60 and 62 having holes are attached to the lower part and the upper part of the absorption tower 50, and the space between the partition plates 60 and 62 is filled with a filler 52. At the lower end and the upper end in the absorption tower 50, a space where no filler is present is formed. A purge gas passage 64 for supplying an inert gas as a purge gas is provided in the lower space of the absorption tower 50. Reference numeral 66 is a solenoid valve that controls the supply of purge gas. A discharge port 68 for discharging the waste liquid sample is provided at the lower end of the absorption tower 50.

At the upper end of the absorption tower 50, a sample specimen is pumped 7
0 is connected to the sample supply flow path, and the upper end portion is connected to the purge gas outlet 72 for taking out the purge gas in which the component to be analyzed is purged, and the extraction flow path 74 connected to the purge gas outlet 72 is guided to the trap device 76. There is. The analysis target component trapped by the trap device is guided to the analysis device for analysis.

The operation of the apparatus of FIG. 2 will be described. The absorption tower 5
The sample specimen is caused to flow from the upper end of 0 by the pump 70, and the purge gas is caused to flow from the lower end of the absorption tower 50. Volatile substances in the sample specimen are carried by the purge gas to the outside of the absorption tower through the outlet 72, and are trapped by the trap device 76 such as a cooling trap.

In the case of continuous purging, the sample specimen is supplied to the absorption tower 50 at a constant rate in this state. In the case of batch operation, a cleaning water supply port for supplying cleaning water is provided at the upper end of the absorption tower 50. After supplying the purge gas from the lower end of the absorption tower 50 and supplying a predetermined amount of the sample specimen from the upper end of the absorption tower 50, the supply of the sample specimen is once stopped. Then, after the purging of the analysis component is completed, the supply of the purge gas is also stopped once. After that, washing water is flown into the absorption tower 50 to wash the inside, and then purge gas is passed again to completely remove volatile components inside. Then, the process returns to the supply of the sample specimen from the upper end and the supply of the purge gas from the lower end.

In purging using the counter-current type absorption tower 50 as shown in FIG. 2, the efficiency of expelling volatile components is determined by the ratio of the purge gas flow rate G to the sample sample liquid matrix flow rate L. When the distribution coefficient K of a certain component satisfies the condition represented by the following equation (1), the component is efficiently purged and trapped. K <L / G (1)

On the other hand, under the condition that the following expression (2) is satisfied, the component flows out from the outlet 68 together with the sample specimen. K> L / G (2) The partition coefficient K is related to the enthalpy ΔH, and since K becomes large in the high boiling point component, the condition of the above formula (2) is satisfied, which is unnecessary in the GC / MS analysis. It is convenient for removing high boiling components. Further, the purge speed with the purge gas increases as KG / L increases.

FIG. 3 shows an example of an environment monitoring device using the device of FIG. (A) and (B) show the portion for collecting the sample, and the pump 70 for supplying the sample specimen is
In (A), an on-off valve 82 is installed in the line 80 where the product flows in the factory.
Can be installed via. Further, when the sample water is collected from the river 84, the sample is directly taken from the river by the pump 70.

The sampling device of FIG. 2 including the absorption tower 50 is
As shown in FIG. 3C, the purge gas flow path 74 from the purge gas outlet 72 is guided to the trap device 76, and the trapped target sample component is analyzed by the analyzer 86 such as GC / MS. Reference numeral 88 controls the sample supply flow rate and the purge gas flow rate of this sampling device, controls the operation of the trap device 76, controls the operation of the analysis device 86, and also processes the data obtained by the analysis device 86. It is a control / data processing and management system.

The following effects can be achieved by using the apparatus shown in FIG. Since the purge gas is brought into contact with the sample specimen by the countercurrent method, the applicable range for the change in the specimen concentration is dramatically expanded, and continuous purging becomes possible. Also,
The process is simplified and the apparatus is simplified as a whole, including the washing operation after the analysis. Since an absorption tower is used, the purging efficiency is significantly increased due to the dramatic expansion of the gas-liquid contact area and the thinning of the sample liquid specimen. In addition, the generation of droplets caused by conventional bubbling is suppressed, and line contamination is suppressed. In this way, continuous monitoring is enabled, problems such as pollution are solved, and it becomes easy to construct an online monitoring system as a flow system.

A mode of handling a liquid sample as a sample is as follows. The inside is filled with a filler, the upper end has a sample supply port for supplying a liquid sample sample, the purge gas outlet for taking out the analysis target component of the volatile components expelled by the purge gas, and the purge gas for supplying the purge gas to the lower end. An absorption tower having a supply port and a discharge port for discharging the waste liquid after contacting the purge gas, a sample supply mechanism for supplying a sample sample at a constant flow rate from the sample supply port at the upper end of the absorption column into the absorption column, and the absorption column A purge gas supply means for supplying an inert gas at a constant flow rate from the purge gas supply port at the lower end of the absorption tower, and a trap device connected to the purge gas outlet at the upper end of the absorption tower for trapping the component to be analyzed displaced by the purge gas. A sampling device characterized by being provided.

[0026]

According to the sampling device for atmospheric monitoring of the present invention,
Since an absorption tower is used and the atmospheric sample and the absorbing liquid are brought into contact with each other by countercurrent flow inside the absorption tower, the collection efficiency is improved by the principle equivalent to the multi-stage collection, and also due to splash dispersion. Sample loss can be prevented. If the absorption liquid is continuously sent to the absorption tower, the absorption efficiency will be stable and it will be possible to cope with deterioration of the absorption liquid due to other chemical species. Absorption selectivity is also possible by changing the type of absorption liquid, and it is possible to cope with a wide range of pollutants. By performing stable collection continuously, continuous analysis becomes possible. Since it is absorbed by a liquid, it is easy to make it continuous, and it becomes easy to support the introduction system of analytical equipment. With regard to unstable substances, it is expected that effects such as higher measurement accuracy can be expected by utilizing the reaction with the reagent used for the absorption liquid and changing to stable derivatives.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment.

2A and 2B are diagrams showing an apparatus for collecting volatile components in a liquid sample, FIG. 2A is a schematic configuration diagram, and FIG. 2B is a cross-sectional view showing an enlarged inside of an absorption tower at a portion b of FIG. is there.

3 is a diagram showing an application example of an environment monitoring device using the device of FIG. 2, (A) is a schematic plan view showing a sample collecting part from a factory line, and (B) is a sample collecting part from a river. FIG. 2C is a schematic diagram showing a monitoring device using this sampling device.

[Explanation of symbols]

 1 Packed absorption tower 2 Packed tower 4 Absorption liquid supply port 6 Exhaust port 8 Air sample supply port 10 Absorption liquid extraction port 11 Air sample supply mechanism 12 Pump 14 Air sampling port 21 Absorption liquid supply mechanism 22 Absorption liquid reservoir 24, 26 Pump

Claims (1)

[Claims] 1. An absorption liquid supply port and an exhaust port are provided at the upper end of a packed column, and an atmospheric sample supply port and an absorption liquid take-out port are provided at the lower end, and an atmospheric sample and an absorption liquid are stored in the packed column. The above-mentioned atmospheric sample supply is performed by continuously or intermittently repeating a packed absorption tower that countercurrently flows into the absorption liquid to absorb the target component of the atmospheric sample and a pump, and the atmosphere sucked from the atmospheric sampling port at a constant flow rate. Atmospheric sample supply mechanism that supplies from the mouth into the absorption tower and the absorbing liquid that absorbs the analysis target component in the atmospheric sample continuously at a constant flow rate or intermittently repeated in response to the supply of the atmospheric sample An absorption liquid supply mechanism for supplying the absorption liquid from the supply port into the absorption tower, and the absorption liquid taken out from the absorption liquid extraction port is used as a sample of an analyzer.