JP2003028848A - Method and apparatus for continuous analysis of cations and anions - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method in which concentrated cation and anion components are continuously analyzed in a cation analytical part and an anion analytical part by using a pipe constitution wherein the same sample in which an ion component in the air collected by using a diffusion scrubber has been dissolved is continuously fed to a cation concentration column and an anion concentration column and to provide an analyzer which is used in the method. SOLUTION: Only the cation component from among ion components sampled from the air is concentrated in a concentration column 13, and the anion component is concentrated in a concentration column 23. The concentrated cation and anion components are eluted from a separation column 14 and a separation column 24 by eluants which are optimum for the cation and anion components. Concentrations of the eluted cation and anion components are measured by respective electric conductivity meters, and the cations and the anions in the same sample can be continuously analyzed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for analyzing an extremely small amount of gas and an analyzer used therefor, and more particularly to an analysis method for continuously measuring a cation component and an anion component at a high speed and a method used for the same. Analysis device.

[0002]

2. Description of the Related Art In the next-generation semiconductor manufacturing process,
There are an increasing number of cases where trace amounts of gaseous pollutants remaining in clean rooms cause semiconductor manufacturing defects. In order to stabilize the mass production process, the target substance is removed with a dust / chemical filter.However, a contaminant measurement accident or chemical filter breakthrough occurs in the manufacturing process. It is necessary to automate and continuously measure and monitor.

An example of a conventional continuous cation and anion analysis method is described in JP-A-2-223857. As shown in FIG. 5, in this conventional cation and anion continuous analysis method, a column for cation and a column for anion are connected in series to shift the appearance of the cation component and the anion component with time. By using the phase eluent, the cation component and the anion component are measured with the same conductivity meter.

However, the above-mentioned conventional system has the following problems.

The problem is that continuous analysis is difficult with a mobile phase eluent when both the cation component and the anion component are separated for a long time.

The reason for this is that the combination of pH, concentration and flow rate of the mobile phase eluent causes a time lag between the cation component and the anion component. This is because the components cannot be separated, and if the concentration of the mobile phase eluent is lowered, the components having a long separation time cannot be separated.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method capable of measuring a cation component and an anion component at the same measurement point at the same time.

Another object of the present invention is to continuously supply the sample containing the cation component and the anion component collected by the sampling unit to the cation concentration unit and the anion concentration unit to obtain the sample amount. Is to reduce.

Another object of the present invention is to shorten the analysis time by continuously measuring the cation component and the anion component.

[0010]

SUMMARY OF THE INVENTION Therefore, the present invention is for a cation having a sampling section for collecting gas components in the atmosphere and a function for concentrating cation components in the sample collected by the sampling section. A concentrating section, an anion concentrating section having a function of concentrating an anion component in the sample, a cation analyzing section for analyzing and measuring the cation component concentrated in the cation concentrating section, and the anion It comprises an anion analysis unit for analyzing and measuring anion components concentrated in the ion concentration unit, and a control unit for automatically and integrally controlling each unit, and the cation concentration unit and the anion unit. The method for continuous cation and anion analysis is characterized in that the ion concentrating unit is performed using an analyzer connected in series by a pipe during sampling operation.

The present invention also provides a sampling unit for collecting gas components in the atmosphere, a cation concentration unit having a function of concentrating cation components in the sample collected by the sampling unit, and the sample. A concentration unit for anions having a function of concentrating an anion component therein, a cation analysis unit for analyzing and measuring the cation components concentrated in the cation concentration unit, and a concentration in the anion concentration unit And a control unit for automatically and integrally controlling each unit, and the cation concentration unit and the anion concentration unit are sampled. It is a continuous cation and anion analyzer characterized by being connected in series by pipes during operation.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The apparatus used in the method for continuous analysis of cations and anions according to the present invention comprises a diffusion scrubber that simultaneously collects a cation component and an anion component, and a cation anion collected by the diffusion scrubber. Two 6-way valves are provided that are switched so as to be connected in series when the component samples are supplied to the cation concentration column and the anion concentration column.

When analyzing a cation component, one of the six-way valves is switched so that the cation eluent is supplied to the cation concentration column, and the cation eluent is passed through the cation separation column and the cation suppressor. The concentration is measured by separating each cation component with an ion conductivity meter.

When continuously analyzing another system of anion components, the other 6-way valve is switched so that the anion eluent is supplied to the anion concentration column, and the anion separation column is switched. And the anion suppressor to separate the anion components by anion conductivity meter and measure the concentration.

The control unit carries out the conversion from the signals from the two 6-way valves and the electric conductivity meter to the concentration.

Therefore, the sample obtained by one collection is continuously concentrated on the cation concentration column and the anion concentration column, and the cation component and the anion component are continuously separated and analyzed, Both positive and negative ion components can be measured at the same time, and the sample amount can be reduced. Furthermore, by using an eluent, a concentration column, a separation column, a suppressor, and an electric conductivity meter dedicated to the analysis of cations and anions, highly sensitive and highly accurate measurement becomes possible.

[0017]

Embodiments of the present invention will now be described in detail with reference to the drawings.

Example 1 FIG. 1 shows an embodiment of the present invention. Air containing cation components and anion components contained in the atmosphere is introduced into the diffusion scrubber 2 through the sampling tube 1. The flow rate of the introduced air is controlled by the flow rate controller MFC4 and the air pump 5 so as to be a predetermined flow rate. Trap 3
Is a trap of water droplets that prevents minute water droplets generated in the diffusion scrubber 2 from flowing into the MFC 4. In the diffusion scrubber 2, the flow path through which the atmosphere passes and the flow path through which the pure water 6 that is the absorption liquid passes are partitioned by a semipermeable membrane, and the water-soluble ionic components in the atmosphere pass through this semipermeable membrane and pass through the semipermeable membrane. Dissolves in the ionized state. Sample pump 7 for ionized samples
By means of a 6-way valve 8 for cation concentration column 1
Introduced in 3. The cation concentration column 13 collects only cation components in the sample. The anion component in the sample passes through as it is and is sent to the 6-way valve 9. The 6-way valve 9 is used to concentrate the sample on the concentration column 2 for anions.
After controlling so as to introduce into No. 3, the anion component in the sample is concentrated and then discharged through the 6-way valve 9 as a waste liquid.

At this time, the cation eluent 11 is sent to the 6-way valve 8 by the cation eluent pump 12, but passes through the 6-way valve 8 as it is and the separation column 14
Then, the suppressor 15 and the electric conductivity meter 16 are passed through to discharge all the cation components concentrated in the previous measurement. The anion eluent 21 is continuously sent to the 6-way valve 9 by the anion eluent pump 22.
Through the separation column 24 and suppressor 25
Then, the electric conductivity meter 26 is passed through to discharge all the anion components concentrated in the previous measurement.

After the sample is introduced into the cation concentration column 13 and the anion concentration column 23 for a certain period of time, the flow paths of the 6-way valve 8 and the 6-way valve 9 are switched. The cation component concentrated in the cation concentration column 13 is passed through the eluent 11 to separate each component in the separation column 14, and the suppressor 15 reduces the background of the electrical conductivity to reduce the electrical conductivity. In step 16, it is converted into an electric signal and converted in density by the control section 600.

The anion components continuously concentrated in the concentration column 23 for anions are passed through the eluent 21 to separate each component in the separation column 24 and the suppressor 25 reduces the background of electric conductivity. Then, the electric conductivity meter 26 converts the electric signal, and the controller 600 converts the electric signal.

The configuration of the embodiment has been described in detail above.
The principles of ion chromatographic analysis are well known to those skilled in the art. Further, since it is not directly related to the present invention, its detailed description is omitted.

Next, FIG. 2 shows a time chart of the continuous cation and anion analysis method. After starting the measurement, first, sampling operation is performed. The sampling operation is an operation in which the cation component and the anion component contained in the atmosphere are collected by the diffusion scrubber 2 and the respective components are concentrated in the cation concentration column 13 and the anion concentration column 23. The eluents of the two systems during the sampling operation are directly passed through the respective separation columns to discharge all the ionic components concentrated in the previous measurement to initialize the separation columns. The sampling operation is performed for a specified time, and the ionic components are concentrated in the concentration column, and then the separation analysis operation is performed.

The separation / analysis operation is an operation in which the ion components concentrated in two concentration columns are separated for each ion component by each eluent and the concentration is measured. A constant amount of air is always introduced into the diffusion scrubber 2 from the measurement point even during the separation analysis operation. Further, a certain amount of pure water 6 is supplied to the diffusion scrubber 2 by the sample pump 7, and the water-soluble ionic components in the air are always dissolved in the pure water through the semipermeable membrane in the diffusion scrubber 2. Of the pure water (sample) in which the ionic components are dissolved, the pure water injected into the six-way valve 8 is discharged as it is. Moreover, what is introduced into the 6-way valve 9 is directly discharged as a waste liquid.

The sampling operation and the separation / analysis operation constitute one cycle of measurement, and this operation is sequentially repeated to perform continuous measurement.

Embodiment 2 As another embodiment of the present invention, the basic structure is as described above, but it is also possible to measure the concentration at multiple measurement points. The structure is shown in FIG. In this figure, FIG.
The sampling pipe 1 is provided with the multi-way switching valve 27, and the concentration at each measurement point can be measured by selecting an arbitrary measurement point.

Since the operation of each component is the same as that of the above-mentioned embodiment, detailed description will be omitted. FIG. 4 shows a time chart of the measuring method at multiple points. After the measurement is started, the measurement point 1 is selected by the multi-way switching valve 27 and the sampling operation is performed. When the separation / analysis operation of the measurement point 1 is started after the sampling for the designated time, the measurement point 2 is continuously selected by the multi-way switching valve 27, and the preliminary operation for sampling the measurement point 2 is started. The preliminary operation is an operation for adjusting the equilibrium state of the ion components moving in the semipermeable membrane of the diffusion scrubber 2 when the ion concentration at the measurement point 1 and the ion concentration at the measurement point 2 are different. When the separation and analysis operation at measurement point 1 is completed,
By switching the flow paths of the 6-way valve 8 and the 6-way valve 9, the sample at the measurement point 2 collected by the diffusion scrubber 2 is sent to the cation concentration column 13 and the anion concentration column 23 for concentration. When the separation and analysis operation of the measurement point 2 is started after the execution of the sampling for the designated time, the measurement point 3 is continuously selected by the multi-way switching valve 27, the preliminary operation for sampling the measurement point 3 is performed, and this measurement sequence is repeated. By, the cation component and the anion component at multiple points are continuously measured.

As described above, in this embodiment, the sampling tube 1 is provided with the multi-way switching valve 27, so that the cation and anion components at multiple points can be continuously measured.

Embodiment 3 As another embodiment of the present invention, the basic constitution is as described above, but as a sampling method for dissolving water-soluble ionic components in the atmosphere, in addition to the diffusion scrubber described above, impinger trapping is performed. It is also possible to use a collecting device. The measurement operation is the same as the method for continuous cation and anion analysis using a diffusion scrubber.

[0030]

As described above, the present invention has the following effects.

The first effect is to introduce a sample containing an ionic component collected by one diffusion scrubber into a cation concentration column and an anion concentration column, and use an eluent and concentration dedicated to the analysis of cations and anions. Column, separation column, suppressor,
By using the electric conductivity meter, it becomes possible to continuously measure the cation component and the anion component at the same place and at the same time with high sensitivity and high speed.

The second effect is that since the sample containing the ionic components to be introduced into the cation concentration column and the anion concentration column is collected by one diffusion scrubber, it is dedicated to the cation and the anion, respectively. Compared to the case where a diffusion scrubber is provided, the amount of exhaust air and waste liquid is reduced and the environmental load is reduced by halving the amount of air sucked from the measurement point and the consumption amount of absorbing liquid (pure water).

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a basic configuration of a cation and anion continuous analysis method of the present invention.

FIG. 2 is a time chart of the continuous analysis method shown in FIG.

FIG. 3 is a diagram showing another example of the basic configuration of the method for continuously analyzing cations and anions according to the present invention.

FIG. 4 is a time chart of the continuous analysis method shown in FIG.

FIG. 5 is a block diagram of a conventional cation and anion continuous analysis method.

[Explanation of symbols] 1 sampling tube 2 diffusion scrubber 3 traps 4 MFC (Flow control device) 5 air pump 6 pure water 7 sample pump 8 6-way valve 9 6-way valve 11 Eluent for cations 12 Eluent pump for cations 13 Concentration column for cations 14 Separation column for cations 15 Suppressors for cations 16 Electric conductivity meter for cations 21 Eluent for anion 22 Eluent pump for anion 23 Concentration column for anions 24 Separation column for anions 25 Anion suppressor 26 Electrical conductivity meter for anion 27 Multi-way switching valve 31 Mobile phase eluent 1 32 Mobile phase eluent 2 33 Eluent pump 34 Cation Guard Column 35 Exchange column for cations 36 Anion exchange column 37 Electric conductivity meter 100 sampling unit 200 Concentration unit for cations 300 Anion concentration unit 400 positive ion analyzer 500 Anion analysis unit 600 control unit

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G01N 30/08 G01N 30/08 G 30/20 30/20 A 30/46 30/46 A F term (reference) ) 2G052 AA01 AA03 AB00 AB27 AC02 AC13 AC28 AC30 AD02 AD26 AD46 BA14 CA02 CA03 CA04 CA12 CA14 CA29 CA36 CA38 EA02 ED07 ED09 FC19 FD09 FD17 GA21 GA27 HB06 HC10 HC28 HC40 JA07

Claims (10)

[Claims] 1. A sampling unit for collecting gas components in the atmosphere, a cation concentration unit having a function of concentrating cation components in the sample collected by the sampling unit, and anions in the sample. Anion concentration part having a function of concentrating components, a cation analysis part for analyzing and measuring cation components concentrated in the cation concentration part, and anions concentrated in the anion concentration part It is composed of an anion analysis part for analyzing and measuring components, and a control part for automatically and integrally controlling each part, and the cation concentration part and the anion concentration part are connected in series during sampling operation. A cation and anion continuous analysis method, which is performed by using an analyzer connected by a pipe. 2. With respect to the sample collected by the sampling unit, only the cation component is concentrated in the cation concentration unit, and the sample discharged from the cation concentration unit is introduced into the anion concentration unit. The continuous cation and anion analysis method according to claim 1, wherein only the anion component is concentrated. 3. The continuous cation and anion analysis method according to claim 1, wherein analysis is performed using an ion chromatograph in each of the cation analysis section and the anion analysis section. . 4. The continuous cation and anion analysis method according to claim 1, wherein the sampling unit is a diffusion scrubber or an impinger trapping device. 5. The continuous cation and anion analysis method according to claim 1, wherein the sampling unit includes a multi-way switching valve. 6. A sampling unit for collecting gas components in the atmosphere, a cation concentration unit having a function of concentrating cation components in the sample collected by the sampling unit, and anions in the sample. Anion concentration part having a function of concentrating components, a cation analysis part for analyzing and measuring cation components concentrated in the cation concentration part, and anions concentrated in the anion concentration part It is composed of an anion analysis part for analyzing and measuring components, and a control part for automatically and integrally controlling each part, and the cation concentration part and the anion concentration part are connected in series during sampling operation. A continuous positive and negative ion analyzer characterized by being connected by piping. 7. With respect to the sample collected by the sampling unit, only the cation component is concentrated in the cation concentration unit, and the sample discharged from the cation concentration unit is introduced into the anion concentration unit. 7. The continuous cation and anion analyzer according to claim 6, wherein only the anion component is concentrated. 8. The continuous cation and anion analyzer according to claim 6, wherein analysis is performed using an ion chromatograph in each of the cation analysis section and the anion analysis section. . 9. The continuous cation and anion analyzer according to claim 6, wherein the sampling unit comprises a diffusion scrubber or an impinger trap. 10. The continuous cation and anion analyzer according to claim 6, wherein the sampling unit includes a multi-way switching valve.