Method and apparatus for preparing a solution for quantitative analysis

Abstract

To eliminate the time and effort for measuring and managing the volume of a solution to be analyzed to be introduced to an analyzer in performing quantitative analysis of a component with an unknown concentration in a sample by using a calibration curve, thereby performing accurate analysis.SOLUTION: In performing quantitative analysis of an unknown component included in a sample by using a calibration curve, a preparation device performs, by using the same absorption tube, introducing an absorbent absorbing gas into the absorption tube and causing the absorbent to absorb sample gas generated by decomposing the sample including the unknown component by heat to prepare a solution to be analyzed for the sample, and preparing a calibration curve solution, injects a diluted solution to the solution to be analyzed in the absorption tube and the calibration curve solution in the absorption tube to obtain constant-volume solutions, and introduces the solutions to an analyzer to perform analysis.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method and apparatus for preparing an analyte solution containing a calibration curve solution to be introduced into an apparatus for detecting an unknown component (hereinafter simply referred to as "unknown component") in a sample, when quantitatively analyzing the unknown component using a calibration curve of an ion chromatograph or other analyzer. [Background technology]

[0002] In quantitative analysis of sulfur and halogens in a sample using ion chromatography (hereinafter referred to as "IC"), the sample is thermally decomposed, and the gasified components to be analyzed are collected in an absorption liquid. The absorption liquid that has absorbed the sample gas is then introduced into an IC analyzer as the solution to be analyzed.

[0003] The sample processing device recovers the components to be analyzed in the sample as a pretreatment and introduces the recovered components into the IC analyzer. The sample processing device includes a sample heating device that thermally decomposes the sample to generate sample gas; Absorbs gas A sample processing device is known that includes an absorption tube that contains an absorption liquid and is configured to allow sample gas introduced from a sample heating device to come into contact with the absorption liquid, and a diluent supply device that injects a diluent into the absorption tube (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-237316 Summary of the Invention [Problem to be solved by the invention]

[0005] When quantitative analysis of a sample is performed in an IC analyzer using the sample processing device having the above-described configuration, the analysis can be performed, for example, through the following process. First, a calibration curve solution is prepared from a calibration curve stock solution whose concentration is known in advance, and this is introduced into the IC analyzer to perform IC measurement. Next, a calibration curve solution is prepared from the same calibration curve stock solution but with a different concentration from the above, and this is introduced into an IC analyzer to perform IC measurement, and a calibration curve is created from the solution concentration and peak area. Next, an unknown sample of unknown concentration is placed into the sample processing device configured as described above, and is thermally decomposed in the sample heating device to generate sample gas. The generated sample gas is absorbed into an absorption liquid contained in an absorption tube, and a dilution liquid is injected into the absorption tube to make it a certain amount. After that, this is introduced into an IC analysis device and IC measurement is performed. Then, the peak area of ​​the unknown sample is determined by IC measurement, and the unknown sample is thermally decomposed using the calibration curve created above to determine the amount of the target component recovered in the sample gas. Quantitative analysis of the sample is then performed through a process in which the concentration in the unknown sample is determined from the amount of sample introduced and the amount of the component detected.

[0006] In the quantitative analysis of samples such as those described above, it is necessary to accurately grasp the final volume of the absorbing solution that has absorbed the sample gas and is introduced into the IC analyzer. For this purpose, it is time-consuming to precisely measure and manage the volume of the absorbing solution that has absorbed the sample gas, and the process of grasping the final volume of the absorbing solution is difficult. Furthermore, in a device that automatically introduces the calibration curve solution and the absorption solution into an IC analyzer, a mechanism is required to switch between the nozzle that serves as the introduction channel for the calibration curve solution and the nozzle that serves as the introduction channel for the absorption solution, which creates the problem that the device structure cannot be simplified.

[0007] In view of the problems associated with the prior art, the present invention aims to eliminate the need to measure and manage the volume of the solution to be analyzed introduced into an analytical device when quantitatively analyzing components contained in a sample using a calibration curve, thereby enabling highly accurate quantitative analysis to be performed automatically. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention provides a method for preparing an analyte solution to be introduced into an apparatus for detecting an unknown component in a sample using a calibration curve, the method comprising: preparing a solution to be analyzed from the sample by placing an absorbing liquid for absorbing gas in an absorption tube and allowing the sample containing the unknown component to be thermally decomposed and the generated sample gas to be absorbed into the absorbing liquid; Using the same absorption tube as above, prepare a calibration curve solution by putting a solution of known concentration into the absorption tube; A method for preparing a solution for quantitative analysis, comprising: Furthermore, the present invention is characterized in that in the above preparation method, a diluent is placed in an absorption tube to prepare the sample solution to be analyzed and the calibration curve solution. The diluent can be poured into the absorption tube up to the level detected by a liquid level sensor provided in the absorption tube, or a predetermined amount of the diluent can be poured into the absorption tube using a metering pump.

[0009] FIG. 1 shows an outline of the process for preparing a solution according to the preparation method of the present invention. The present invention uses a preparation processing system equipped with a mechanism (device) for burning and thermally decomposing a sample to generate a sample gas, and an absorption tube, to prepare a solution to be analyzed. As shown in the figure, an unknown sample with an unknown concentration is thermally decomposed to generate a sample gas, which is then absorbed in an absorption liquid placed in an absorption tube, and a dilution liquid is added to quantitatively prepare a solution for analyzing the unknown components. The calibration curve solution for preparing the calibration curve is prepared by using the same absorption tube as above, placing a solution of known concentration with known components and concentrations in it, and adding a diluent to make a quantitative amount. The solution to be analyzed prepared in the absorption tube is introduced automatically or manually from the absorption tube into an analyzer, where the components contained in the solution are analyzed. The prepared solution may be transferred from the absorption tube into a separate container, which is then transported to a storage location where the prepared solution is stored until it is analyzed by the analyzer. The injection of the absorbing solution or the solution of known concentration into the absorption tube can be performed automatically or manually using a pump that delivers the solution. The injection of the dilution solution can also be performed automatically or manually. When the dilution solution is delivered to the absorption tube using a pump, a liquid level sensor can be installed in the absorption tube to detect the total liquid volume in the tube, thereby making it possible to maintain a constant volume of the solution prepared in the absorption tube without having to check the volume of the dilution solution delivered to the absorption tube. On the other hand, when the dilution solution is delivered to the absorption tube using a metering pump, the final volume of the solution prepared in the absorption tube can be calculated from the volume of the absorbing solution placed in the absorption tube and the volume of the dilution solution delivered from the metering pump. In this way, a sample containing components with unknown concentrations is thermally decomposed, and the absorbent solution obtained by absorbing the gas generated by this process and the calibration curve solution obtained from the solution of known concentrations are prepared using the same absorption tube. This eliminates the need to burn samples of known concentrations to create a calibration curve. ,Also, If the system is equipped with a mechanism for automatically pumping the various solutions to be injected into the absorption tube, and a mechanism or device for detecting the amount of solution injected into the absorption tube, the time and effort required to adjust and check the final amounts of the absorption solution and calibration curve solution can be eliminated, and the analysis can be carried out quickly.

[0010] The present invention also provides a solution preparation device for quantitative analysis, which prepares a solution to be introduced into an apparatus for detecting an unknown component when quantitatively analyzing the unknown component contained in a sample using a calibration curve, comprising: an absorption tube in which the solution is prepared; a sample heating means for thermally decomposing the sample containing the unknown component to generate a sample gas; a diluent injection means for injecting a diluent into the absorption tube; a known concentration solution injection means for injecting a known concentration solution into the absorption tube; a function of absorbing the sample gas generated by the sample heating means into an absorption liquid placed in the absorption tube and injecting a dilution liquid into the absorption tube to prepare an analyte solution of the sample; The apparatus is characterized by having a function of injecting a solution of known concentration into the absorption tube and a dilution solution into the absorption tube to prepare a calibration curve solution. The apparatus having the above-described configuration may further be configured such that a liquid level sensor is provided in the absorption tube. Furthermore, the device for detecting unknown components can be provided with a function for automatically introducing the solution prepared in the absorption tube. In this case, an ion chromatograph analysis device, for example, can be used as the device for detecting the unknown component.

[0011] For example, the process of introducing unknown components contained in a sample into an IC analyzer using the solution preparation device of the present invention and performing quantitative analysis is carried out as follows. First, prepare a calibration curve solution by placing a known concentration solution and a dilution solution in an absorption tube, then introduce the prepared solution into the IC analyzer and perform IC measurement. Specifically, a predetermined amount (e.g., 1 mL) of a solution of known concentration (e.g., 10 ppm) is injected into the absorption tube from the known concentration solution injection means. Next, a dilution solution is injected into the absorption tube up to the liquid level sensor to make a constant volume (X mL). This is introduced into the IC analyzer as a calibration solution and IC measurement is performed. Next, the known concentration solution (10 ppm) is injected into the absorption tube from the known concentration solution injection means in a different volume (for example, 2 mL), and the diluted solution is injected up to the liquid level sensor to make a constant volume (X mL).This is introduced into the IC analyzer as the calibration curve solution and an IC measurement is performed, and a calibration curve is created from the results of the previous measurement and this measurement. A predetermined amount (e.g., 5 mL) of absorbing liquid is placed in the same absorption tube as above, and a sample of unknown composition is thermally decomposed using a sample heating means to generate sample gas, which is then absorbed into the absorbing liquid. Next, a dilution liquid is injected into the absorption tube up to the liquid level sensor to make the volume constant (X mL), and the resulting solution is introduced into an IC analyzer for IC measurement. The concentration of the unknown sample is determined from this measurement result and the calibration curve prepared earlier. [Effects of the Invention]

[0012] According to the method for preparing a solution for quantitative analysis of the present invention, the sample absorption solution obtained by absorbing the gas generated by the thermal decomposition of a sample containing an unknown component and the calibration curve solution obtained from a solution of known concentration are prepared using the same absorption tube, thereby eliminating the need to burn a sample of known concentration to prepare an absorption solution of known concentration in order to create a calibration curve. This also eliminates the need to adjust and check the final volume of the absorption solution, allowing for faster analysis. Furthermore, according to the solution treatment device of the present invention, in measurements using this device, it is possible to calculate the concentration and amount of a target component in an unknown sample even if the liquid volume up to the liquid level sensor installed in the absorption tube is unknown. It takes time and effort The cumbersome process of measuring and managing the volume of liquid to obtain a quantitative amount of the solution to be analyzed is no longer necessary, and highly accurate quantitative analysis can be performed automatically regardless of whether the unknown sample is liquid or solid. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a diagram showing an outline of a process for preparing a solution according to a solution preparation method of the present invention. [Figure 2] 1 is a diagram showing a schematic configuration of an embodiment of a solution preparation device of the present invention. [Figure 3] FIG. 3 is a diagram showing a schematic configuration of the absorption tube of FIG. 2. DETAILED DESCRIPTION OF THE INVENTION

[0014] A preferred embodiment of the solution preparation device of the present invention will now be described with reference to the drawings. Figure 2 is The figure shows the schematic configuration of an apparatus for quantitatively analyzing unknown components contained in a sample using an IC analyzer, in which reference numeral 1 denotes the IC analyzer and reference numeral 2 denotes a solution preparation apparatus of the present invention that prepares an analyte solution including a calibration curve solution to be introduced into the IC analyzer.

[0015] The IC analyzer 1 is a well-known device that separates ions and polar molecules in a solution to be analyzed using ion exchange resin and analyzes anions and cations by detecting the electrical conductivity or absorbance of the solution. The IC analyzer 1 comprises a pump, a separation column (measuring tube) in a thermostatic bath, a detector, and a Consists of Alternatively, a suppressor for reducing background may be further provided between the separation column and the detector. A sample introduction valve 11 is arranged in a solution extraction pipe 71 extending from a solution containing pipe (to be described later) to the IC analyzer 1 .

[0016] The solution preparation device 2 is configured to include an absorption tube 3 in which the solution to be analyzed is stored and which delivers the solution to be analyzed to the IC analysis device 1, a sample heating means 4 which thermally decomposes the sample to generate sample gas, a dilution liquid injection means 5 which injects a dilution liquid into the absorption tube 3, and a known concentration solution injection means 6 which injects a solution of known components and concentrations into the absorption tube 3.

[0017] The absorption tube 3 is made of a light-transmitting material such as glass and has an internal volume of 10 to 100 cm 3 The absorption tube 3 is a cylindrical container of approximately 1000 psi. As will be described later, in the process of heating a sample with a sample heating means 4 and recovering the sample gas, an absorbing liquid that absorbs the sample gas is contained in the absorption tube 3. The absorbing liquid may be, for example, a hydrogen peroxide solution with a concentration of 0.001 to 1%, a dilute alkaline solution, or water. The absorbing liquid is injected into the absorption tube by a solution delivery pump (not shown). The absorbing liquid may also be injected manually.

[0018] The upper end of the absorption tube 3 is sealed with a lid to prevent the solution to be analyzed from scattering, and the solution extraction tube 71 and a known concentration solution injection tube 79 connected to the known concentration solution injection means 6 are inserted into this lid. A gas inlet pipe 75 is connected to the outer periphery of the absorption tube 3, and the sample gas generated by the sample heating means 4, which will be described later, is introduced into the tube through the gas inlet pipe 75 and is absorbed by the absorbing liquid contained in the absorption tube 3. The diluent delivered from the diluent injection means 5 is also injected into the absorption tube 3 through the gas inlet pipe 75. The used absorbing liquid and washing water in the absorption tube 3 are discharged to the outside of the tube through a drain pipe 77.

[0019] The sample heating means 4 is configured to be able to supply oxygen and Heating means 42 The sample heating means 4 comprises an outer tube 41 that can be heated from the outer periphery by a heater, an inner tube 43 that can supply a carrier gas and is inserted into the outer tube 41 from its base end, and a boat 44 for supplying a sample that is inserted into the inner tube 43 from its base end. In the sample heating means 4, the outer tube 41 and the inner tube 43 form a reaction tube. Usually, the outer tube 41, the inner tube 43, and the boat 44 are made of quartz.

[0020] A cylindrical electric furnace of approximately 0.7 to 1.5 kW is typically used as the heating means 42 for heating the outer tube 41 and inner tube 43, which are reaction tubes. In other words, the outer tube 41 is inserted into the cylindrical interior of the electric furnace. An oxygen inlet pipe 72 for supplying oxygen to the outer tube 41 is connected to the base end of the outer tube 41. Although not shown, the oxygen inlet pipe 72 extends from an oxygen container and is equipped with a flow controller midway. Furthermore, a sample gas outlet pipe 74 for extracting the sample gas obtained by thermal decomposition is provided at the tip of the outer tube 41, and this sample gas outlet pipe 74 is connected to the gas inlet pipe 75. The tip of the inner interior of the outer tube 41 is typically filled with quartz wool (not shown) to stabilize combustion.

[0021] The inner tube 43 is a conduit for guiding the sample gas generated by the thermal decomposition of the sample to the outer tube 41. Its tip opening (the end on the left in FIG. 2 ) is inserted into the outer tube 41 at a position corresponding to approximately the center of its length to promote combustion of the generated gas. The base end of the inner tube 43, i.e., the portion not inserted into the outer tube 41 (approximately half the length on the right in FIG. 2 ), is exposed to the outside from the base end of the outer tube 41. A carrier gas inlet 73 for supplying a carrier gas such as argon is connected to the base end of the inner tube 43. Although not shown, the carrier gas inlet 73 extends from a carrier gas container and is equipped with a flow controller midway. A sample introduction port 45 is attached to the portion of the inner tube 43 exposed from the outer tube 41. The sample introduction port 45 has a structure in which the outer periphery of an opening provided in the inner tube 43 is covered with a lidded casing.

[0022] The sample supply boat 44 is a small dish that carries a sample and moves back and forth between the sample inlet 45 and the vicinity of the tip of the inner tube 43 inside the inner tube 43. It is shaped, for example, like a shallow, flat, elongated box. The boat 44 is attached to the tip of an operating rod that moves back and forth by a boat controller 46. Specifically, a short-axis cylindrical metal piece that fits loosely inside the inner tube 43 is attached to the base end of the operating rod, and a ring-shaped magnet or electromagnet that fits loosely inside the inner tube 43 is attached to the outer periphery of the inner tube 43 and moves linearly by a drive mechanism (e.g., a drive mechanism composed of a servo motor and a rack mechanism) of the boat controller 46. The operating rod moves inside the inner tube 43 following the movement of the rod.

[0023] Furthermore, in order to supply sufficient water vapor to the inner tube 43, the sample heating means 4 is provided with a water supply pipe 76 connected to a water supply means connected to the outer periphery of the inner tube 43 at a position corresponding to the base end of the outer tube 41, so that water can be supplied from outside, and with a water vapor generating section having a jacket structure that generates water vapor using residual heat from the heating means 42. A water vapor introduction hole (not shown) is provided in the wall surface corresponding to the upper surface side of the horizontally disposed inner tube 43, and the water vapor generated in the water vapor generating section is introduced through this hole into the reaction region of the inner tube 43.

[0024] The diluent injection means 5 is a means for injecting water, which is a diluent, into the solution containing tube 3, and the diluent delivered from the diluent injection means 5 is injected into the absorption tube 3 through the diluent delivery tube 78 and the gas blowing tube 75. A pump for delivering the diluent can be used as the diluent injection means 5. For example, the diluent may be delivered to the absorption tube 3 using a metering pump such as a syringe pump.

[0025] The known concentration solution injection means 6 is a means for injecting a known sample solution with known components and concentrations into the absorption tube 3, and the known concentration solution is injected into the solution containing tube 3 through a known concentration solution injection tube 79. As the known concentration solution injection means 6, a syringe pump or the like can be used, which is capable of injecting any amount into the absorption tube 3. The known concentration solution is a solution in which a known amount of the component to be measured is dissolved, and commercially available standard solutions, certified substances, or solutions prepared by appropriately mixing substances and solutions can be used.

[0026] As shown in FIG. 3, the liquid level sensors 8, 8 provided in the absorption tube 3 can be configured by, for example, a light source such as a light-emitting diode or a semiconductor laser, and a photosensor including a light-receiving element such as a photodiode or an optical array that detects the intensity of light from the light source that has passed through the solution containing tube 3. Although not shown, an amplifier for amplifying the output signal of the liquid level sensor 8, 8, a signal converter for digitizing the output signal, and a calculation processing means for calculating the obtained digital signal are used. Absorber tube 3The liquid level detecting means is provided in a control device (not shown) which will be described later.

[0027] In the solution preparation device 2 of this embodiment, the dilution liquid injection means 5 and the known concentration solution injection means 6 are configured by water pumps, and the dilution liquid and the known concentration solution are automatically injected into the absorption tube 3. The absorption liquid is also automatically injected from the suction liquid reservoir by a water pump (not shown) into the absorption tube 3. In addition, the solution to be analyzed prepared in the absorption tube 3 is also automatically introduced into the IC device 1 by a water pump (not shown).

[0028] The operation of each of the components that make up the solution preparation apparatus 2, including the sample heating means 4, dilution liquid injection means 5, known concentration solution injection means 6, valves such as the gate valve, and liquid level sensors 8, 8, is controlled by a control device consisting of a computer loaded with a predetermined program, and is configured to perform functions of preparing solutions for quantitative analysis, such as absorbing the sample gas generated by the sample heating means 2 into the absorption liquid placed in the absorption tube 3 and injecting a dilution liquid into the absorption tube 3 to prepare an analyte solution of the sample, and injecting a known concentration solution and a dilution liquid into the absorption tube 3 to prepare a calibration curve solution. That is, in the process of preparing a solution to be analyzed by thermally decomposing a sample of unknown components, the injection of absorbing liquid into the absorption tube and the thermal decomposition of the sample are carried out automatically under the control of the control device, and the sample gas produced by the thermal decomposition is absorbed by the absorbing liquid. Next, diluent is injected into the absorption tube 3 from the diluent injection means 5, and when the solution in the absorption tube 3 reaches the liquid level sensors 8,8, the control device stops the operation of the diluent injection means 5 based on the signal from the liquid level sensors 8,8, and the volume of the solution to be analyzed prepared in the absorption tube 3 is kept constant. In the process of preparing a calibration curve solution from a solution of known concentration, the known concentration solution is injected into the absorption tube 3 from the known concentration solution injection means 6 under the control of the control device, and when the injection amount reaches a predetermined amount, the control device stops the solution injection operation of the known concentration solution injection means 6. Next, the control device operates the diluent injection means 5 to inject the diluent into the absorption tube 3, and when the solution in the absorption tube 3 reaches the liquid level sensors 8, 8, the control device stops the operation of the diluent injection means 5 based on the signal from the liquid level sensors 8, 8, and the calibration curve solution prepared to a predetermined concentration in the absorption tube 3 is kept at a constant volume. The solution to be analyzed and the calibration curve solution, which have been adjusted to a fixed volume in the absorption tube 3, are introduced into the IC analyzer 1 by operating a water pump (not shown) using a control device, and IC measurement is carried out.

[0029] The process of quantitatively analyzing a sample containing an unknown component using the solution preparation apparatus 2 of this embodiment configured as described above is carried out, for example, as follows. First, a solution of known concentration is placed in the absorption tube 3 to prepare a calibration curve solution, and the prepared solution is introduced into the IC analyzer 1 to perform IC measurement. Specifically, a predetermined amount of a solution of known concentration is injected into the absorption tube 3 from the known concentration solution injection means 6. Next, the dilution solution is injected into the absorption tube 3 from the dilution solution injection means 5 to the liquid level sensors 8, 8 to make a constant volume, and this is introduced into the IC analyzer 1 as a calibration curve solution for IC measurement. Although not shown, the absorption tube 3 is provided with oxygen gas and argon gas supplied, and the injection of the solution of known concentration is performed with the supply of both gases temporarily stopped. After the dilution solution has been injected, both gases are supplied into the absorption tube 3, so that the solution of known concentration and the dilution solution are mixed within the absorption tube 3. Next, a solution of known concentration is injected into the absorption tube 3 from the known concentration solution injection means 6 using a different liquid volume from the previous one, and the diluted solution is injected from the diluted solution injection means 5 up to the liquid level sensors 8, 8 to make a constant volume, and this is introduced into the IC analyzer 1 as a calibration curve solution to perform IC measurement, and a calibration curve is created from the results of the previous measurement and this measurement. A predetermined amount of absorbing liquid is placed in the absorption tube 3, and a sample of unknown concentration is thermally decomposed by the sample heating means 4 to generate sample gas. The generated sample gas is absorbed into the absorption liquid. Next, with the supply of the oxygen gas and argon gas stopped, diluent is injected into the absorption tube 3 from the diluent injection means 5 up to the liquid level sensors 8, 8 to make the volume constant. After that, the two gases are supplied into the absorption tube 3 to mix the solutions, and the solution is introduced into the IC analyzer 1 for IC measurement. The concentration of the unknown sample is determined from this measurement result and the calibration curve prepared earlier.

[0030] With the solution preparation apparatus configured in this manner, it is possible to calculate the concentration and amount of the target component in the unknown sample even if the amount of liquid up to the liquid level sensor provided in the absorption tube is unknown. This eliminates the need for the time-consuming and tedious measurement and management of the liquid volume required to obtain a quantitative amount of the solution to be analyzed, and makes it possible to automatically perform highly accurate quantitative analysis regardless of whether the unknown sample is liquid or solid. Furthermore, the following specific practical effects can be obtained. That is, since the system has a function for automatically diluting a solution of known concentration, which is the original calibration curve solution, there is no need to prepare a prepared calibration curve solution in advance. Dilution liquid is added to the calibration curve solution and the absorption liquid that has absorbed the sample gas of the sample containing the unknown component, and the volume is made constant using a liquid level sensor installed in the same absorption tube, so there is no need to determine the liquid volume up to the liquid level sensor. In addition, the function of injecting the absorbing liquid into the absorption tube can also be used to prepare the calibration curve solution, so that the calibration curve solution can be prepared by adding the absorbing liquid that has absorbed the sample gas of the unknown sample to the calibration curve solution. The unknown sample solution to be analyzed and the calibration curve solution can be made to have the same composition and introduced into the IC analyzer for measurement. When creating a calibration curve, changing the amount of calibration solution introduced into an IC analyzer can cause a problem of baseline shift. With the solution preparation device configured as described above, the amount of solution introduced into the IC analyzer remains constant, and only the concentration of the calibration solution is changed, so the baseline does not fluctuate and there is no risk of a decrease in analytical accuracy. Furthermore, compared to creating a calibration curve by changing the amount of solution introduced into the IC analyzer, the dilution rate of the known concentration solution can be increased, making it possible to create a calibration curve over a wide concentration range. Furthermore, when the method of preparing a test line solution in advance and then performing IC measurement on the absorbed solution obtained by burning and absorbing an unknown sample is performed using an apparatus equipped with a mechanism for automatically introducing the solution into the IC measurement device, a valve is required to switch between the nozzle that draws in the calibration line solution and the nozzle that draws in the analyte solution prepared by similarly drawing in the sample gas. However, with the solution preparation device configured as shown in the figure, the calibration line solution and the analyte solution of the unknown sample are contained in the same absorption tube and can be introduced into the IC analysis device separately, eliminating the need for a switching valve. [Example]

[0031] The effectiveness of the method for preparing a solution for quantitative analysis of the present invention was confirmed by quantitatively analyzing a sample. An ethanol solution of (4-chloro-3-trifluoromethyl)phenylthiourea (F: 179.8 μg / mL, Cl: 111.8 μg / mL, S: 101.1 μg / mL) was used as a sample, and the contents of fluorine, chlorine, and sulfur in the sample were analyzed by combustion ion chromatography. We performed IC analysis using a calibration curve solution prepared in the absorption tube of the solution preparation device described above, and a conventional IC analysis method using calibration curve solutions prepared individually and manually in volumetric flasks, to confirm the differences in analytical results between these two analytical methods. Three solutions (samples) were prepared using each method and subjected to IC analysis. The results are shown in Table 1. As shown in Table 1, even when the analytical method of the present invention was used, analytical results equivalent to those of the conventional analytical method were obtained, and it was confirmed that the present invention can also perform analysis with the same level of accuracy as the conventional method.

[0032] [Table 1]

[0033] The configurations and component shapes of the solution preparation device described and illustrated above are merely examples, and the present invention is not limited to the configurations and shapes described and illustrated, but may have other appropriate configurations and shapes. The present invention can be applied as a method and apparatus for preparing a solution for various analytical devices, including an ion chromatograph, that quantitatively analyze unknown components contained in a sample using a calibration curve. [Explanation of symbols]

[0034] 1 IC analyzer, 2 solution preparation device, 3 absorption tube, 4 sample heating means, 5 dilution solution injection means, 6 known concentration solution injection means, 8 liquid level sensor

Claims

1. 1. A method for preparing an analyte solution to be introduced into an apparatus for detecting an unknown component in a sample using a calibration curve, the method comprising: preparing a solution to be analyzed from the sample by placing an absorbing liquid for absorbing gas in an absorption tube and allowing the sample containing the unknown component to be thermally decomposed and the generated sample gas to be absorbed into the absorbing liquid; Using the same absorption tube as above, prepare a calibration curve solution by putting a solution of known concentration into the absorption tube; A method for preparing a solution for quantitative analysis, comprising:

2. 2. The method for preparing a solution for quantitative analysis according to claim 1, wherein the preparation of the sample solution to be analyzed and the preparation of the calibration curve solution are carried out by adding a diluting solution to an absorption tube.

3. 3. The method for preparing a solution for quantitative analysis according to claim 2, wherein the diluent is added to the absorption tube up to a level that can be detected by a liquid level sensor provided in the absorption tube.

4. 3. The method for preparing a solution for quantitative analysis according to claim 2, wherein a fixed amount of the diluent is fed into the absorption tube by a metering pump.

5. 1. A solution preparation device for preparing an analyte solution to be introduced into an apparatus for detecting an unknown component in a sample using a calibration curve, the apparatus comprising: an absorption tube in which the solution is prepared; a sample heating means for thermally decomposing the sample containing the unknown component to generate a sample gas; a diluent injection means for injecting a diluent into the absorption tube; a known concentration solution injection means for injecting a known concentration solution into the absorption tube; a function of absorbing the sample gas generated by the sample heating means into an absorption liquid placed in the absorption tube and injecting a dilution liquid into the absorption tube to prepare an analyte solution of the sample; a function of injecting a solution of known concentration into the absorption tube and a dilution solution to prepare a calibration curve solution; A solution preparation device for quantitative analysis comprising:

6. 6. The apparatus for preparing a solution for quantitative analysis according to claim 5, wherein the absorption tube is provided with a liquid level sensor.

7. 7. The device for preparing a solution for quantitative analysis according to claim 5, further comprising a function for automatically introducing the solution prepared in the absorption tube into the device for detecting an unknown component.

8. 8. The apparatus for preparing a solution for quantitative analysis according to claim 7, wherein the apparatus for detecting the unknown component is an ion chromatograph.

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