JPH10274657A - Device for generating and analyzing hydride - Google Patents

Abstract

PROBLEM TO BE SOLVED: To select the concentration of an acid and that of a reducing agent corresponding to a sample and to perform a highly-sensitive automatic measurement with a small amount of sample liquid by introducing the sample liquid to a reaction part and by generating and analyzing the hydride gas of an element to be analyzed in the sample by the acid and the reducing agent. SOLUTION: A sample liquid in a sample introduction part 11 is introduced to a reaction part 13 by a carrier flowing in a pipeline 17. Then, when an element to be measured is inputted to the computer of a control part 20, an acid and a reducing agent with selected kind and concentration are introduced from an acid-supplying part 14a and a reducing agent supplying part 14b of a sample introduction part 14 to the reaction part 13 and reacts with a target constituent such as a semi-metal element in the sample liquid, thus generating a hydride gas. The sample liquid containing the hydride gas is introduced to a gas/liquid separation part 15 and is separated into a gas and a liquid by an inert gas. Then, the hydride gas being separated into the gas and the liquid is introduced to a detection part 16 and the target element is analyzed and measured by, for example, an atomic absorption spectrometer and an ICP emission spectrometer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydride generation analyzer for generating and analyzing a hydride of a target component of a sample.

[0002]

2. Description of the Related Art In the analysis of metalloid elements, if atomic absorption analysis or ICP analysis is performed, the detection sensitivity is low and the measurement error may be large. In this case, there is an advantage that the efficiency of introduction of the analysis target component into the atomized portion is improved, and almost all of the introduced hydride is atomized, so that the detection sensitivity is high and the measurement accuracy is improved.

Usually, in order to generate hydride, a reducing agent is added to a sample together with an acid. However, it is necessary to prepare hydride generation conditions according to the sample. Liquidity is adjusted manually. Therefore, each time the element to be measured is different, human labor is required, and rapid measurement cannot be performed. Further, in this type of conventional analyzer, it is necessary to manually adjust the dilution ratio and the sample introduction amount for the concentration outside the measurement range of the device, and there is a problem that the adjustment of the sample solution is troublesome. Further, the conventional apparatus mainly employs a continuous suction method, a batch addition method, and an FIA method (loop injection method) as a sample introduction method. However, in the continuous suction method, a large amount of the sample solution (at least about 20 ml) is used. Therefore, there is a limit in performing a trace amount analysis because the concentration ratio is limited. In the batch addition method, since the air segment method is used, the sample liquid remains in the pipeline to leave a memory, and it is necessary to clean the pipeline each time measurement is performed.

[0004]

SUMMARY OF THE INVENTION The present invention has solved the above-mentioned problems in the conventional hydride generation analyzer, and can measure even a small amount of sample liquid, has a small residual memory of the measurement system, and has a more preferable embodiment. Allows the pre-reduction to be performed together with the selection of the acid concentration and the reducing agent concentration according to the sample, and since a series of operations from the introduction of the sample solution to the analysis can be automatically performed, the change of the element to be measured can be performed. It is an object of the present invention to provide a hydride generation analyzer capable of sequentially analyzing multiple elements including the hydride.

[0005]

The analyzer according to the present invention reduces the residual memory in the pipeline by feeding a carrier and introducing a sample into a measurement system instead of the air segment system, and also allows the sample injection. The amount was sufficient to be as small as the batch addition method (1 ml or less) so that the concentration ratio of the sample solution was increased to enable measurement. More preferably, a means capable of adjusting the acid concentration and the reducing agent concentration is provided in the acid supply section and the reducing agent supply section forming the reagent introduction section, so that these concentrations can be selected according to the sample, and A control circuit for integrally controlling is provided so that a series of operations from introduction of a sample solution to analysis can be automatically performed.

That is, according to the present invention, there is provided (1) a flow analyzer in which a sample introduction section, a reagent introduction section, a reaction section, a gas-liquid separation section, and a detection section are sequentially and integrally connected by a pipe. The sample introduction section is provided with a loop for holding a sample solution, the sample solution in the loop is introduced into the reaction section through a conduit by a carrier, and a reagent introduction section is connected to the reaction section, The reagent introduction section is provided with an acid supply section and a reducing agent supply section, respectively, and the hydride gas of the element to be analyzed in the sample is generated by the acid and the reducing agent supplied to the reaction section. Introducing hydrogen into the gas-liquid separation section from the reaction section to the gas-liquid separation section, and introducing the hydride gas separated by gas and liquid by the inert gas introduced into the gas-liquid separation section to the detection section for analysis. A compound generation analyzer is provided.

In the analyzer of the present invention, (2) a pre-reducing agent supply unit is provided in the reagent introducing unit together with the acid supply unit and the reducing agent supply unit, and the pre-reducing agent is supplied to the sample liquid in the reaction unit. Includes an analyzer to which the acid and reducing agent are later supplied.

Further, the analyzer of the present invention preferably has means for selecting the concentrations of the acid and the reducing agent. That is, in the above analyzer, (3) an analyzer in which an acid having a different concentration is held in an acid supply section and an acid concentration is selected according to a sample liquid; and (4) a reducing agent having a different concentration in a reducing agent supply section. An analyzer in which an agent is held and the concentration of the reducing agent is selected in accordance with the sample liquid. An analyzer in which the acid is diluted and supplied to the reaction section. (6) The reducing agent supply section is provided with a supply means for the reducing agent and the dilution water, respectively. Including the analyzer supplied to the unit.

Further, the analyzer according to the present invention comprises: (7) an analyzer in which a plurality of pre-reducing agents are held in a pre-reducing agent supply unit, wherein these are selected according to a sample solution; A control circuit that integrally controls the operations of the introduction unit, the reaction unit, the gas-liquid separation unit, and the detection unit is provided, and includes an analyzer that automatically performs a series of operations from introduction of a sample solution to analysis.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on an embodiment shown in the drawings. FIG. 1 is a conceptual diagram showing a measurement system according to the analyzer of the present invention, and FIGS. 2 to 4 are conceptual diagrams showing a configuration example of a reagent introduction unit. As shown in the drawing, the analyzer of the present invention has a continuous configuration in which a sample introduction unit 11, a reaction unit 13, a reagent introduction unit 14, a gas-liquid separation unit 15, and a detection unit 16 are connected sequentially and integrally by a pipe line 17. A flow analyzer, in which a reagent is added while a sample solution flows through a pipe line, guided to a reaction unit, reacts in a state suitable for analysis, and subsequently guided to a detection unit for analysis by flow injection (FI).
It is a device based on.

The sample introducing section 11 has an opening / closing valve interposed in a pipe 17 of a measuring system, and the opening / closing valve is provided with a loop for holding a sample liquid. A six-way valve or the like may be used as the opening / closing valve, and a valve having the above-mentioned loop attached to a switching portion of the pipeline may be used. Preferably, an autosampler 12 is connected to the loop so that a fixed amount of sample solution is automatically introduced into the loop. When the open / close valve is opened with respect to the pipeline of the measurement system, the sample liquid in the loop is introduced into the pipeline by the carrier flowing through the pipeline, and is introduced into the reaction unit through the pipeline.

The reaction section 13 is, for example, a section in which the pipe 17 is formed in a coil shape so as to secure a reaction time. A reagent introduction section 14 is connected to the reaction section 13, and the reaction with the reagent supplied to the reaction section 13 proceeds while the sample liquid flows through the reaction section 13.

The reagent introduction section 14 is provided with an acid supply section 14a and a reducing agent supply section 14b, and the acid supply section 14a is connected to a measurement system pipe 17 through a pipe 14d and a liquid feed pump 14e. The reducing agent supply unit 14b communicates with the reaction unit 13 through a conduit 14d and a liquid feed pump 14e. An acid and a reducing agent are each introduced into the reaction section through these pipes 14d, and react with target components such as metalloid elements in the sample solution to generate hydrides. The acid is mixed with the sample solution to make the sample zone a reducing atmosphere,
Maintain the acidity to generate hydrogen. Further, the reducing agent reacts with the sample liquid in this state to combine the liberated hydrogen with the analysis component element to generate a hydride. The type of acid and reducing agent is appropriately used depending on the type of the element to be analyzed and the properties of the sample solution, but hydrochloric acid is generally used as the acid for the analysis of metalloid elements and the like, and hydrogenating is used as the reducing agent. Sodium boron (NaBH ₄ ) or the like is used.

The reagent introduction section 14 is preferably provided with an acid supply section 14a and a reducing agent supply section 1 as shown in FIG.
A preliminary reducing agent supply section 14c is provided along with 4b, and a preliminary reaction section 13a is provided in the reaction section 13 corresponding to this.
The pre-reaction section 13a includes a pipe 14 and a liquid feed pump 1
4e and the acid supply unit 1
4a, and supplies a pre-reducing agent and an acid to the sample liquid in the pre-reaction section 13a. The pre-reducing agent reacts with the sample solution to convert arsenic (As) from pentavalent to trivalent, for example, selenium (Se).
Is reduced from hexavalent to tetravalent to have a valence that facilitates generation of hydride. The sample liquid in this state is introduced into the reaction section 13 and a reducing agent is added to generate a hydride. In the analysis of a metalloid element or the like, potassium iodide or the like is used as a preliminary reducing agent, for example, for arsenic (As).

Preferably, the acid supply section 14a and the reducing agent supply section 14b are provided with means for appropriately selecting their concentrations, and the preliminary reducing agent supply section 14c is provided with means for selecting a plurality of preliminary reducing agents. Is provided. Specifically, as shown in FIG. 3, a plurality of containers 14j and 14k holding different concentrations of acids or reducing agents are provided in the acid supply unit 14a and the reducing agent supply unit 14b, respectively, so that they can be appropriately selected. good. In the example shown, 1M, 2M, 4M,
6M hydrochloric acid at four concentrations, 0.5%, 1.0%, 2.0%
% And 5.0% sodium borohydride are provided, and these concentrations are selected according to the state of the sample solution. It is sent to the reaction section 13a.

As another means for adjusting the concentration, as shown in FIG. 4, an acid supply unit 1 is supplied by a liquid supply pump 14f for supplying a high-concentration acid and a liquid supply pump 14g for supplying dilution water.
4a, a reducing agent supply section 14b is formed by a liquid sending pump 14h for supplying a high-concentration reducing agent and a liquid sending pump 14i for supplying dilution water, and the amount of the diluting water with respect to the acid and the reducing agent is adjusted. Alternatively, the acid and the reducing agent may be adjusted to target concentrations and supplied to the reaction section 13 through the pipe 14d.

A plurality of containers 14m each holding various reducing agents are provided in the preliminary reducing agent supply section 14c, and these reducing agents are appropriately selected according to the sample liquid. For example, each container holds a hydrogen peroxide solution, potassium iodide, water, or the like as a preliminary reducing agent, and is appropriately selected.

The gas-liquid separation unit 15 is a closed container to which an inert gas is supplied together with a sample liquid containing hydride, and discharges an inert gas supply line 15a and waste liquid to the outside together with a measurement system line 17. The pipe 15b is connected. The pipe 17 of the measurement system communicates with the detection unit 16, and the hydride gas separated by the inert gas from the gas-liquid separation is introduced into the detection unit 16 through the pipe 17.

The detection unit 16 is provided with an atomic absorption analyzer, an ICP emission spectrometer, or the like, and analyzes a target element introduced as a hydride.

The analyzer preferably comprises a sample introduction section 11, a reagent introduction section 14 (acid supply section, reducing agent supply section and preliminary reducing agent supply section), a reaction section 13, a gas-liquid separation section 15, and a detection section 16. Are connected by a control circuit 21. The operations of these parts are automatically controlled by a computer provided in the control unit 20, and a series of operations from introduction of a sample solution to analysis are automatically performed. . Further, in the case where a means for selecting an acid concentration, a reducing agent concentration, and a pre-reducing agent is provided, an acid having a desired concentration can be obtained automatically or by inputting a selection command according to the type of the element to be analyzed and the state of the sample solution. And a reducing agent and further a pre-reducing agent are selected,
It is supplied to the reaction section or the preliminary reaction section. Alternatively, an acid and a reducing agent having a desired concentration are formed by adjusting a mixing ratio of a reagent and water by adjusting a dilution water amount with respect to an acid and a reducing agent, and supplied to a reaction section or a preliminary reaction section.

[0021]

[Measurement Example] A measurement example using the apparatus of the present invention is shown below. In this example, an example of measuring arsenic using an atomic absorption photometer as a detector will be described. In the following description, the flow rate, the type of the reagent, and the like are merely examples, and the use of the device of the present invention is not limited to these.

Measurement Example 1 The apparatus having the measurement system shown in FIG. 3 is started according to the following procedure. (B) Activate the measurement system, use water as a carrier, send a constant flow of water to the pipe 17 to clean the inside of the pipe, and initialize the autosampler 12 and attached valves, The flow rate of the argon gas introduced into the gas-liquid separation unit 15 is set. (B) Activate the detection unit 16 to perform calibration of the atomic absorption spectrometer, etc., residual heat of the hollow cathode lamp inside the spectrometer, and heating of the tubular furnace. (C) Input the measurement conditions from the control computer, and the position of the standard solution on the autosampler and its concentration, the number of sample solutions,
Set the number of repeated measurements for each solution. In addition, reagents (NaB
H _4, HCl) type, type of pre-reduction agent, flow rate of each of these reagents, optimal reagent concentration, carrier flow rate, the argon gas flow rate, reactor temperature, the temperature of the hydride generating tube furnace, to no lower limit of quantitation concentration Change the settings such as absorbance, upper limit of quantitation or absorbance as necessary.

(D) Input the element to be measured into the control computer. When measuring a plurality of elements, all the elements are specified and input. Hereinafter, an example of arsenic measurement will be described. (E) In the measurement of arsenic, as a standard condition, 3M hydrochloric acid as an acid and 1% as a reducing agent automatically from a computer as a standard condition.
NaBH ₄ , 40% KI solution as pre-reducing agent. According to this designation, the above reagent is selected in the acid supply section, the reducing agent supply section and the preliminary reducing agent supply section, and is automatically supplied to the preliminary reaction section and the reaction section at a rate of 2 ml / min each. (F) This state is maintained for a designated time (for example, 3 minutes) to stabilize the measurement system. On the other hand, in the detector, the hollow cathode lamp of the measuring means is set at the optimum position on the measuring optical path, and the measuring wavelength is automatically set to the resonance line wavelength (1) at which the highest sensitivity of arsenic is obtained.
93.7 nm).

(G) After the measurement system is stabilized, the measurement of the standard solution and the sample solution is sequentially performed. In the sample solution, the amount of 500 μl of carrier (water, etc.) under standard conditions is
Is introduced into the sequential measurement system. After measuring each sample solution,
The absorbance is calculated (peak height or peak area), and the concentration of the measurement element (such as a metalloid element) in the sample solution is calculated based on the measured absorbance. The result is displayed on a display device connected to the control unit and recorded in the control unit.

(H) The necessity of re-measurement is determined as necessary, and re-measurement is performed. As an example requiring re-measurement, a re-measurement is performed as follows for a sample having a high concentration exceeding the range of the calibration curve. (1) First, the sample injection amount is measured as 1/2 (250 μl) of the first measurement. (2) When the measured concentration exceeds the range of the calibration curve even after the above adjustment, the sample solution is measured with the sample injection amount being １ of the injection amount. (3) If the measured concentration still exceeds the range of the calibration curve by the above adjustment, repeat this operation to control the sample injection amount so as to fall within the range of the calibration curve.

(4) Further, if the measured concentration still exceeds the range of the calibration curve by such adjustment of the injection amount,
The injection amount of the sample is held at the amount immediately before the measurement (the last amount repeatedly adjusted in the above (3)), and the sample having a lower hydrochloric acid concentration is sequentially selected and measured. If this measured concentration is within the range of the calibration curve,
The highest concentration standard solution was measured again under these conditions, and the desensitization rate (D)
Is multiplied by the concentration of the element to be analyzed in the sample, which is calculated by the calculation, and quantification is performed. (5) If the measured concentration exceeds the range of the calibration curve even after the above adjustment of the acid concentration, adjust the sample injection amount and hydrochloric acid concentration immediately before the measurement or the concentration (the last amount, concentration after repeated adjustment in (4) above). ) And successively select a reducing agent having a lower concentration of NaBH ₄ for measurement. If this is within the range of the calibration curve, the standard solution with the highest concentration is measured again under these conditions, and the concentration of the element to be analyzed in the sample calculated by obtaining the desensitization rate (D) is multiplied by this to determine the quantification. Do. (6) If it does not fall within the range of the calibration curve, add the data indicating that it is more than the upper limit of quantification and perform the next measurement.

(D) Among the samples requiring re-measurement, the samples whose measurement results are considered to be displayed at a low concentration below the lower limit of quantification or at a concentration lower than the lower limit of quantification due to interference with coexisting substances or the like are as follows. Repeat the measurement. (1) Double the sample injection volume (1000 μl) and measure the corresponding sample solution. (2) If the above adjustment does not result in a lower limit of quantification, measure the amount by injecting the sample twice as much as in (1) above. If the measured concentration is still below the lower limit of quantification, this operation is repeated to adjust the concentration to fall within the quantification range. (3) Even after the adjustment in (2) above, if the amount is still below the lower limit of quantification, the sample injection volume is maintained at the volume immediately before measurement (the last volume repeatedly adjusted in (2) above), High concentration NaBH ₄ is selected and measured. This is repeated within a settable density range. (4) If the adjustment in (3) above is still below the lower limit of quantification, maintain the sample injection volume at the volume immediately before measurement (the last volume repeatedly adjusted in (3) above), The concentration and the reducing agent concentration are selected and measured, and this is repeated within the settable concentration range. (5) Finally, for the sample below the lower limit of quantification, add the data indicating that it is lower than the lower limit of quantification to the next measurement.

When a plurality of elements to be measured are to be analyzed, measurement conditions are prepared for each element and measurements are sequentially performed. If the change of the measurement condition is input in advance to the control unit, a plurality of elements can be automatically analyzed.

Measurement Example 2 The apparatus having the measurement system shown in FIG. 4 is started according to the following procedure. (A) The state of the measurement system is adjusted in the same manner as (A) to (D) of Measurement Example 1. (B) In the analysis of arsenic, the flow rate of each liquid sending pump is adjusted so as to obtain the optimum reagent concentration. For example, the flow ratio of the reducing agent feed pumps 14h and 14i is set to 1: 6, and 1%
The NaBita ₄ for feeding to the reaction section 13 through the pipe 14d. At this time, control is performed so that the total flow rate of the pipe 14d is 2 ml / min (specifically, the flow rate of the reducing agent is 0.29 ml / min, and the amount of diluting water is 1.71 ml / min). (C) Similarly, the flow rate ratio between the feed pumps 14f and 14g in the acid supply section is set to 1: 2, and 6ΜHCl is passed through the pipe 14d.
Feed at 2 ml / min. (D) Also, a 40% KI solution as a preliminary reducing agent is sent to the preliminary reaction section 13a at a rate of 2 ml / min.

(E) This state is maintained for a specified time (for example, 3 minutes) to stabilize the state of the apparatus. On the other hand, in the detector, the hollow cathode lamp of the measuring means is set at the optimum position on the measuring optical path, and the measuring wavelength is automatically set to the resonance line wavelength (193.7 nm) at which the highest sensitivity of arsenic is obtained. (F) After the measurement system is stabilized, the measurement of the standard solution and the sample solution is sequentially performed. Note that the sample solution is sequentially introduced into the measurement system by a carrier (eg, water) in an amount of 500 μl under standard conditions in the sample introduction section. After each sample solution is measured, absorbance is calculated
(Peak height or peak area), and the concentration of the measurement element (metalloid element, etc.) in the sample solution is calculated based on the measured absorbance. The result is displayed on a display device connected to the control unit and recorded in the control unit.

(G) The necessity of re-measurement is determined, and a re-measurement is performed for a necessary sample. The procedure of the re-measurement is basically the same as in Measurement Example 1 except that the acid concentration and the reducing agent concentration are adjusted by adjusting the flow rate of the liquid sending pump. For example, re-measurement is performed by increasing the amount of dilution water and sequentially decreasing the concentrations of the acid and the reducing agent by half. The acid supply amount or the reducing agent supply amount may be reduced without changing the dilution water amount. Alternatively, re-measurement is performed by sequentially increasing the concentrations of the acid and the reducing agent by reducing the amount of dilution water. The acid supply amount or the reducing agent supply amount may be increased without changing the dilution water amount.

Example 1 Arsenic was measured using the measurement system shown in FIG. As a result of creating a calibration curve using the arsenic standard solution, the linear range of the calibration curve
(Dynamic Resin) is 0.03 to 0.2 ppm (absorbance: 0.030
From 0.250). The measurement at this time was performed under standard conditions (sample injection amount 500 μl, hydrochloric acid concentration 3 M, sodium borohydride 1%). Table 1 shows the results obtained by automatically measuring sample solutions having various arsenic concentrations. The measurement was performed in the order of the measurement number. The-mark in the absorbance column is a measurement omitted,
ND shows what could not be detected by the measurement. Also,
OV. Indicates that the measurement range was deviated. In this measurement system, each solution having a concentration of 1, 2, 3, or 6 M can be supplied as hydrochloric acid, and each solution having a concentration of 0.5, 1.0, 2.0, or 5.0% can be supplied as sodium borohydride. Were set to be supplied respectively.

[0033]

[Table 1]

Example 2 Arsenic was measured using the measurement system shown in FIG. As a result of creating a calibration curve using the arsenic standard solution, the linear range of the calibration curve
(Dynamic Resin) was 0.03 to 0.2 ppm (absorbance: 0.030 to 0.250). The measurement at this time was performed under standard conditions (sample injection amount 500 μl, hydrochloric acid concentration 3 M, sodium borohydride 1%). Table 2 shows the results of automatically measuring sample solutions having various arsenic concentrations. The measurement was performed in the order of the measurement number.
The-mark in the absorbance column is a value for which measurement was omitted, and ND
Indicates those which could not be detected by the measurement. Also, OV.
Indicates that the measurement range has been deviated. In this measurement system, it was set so that a 12M solution as hydrochloric acid and 5.0% as sodium borohydride could be supplied.

[0035]

[Table 2]

In Tables 1 and 2, the arsenic concentration was 0.0
When a sample on the order of 1 ppm is measured under the conditions of measurement number 1, it is below the detection limit and cannot be measured (ND).
Therefore, when the sample injection amount was doubled (1000 μm) and measured (measurement number 8), a measured value (0.009) was obtained. However, since this was within the range of the calibration curve limit, the hydrochloric acid concentration was further increased by 2%. The measurement value (measurement number 9) was increased by a factor of 6 (6M) to obtain a measurement value (0.034). With respect to a sample having an arsenic concentration of 0.1 ppm order, it was possible to measure within the range of the calibration curve under the condition of measurement number 1. For the sample having an arsenic concentration on the order of 1 ppm, the calibration curve limit was exceeded under the conditions of measurement numbers 1 and 2, but the measurement value (0.28) was obtained under the condition of measurement number 3. However, this value is near the outside of the calibration curve.
(Measurement number 4) and a measurement value (0.143) were obtained. Note that the sample having an arsenic concentration of 0.001 ppm was not detectable under any of the measurement conditions.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a measurement system of the apparatus of the present invention.

FIG. 2 is a conceptual diagram showing a configuration example of a reagent introduction unit.

FIG. 3 is a conceptual diagram showing a configuration example of a reagent introduction unit.

FIG. 4 is a conceptual diagram showing a configuration example of a reagent introduction unit.

[Explanation of symbols]

11: sample introduction part, 12: autosampler, 13: reaction part, 14: reagent introduction part, 15: gas-liquid separation part, 16: detection part

Claims (8)

[Claims] 1. A flow analyzer in which a sample introduction section, a reagent introduction section, a reaction section, a gas-liquid separation section, and a detection section are sequentially and integrally connected by a pipe line. A loop for holding is provided, and a sample solution in the loop is introduced into the reaction section through a conduit by a carrier, a reagent introduction section is connected to the reaction section, and an acid supply section is connected to the reagent introduction section. And a reducing agent supply unit are provided, respectively, and the hydride gas of the element to be analyzed in the sample is generated by the acid and the reducing agent supplied to the reaction unit, and the sample liquid containing the hydride gas is supplied to the reaction unit. To the gas-liquid separator,
A hydride generation analyzer, wherein a hydride gas separated into gas and liquid by an inert gas introduced into the gas-liquid separation unit is guided to a detection unit for analysis. 2. A pre-reducing agent supply section is provided in the reagent introduction section together with an acid supply section and a reducing agent supply section, and the acid and the reducing agent are supplied after the pre-reducing agent is supplied to the sample liquid in the reaction section. The analyzer according to claim 1. 3. The analyzer according to claim 1, wherein the acid supply section holds acids having different concentrations, and the acid concentration is selected according to the sample solution. 4. The analyzer according to claim 1, wherein the reducing agent supply section holds reducing agents having different concentrations, and the concentration of the reducing agent is selected according to the sample liquid. 5. The analyzer according to claim 1, wherein the acid supply unit is provided with an acid and a dilution water supply unit, and the acid is diluted to a predetermined concentration by the dilution water and supplied to the reaction unit. . 6. The reducing agent supply unit is provided with a supply unit for a reducing agent and a dilution water, respectively, and the reducing agent is diluted to a predetermined concentration by the dilution water and supplied to the reaction unit.
The analyzer according to claim 1. 7. The pre-reducing agent supply unit holds a plurality of pre-reducing agents, and selects one of them according to a sample liquid.
An analyzer according to any one of claims 1 to 6. 8. A control circuit for integrally controlling the operations of a sample introduction unit, a reagent introduction unit, a reaction unit, a gas-liquid separation unit, and a detection unit is provided, and a series of operations from introduction of a sample solution to analysis is performed. The analyzer according to any one of claims 1 to 7, which is performed automatically.