Solution quantitative analysis apparatus, quantitative analysis methods, and nuclear reactor water quality control system

• US 5,186,798 A
• Filed: 04/26/1990
• Issued: 02/16/1993
• Est. Priority Date: 12/11/1987
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Kikuchi, Eiji, Mabuchi, Katsumi, Takahashi, Takuya, Sakai, Masanori, Ohsumi, Katsumi, Ohnaka, Noriyuki
• Primary Examiner(s): Tung, T.
• Application Number:
  US07/514,970
• Time in Patent Office: 1,027 Days
• Field of Search: 204/153.1, 204/400, 204/412, 204/434
• US Class Current: 205/782.5
• CPC Class Codes: G01N 27/42 Measuring deposition or liberation of materials from an electrolyte; Coulometry, i.e. measuring coulomb-equivalent of material in an electrolyte

Abstract

This invention comprises electrochemical analytical devices capable of performing electrolysis in multiple pulse modes. It relates to a method of quantitative analysis and equipment for performing quantitative analysis which uses a combination of these pulse modes to realize the measurement of concentrations of multiple substances to be measured, occurring in the test solution to be measured and also a nuclear reactor water quality control system employing such a quantitative analysis method.

Claims

1. A solution quantitative analysis apparatus comprising:

an electrolytic cell for electrolyzing a solution containing a plurality of chemical species to be analyzed, the electrolytic cell including a working electrode, a counter electrode, and a reference electrode;

means for producing a plurality of mutually different voltage-time waveform signals corresponding to a plurality of mutually different voltammetry modes equal in number to the plurality of chemical species to be analyzed;

means for separately applying the plurality of voltage-time waveform signals to the working electrode, thereby performing the plurality of voltammetry modes, wherein each of the plurality of voltage-time waveform signals electrolyzes the solution, thereby producing a respective electrolysis current having one of a limiting current and a peak current depending on the corresponding voltammetry mode;

means for measuring the one of a limiting current and a peak current of the electrolysis current produced by each of the plurality of voltage-time waveform signals; and

means for calculating respective concentrations of the plurality of chemical species to be analyzed on the basis of the measured ones of a limiting current and a peak current.

2. A quantitative analysis apparatus for simultaneous analysis of H₂ O₂ and one of H₂ and O₂ comprising:

an electrolytic cell for electrolyzing a solution containing H₂ O₂ and one of H₂ and O₂ to be analyzed, the electrolytic cell including a working electrode, a counter electrode, and a reference electrode;

means for producing two mutually different voltage-time waveform signals corresponding to two mutually different voltammetry modes equal in number to the H₂ O₂ and one of H₂ and O₂ to be analyzed;

means for separately applying the two voltage-time waveform signals to the working electrode, thereby performing the two voltammetry modes, wherein each of the two voltage-time waveform signals electrolyzes the solution, thereby producing a respective electrolysis current having one of a limiting current and a peak current depending on the corresponding voltammetry mode;

means for measuring the one of a limiting current and a peak current of the electrolysis current produced by each of the two voltage-time waveform signals; and

means for calculating respective concentrations of the H₂ O₂ and one of H₂ and O₂ to be analyzed on the basis of the measured ones of a limiting current and a peak current.

3. A quantitative analysis apparatus for simultaneous analysis of H₂, O₂, and H₂ O₂ comprising:

an electrolytic cell for electrolyzing a solution containing H₂, O₂, and H₂ O₂ to be analyzed, the electrolytic cell including a working electrode, a counter electrode, and a reference electrode;

means for producing three mutually different voltage-time waveform signals corresponding to three mutually different voltammetry modes equal in number to the H₂, O₂, and H₂ O₂ to be analyzed;

means for separately applying the three voltage-time waveform signals to the working electrode, thereby performing the three voltammetry modes, wherein each of the three voltage-time waveform signals electrolyzes the solution, thereby producing a respective electrolysis current having one of a limiting current and a peak current depending on the corresponding voltammetry mode;

means for measuring the one of a limiting current and a peak current of the electrolysis current produced by each of the three voltage-=time waveform signals; and

means for calculating respective concentrations of the H₂, O₂, and H₂ O₂ to be analyzed on the basis of the measured ones of a limiting current and a peak current.

4. A solution quantitative analysis apparatus comprising:

an electrolytic cell for electrolyzing a solution containing a plurality of chemical species to be analyzed, the electrolytic cell including a working electrode, a counter electrode, and a reference electrode;

means for producing a plurality of mutually different voltage-time waveform signals corresponding to a plurality of mutually different pulse voltammetry modes equal in number to the plurality of chemical species to be analyzed;

means for separately applying the plurality of voltage-time waveform signals to the working electrode, thereby performing the plurality of pulse voltammetry modes, wherein each of the plurality of voltage-time waveform signals electrolyzes the solution, thereby producing a respective electrolysis current having one of a limiting current and a peak current depending on the corresponding pulse voltammetry mode;

means for measuring the one of a limiting current and a peak current of the electrolysis current produced by each of the plurality of voltage-time waveform signals; and

means for calculating respective concentrations of the plurality of chemical species to be analyzed on the basis of the measured ones of a limiting current and a peak current.

5. A quantitative analysis apparatus for simultaneous analysis of H₂ O₂ and one of H₂ and O₂ comprising:

an electrolytic cell for electrolyzing a solution containing H₂ O₂ and one of H₂ and O₂ to be analyzed, the electrolytic cell including a working electrode, a counter electrode, and a reference electrode;

means for producing two mutually different voltage-time waveform signals corresponding to two mutually different pulse voltammetry modes equal in number to the H₂ O₂ and one of H₂ and O₂ to be analyzed;

means for separately applying the two voltage-time waveform signals to the working electrode, thereby performing the two pulse voltammetry modes, wherein each of the two voltage-time waveform signals electrolyzes the solution, thereby producing a respective electrolysis current having one of a limiting current and a peak current depending on the corresponding pulse voltammetry mode;

means for measuring the one of a limiting current and a peak current of the electrolysis current produced by each of the two voltage-time waveform signals; and

means for calculating respective concentrations of the H₂ O₂ and one of H₂ and O₂ to be analyzed on the basis of the measured ones of a limiting current and a peak current.

6. A quantitative analysis apparatus according to claim 5, wherein the means for producing two mutually different voltage-time waveform signals produces a voltage-time waveform signal corresponding to a normal pulse voltammetry mode producing an electrolysis current having a limiting current, and produces a voltage-time waveform signal corresponding to a differential pulse voltammetry mode producing an electrolysis current having a peak current.

7. A quantitative analysis apparatus for simultaneous analysis of H₂, O₂, and H₂ O₂ comprising:

an electrolytic cell for electrolyzing a solution containing H₂, O₂, and H₂ O₂ to be analyzed, the electrolytic cell including a working electrode, a counter electrode, and a reference electrode;

means for producing three mutually different voltage-time waveform signals corresponding to three mutually different pulse voltammetry modes equal in number to the H₂, O₂, and H₂ O₂ to be analyzed;

means for separately applying the three voltage-time waveform signals to the working electrode, thereby performing the three pulse voltammetry modes, wherein each of the three voltage-time waveform signals electrolyzes the solution, thereby producing a respective electrolysis current having one of a limiting current and a peak current depending on the corresponding pulse voltammetry mode;

means for measuring the one of a limiting current and a peak current of the electrolysis current produced by each of the three voltage-time waveform signals; and

means for calculating respective concentrations of the H₂, O₂, and H₂ O₂ to be analyzed on the basis of the measured ones of a limiting current and a peak current.

8. A solution quantitative analysis apparatus comprising:

an electrolytic cell for electrolyzing a solution containing a plurality of chemical species to be analyzed, the electrolytic cell including a working electrode, a counter electrode, and a reference electrode;

a potentiostat for applying a voltage to the working electrode; and

a CPU including;

means for producing a plurality of mutually different voltage-time waveform signals corresponding to a plurality of mutually different voltammetry modes equal in number to the plurality of chemical species to be analyzed;

means for supplying the plurality of voltage-time waveform signals to the potentiostat such that the potentiostat separately applies the plurality of voltage-time waveform signals to the working electrode, thereby performing the plurality of voltammetry modes, wherein each of the plurality of voltage-time waveform signals electrolyzes the solution, thereby producing a respective electrolysis current having one of a limiting current and a peak current depending on the corresponding voltammetry mode;

means for storing results of each of the plurality of voltammetry modes in the form of a relationship between an electrolysis current and a voltage which produced it;

means for measuring the one of a limiting current and a peak current of the electrolysis current produced by each of the plurality of voltage-time waveform signals on the basis of the results stored in the storing means; and

means for calculating respective concentrations of the plurality of chemical species to be analyzed on the basis of the measured ones of a limiting current and a peak current.

9. A solution quantitative analysis apparatus comprising:

an electrolytic cell for electrolyzing a solution containing a plurality of chemical species to be analyzed, the electrolytic cell including a working electrode, a counter electrode, and a reference electrode;

a potentiostat for applying a voltage to the working electrode; and

a CPU including;

means for producing a plurality of mutually different voltage-time waveform signals corresponding to a plurality of mutually different pulse voltammetry modes equal in number to the plurality of chemical species to be analyzed;

means for supplying the plurality of voltage-time waveform signals to the potentiostat such that the potentiostat separately applies the plurality of voltage-time waveform signals to the working electrode, thereby performing the plurality of mutually different pulse voltammetry modes, wherein each of the plurality of voltage-time waveform signals electrolyzes the solution, thereby producing a respective electrolysis current having one of a limiting current and a peak current depending on the corresponding pulse voltammetry mode;

means for storing results of each of the plurality of pulse voltammetry modes in the form of a relationship between an electrolysis current and a voltage which produced it;

means for measuring the one of a limiting current and a peak current of the electrolysis current produced by each of the plurality of voltage-time waveform signals on the basis of the results stored in the storing means; and

means for calculating respective concentrations of the plurality of chemical species to be analyzed on the basis of the measured ones of a limiting current and a peak current.

10. A quantitative analysis apparatus for simultaneous analysis of H₂ O₂ and one of H₂ and O₂ comprising:

an electrolytic cell for electrolyzing a solution containing H₂ O₂ and one of H₂ and O₂ to be analyzed, the electrolytic cell including a working electrode, a counter electrode, and a reference electrode;

a potentiostat for applying a voltage to the working electrode; and

a CPU including;

means for producing two mutually different voltage-time waveform signals corresponding to two mutually different voltammetry modes equal in number to the H₂ O₂ and one of H₂ and O₂ to be analyzed;

means for supplying the two voltage-time waveform signals to the potentiostat such that the potentiostat separately applies the two voltage-time waveform signals to the working electrode, thereby performing the two voltammetry modes, wherein each of the two voltage-time waveform signals electrolyzes the solution, thereby producing a respective electrolysis current having one of a limiting current and a peak current depending on the corresponding voltammetry mode;

means for storing results of each of the two voltammetry modes in the form of a relationship between an electrolysis current and a voltage which produced it;

means for measuring the one of a limiting current and a peak current of the electrolysis current produced by each of the two voltage-time waveform signals on the basis of the results stored in the storing means; and

means for calculating respective concentrations of the H₂ O₂ and one of H₂ and O₂ to be analyzed on the basis of the measured ones of a limiting current and a peak current.

11. A quantitative analysis apparatus for simultaneous analysis of H₂ O₂ and one of H₂ and O₂ comprising:

an electrolytic cell for electrolyzing a solution containing H₂ O₂ and one of H₂ and O₂ to be analyzed, the electrolytic cell including a working electrode, a counter electrode, and a reference electrode;

a potentiostat for applying a voltage to the working electrode; and

a CPU including;

means for producing two mutually different voltage-time waveform signals corresponding to two mutually different pulse voltammetry modes equal in number to the H₂ O₂ and one of H₂ and O₂ to be analyzed;

means for supplying the two voltage-time waveform signals to the potentiostat such that the potentiostat separately applies the two voltage-time waveform signals to the working electrode, thereby performing the two pulse voltammetry modes, wherein each of the two voltage-time waveform signals electrolyzes the solution, thereby producing a respective electrolysis current having one of a limiting current and a peak current depending on the corresponding voltammetry mode;

means for storing results of each of the two pulse voltammetry modes in the form of a relationship between an electrolysis current and a voltage which produces it;

means for measuring the one of a limiting current and a peak current of the electrolysis current produced by each of the two voltage-time waveform signals on the basis of the results stored in the storing means; and

means for calculating respective concentrations of the H₂ O₂ and one of H₂ and O₂ to be analyzed on the basis of the measured ones of a limiting current and a peak current.

12. A quantitative analysis apparatus for simultaneous analysis of H₂ O₂ and one of H₂ and O₂ comprising:

an electrolytic cell for electrolyzing a solution containing H₂ O₂ and one of H₂ and O₂ to be analyzed, the electrolytic cell including a working electrode, a counter electrode, and a reference electrode;

a potentiostat for applying a voltage to the working electrode; and

a CPU including;

means for producing a first voltage-time waveform signal corresponding to a normal pulse voltammetry mode and a second voltage-time waveform signal corresponding to a differential pulse voltammetry mode;

means for supplying the first and second voltage-time waveform signals to the potentiostat such that the potentiostat separately applies the first voltage-time waveform signal to the working electrode, thereby performing the normal pulse voltammetry mode, and the second voltage-time waveform signal to the working electrode, thereby performing the differential pulse voltammetry mode, wherein the first and second voltage-time waveform signals electrolyze the solution, thereby producing respective electrolysis currents respectively having a limiting current and a peak current;

means for storing results of the normal pulse voltammetry mode and the differential voltammetry mode in the form of a relationship between an electrolysis current and a voltage which produced it;

means for measuring the limiting current of the electrolysis current produced by the first voltage-time waveform signal and the peak current of the electrolysis current produced by the second voltage-time waveform signal on the basis of the results stored in the storing means; and

means for calculating respective concentrations of the H₂ O₂ and one of H₂ and O₂ to be analyzed on the basis of the measured limiting current and peak current.

13. A quantitative analysis apparatus for simultaneous analysis of H₂, O₂, and H₂ O₂ comprising:

an electrolytic cell for electrolyzing a solution containing H₂, O₂, and H₂ O₂ to be analyzed, the electrolytic cell including a working electrode, a counter electrode, and a reference electrode;

a potentiostat for applying a voltage to the working electrode; and

a CPU including;

means for producing three mutually different voltage-time waveform signals corresponding to three mutually different voltammetry modes equal in number to the H₂, O₂, and H₂ O₂ to be analyzed;

means for supplying the three voltage-time waveform signals to the potentiostat such that the potentiostat separately applies the three voltage-time waveform signals to the working electrode, thereby performing the three voltammetry modes, wherein each of the three voltage-time waveform signals electrolyzes the solution, thereby producing a respective electrolysis current having one of a limiting current and a peak current depending on the corresponding voltammetry mode;

means for storing results of each of the three voltammetry modes in the form of a relationship between an electrolysis current and a voltage which produced it;

means for measuring the one of a limiting current and a peak current of the electrolysis current produced by each of the plurality of voltage-time waveform signals on the basis of the results stored in the storing means; and

means for calculating respective concentrations of the H₂, O₂, and H₂ O₂ to be analyzed on the basis of the measured ones of a limiting current and a peak current.

14. A quantitative analysis apparatus according to claim 13, wherein the means for producing three mutually different voltage-time waveform signals produces three mutually different voltage-time waveform signals corresponding to three mutually different pulse voltammetry modes, and wherein the means for supplying the three voltage-time waveform signals to the potentiostat supplies the three voltage-time waveform signals to the potentiostat such that the potentiostat separately applies the three voltage-time waveform signals to the working electrode, thereby performing the three pulse voltammetry modes.

15. A method for performing quantitative analysis of a solution using an electrolytic cell for electrolyzing a solution containing a plurality of chemical species to be analyzed, the electrolytic cell including a working electrode, a counter electrode, and a reference electrode, the method comprising the steps of:

separately applying a plurality of mutually different voltage-time waveform signals to the working electrode for performing a corresponding plurality of mutually different voltammetry modes corresponding to the plurality of chemical species to be analyzed, wherein each of the plurality of voltage-time waveform signals electrolyzes the solution to produce a respective electrolysis current having one of a limiting current and a peak current depending on the corresponding voltammetry mode;

measuring the one of a limiting current and a peak current of the electrolysis current produced by each of the plurality of voltage-time waveform signals; and

calculating respective concentrations of the plurality of chemical species to be analyzed on the basis of the measured ones of a limiting current and a peak current.

16. A method according to claim 15, wherein the step of separately applying a plurality of mutually different voltage-time waveform signals to the working electrode includes applying a plurality of mutually different voltage-time waveform signals to the working electrode for performing a corresponding plurality of mutually different pulse voltammetry modes.

17. A method for performing simultaneous quantitative analysis of H₂, O₂, and H₂ O₂ using an electrolytic cell for electrolyzing a solution containing H₂, O₂, and H₂ O₂ to be analyzed, the electrolytic cell including a working electrode, a counter electrode, and a reference electrode, the method comprising the steps of:

separately applying three mutually different voltage-time waveform signals to the working electrode for performing three mutually different voltammetry modes, wherein each of the three voltage-time waveform signals electrolyzes the solution to produce a respective electrolysis current having one of a limiting current and a peak current depending on the corresponding voltammetry mode;

measuring the one of a limiting current and a peak current of the electrolysis current produced by each of the three voltage-time waveform signals; and

calculating respective concentrations of the H₂, O₂, and H₂ O₂ to be analyzed on the basis of the measured ones of a limiting current and a peak current.

18. A method according to claim 17, wherein the step of separately applying three mutually different voltage-time waveform signals to the working electrode includes applying threee mutually different voltage-time waveform signals to the working electrode for performing three mutually different pulse voltammetry modes.

19. A method for performing simultaneous quantitative analysis of H₂ O₂ and one of H₂ and O₂ using an electrolytic cell for electrolyzing a solution containing H₂ O₂ and one of H₂ and O₂ to be analyzed, the electrolytic cell including a working electrode, a counter electrode, and a reference electrode, the method comprising the steps of:

separately applying two mutually different voltage-time waveform signals to the working electrode for performing two mutually different voltammetry modes, wherein each of the two voltage-time waveform signals electrolyzes the solution to produce a respective electrolysis current having one of a limiting current and a peak current depending on the corresponding voltammetry mode;

measuring the one of a limiting current and a peak current of the electrolysis current produced by each of the two voltage-time waveform signals; and

calculating respective concentrations of the H₂ O₂ and one of H₂ and O₂ to be analyzed on the basis of the measured ones of a limiting current and a peak current.

20. A solution quantitative analysis apparatus for analysis of reactor water in a nuclear reactor having a primary water-based cooling system comprising:

an electrolytic cell for electrolyzing reactor water in at least one location in the primary water-based cooling system in the nuclear reactor, the reactor water containing a plurality of chemical species to be analyzed, the electrolytic cell including a working electrode, a counter electrode, and a reference electrode;

means for producing a plurality of mutually different voltage-time waveform signals corresponding to a plurality of mutually different voltammetry modes equal in number to the plurality of chemical species to be analyzed;

means for separately applying the plurality of voltage-time waveform signals to the working electrode, thereby performing the plurality of voltammetry modes, wherein each of the plurality of voltage-time waveform signals electrolyzes the reactor water, thereby producing a respective electrolysis current having one of a limiting current and a peak current depending on the corresponding voltammetry mode;

means for measuring the one of a limiting current and a peak current of the electrolysis current produced by each of the plurality of voltage-time waveform signals; and

means for calculating respective concentrations of the plurality of chemical species to be analyzed on the basis of the measured ones of a limiting current and a peak current.