METHOD, DEVICE AND APPARATUS FOR MEASURING THE CONCENTRATION OF CREATININE, AND METHOD, DEVICE AND APPARATUS FOR MEASURING THE AMOUNT OF SALT USING THE SAME

• US 20100159606A1
• Filed: 03/04/2010
• Published: 06/24/2010
• Est. Priority Date: 05/16/2008
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Fukunaga, Atsushi, NAKAMINAMI, Takahiro, Kashiwada, Kouji
• Granted Patent: US 7,816,145 B2
• Time in Patent Office: Days
• US Class Current: 436/73
• CPC Class Codes: C12Q 1/34 involving hydrolase
• CPC Class Codes: G01N 21/80 Indicating pH value
• CPC Class Codes: G01N 33/5302 Apparatus specially adapted for immunological test procedures
• CPC Class Codes: G01N 33/70 involving creatine or creatinine
• CPC Class Codes: Y10T 436/14 Heterocyclic carbon compound [i.e. , O, S, N, Se, Te, as only ring hetero atom]
• CPC Class Codes: Y10T 436/145555 Hetero-N
• CPC Class Codes: Y10T 436/147777 Plural nitrogen in the same ring [e.g., barbituates, creatinine, etc.]

Abstract

A method for measuring a concentration of creatinine includes the steps of: (A) mixing a sample containing creatinine with a creatinine quantitative reagent containing a metal complex of at least one of hexacyanoferrate and hexacyanoruthenate in the absence of picric acid and any enzyme responsive to creatinine, to cause the creatinine to reduce the metal complex; (B) electrochemically or optically measuring the amount of the metal complex reduced in the step (A); and (C) determining the concentration of the creatinine contained in the sample from the amount of the reduced metal complex measured in the step (B).

Claims

1. A method for measuring a concentration of creatinine, comprising the steps of:

(A) mixing a sample containing creatinine with a creatinine quantitative reagent containing a metal complex of at least one of hexacyanoferrate and hexacyanoruthenate in the absence of picric acid and any enzyme responsive to creatinine, to cause the creatinine to reduce the metal complex;

(B) electrochemically or optically measuring an amount of the metal complex reduced in the step (A); and

(C) determining a concentration of the creatinine contained in the sample from the amount of the reduced metal complex measured in the step (B).

2. The method for measuring a concentration of creatinine in accordance with claim 1, wherein after the mixing in the step (A), the sample has a pH of 2.5 or more and 7 or less.

3. The method for measuring a concentration of creatinine in accordance with claim 1, wherein after the mixing in the step (A), the sample has a pH of 3 or more and 6 or less.

4. The method for measuring a concentration of creatinine in accordance with claim 1, wherein in the step (A), the sample is further mixed with a phosphate buffer.

5. The method for measuring a concentration of creatinine in accordance with claim 1, wherein in the step (A), the sample is further mixed with a phosphate buffer so that a pH of the sample is adjusted to 5 to 6.

6. The method for measuring a concentration of creatinine in accordance with claim 1, wherein in the step (A), the sample is further mixed with a cationic hydrophilic polymer.

7. The method for measuring a concentration of creatinine in accordance with claim 6, wherein the cationic hydrophilic polymer is cationic guar gum.

8. The method for measuring a concentration of creatinine in accordance with claim 1,

wherein the step (B) comprises the steps of:

(D) bringing the sample into contact with two or more electrodes and applying a voltage between the two electrodes; and

(E) detecting a current value or an amount of electric charge flowing between the two electrodes, and

in the step (C), the concentration of the creatinine contained in the sample is determined from the current value or the amount of electric charge detected in the step (E).

9. The method for measuring a concentration of creatinine in accordance with claim 1,

wherein the step (B) comprises the steps of:

(F) irradiating the sample with light; and

(G) detecting the light transmitted through the sample or the light reflected by the sample, and

in the step (C), the concentration of the creatinine contained in the sample is determined from an intensity of the transmitted light or the reflected light detected in the step (G).

10. A method for measuring an amount of salt, comprising the steps of:

(a) mixing urine, which is a sample, with a creatinine quantitative reagent containing a metal complex of at least one of hexacyanoferrate and hexacyanoruthenate in the absence of picric acid and any enzyme responsive to creatinine, to cause creatinine contained in the urine to reduce the metal complex;

(b) electrochemically or optically measuring an amount of the metal complex reduced in the step (a);

(c) measuring an electrical property of the urine; and

(d) determining a value reflecting an amount of salt excreted in the urine from the amount of the reduced metal complex measured in the step (b) and the electrical property measured in the step (c).

11. The method for measuring an amount of salt in accordance with claim 10, wherein the step (c) is performed before the step (a).

12. The method for measuring an amount of salt in accordance with claim 10, wherein the step (c) is performed after the step (b) and before the step (d).

13. The method for measuring an amount of salt in accordance with claim 10, wherein in the step (a), the sample is further mixed with a phosphate buffer so that a pH of the sample is adjusted to 5 to 6.

14. The method for measuring an amount of salt in accordance with claim 10, wherein in the step (a), the sample is further mixed with a cationic hydrophilic polymer.

15. The method for measuring an amount of salt in accordance with claim 14, wherein the cationic hydrophilic polymer is cationic guar gum.

16. A device for measuring a concentration of creatinine, comprising:

a sample holding space for holding a sample containing creatinine in the absence of picric acid and any enzyme responsive to creatinine;

a sample inlet for introducing the sample into the sample holding space, the sample inlet communicating with the sample holding space;

a creatinine quantitative reagent disposed in the sample holding space, the reagent containing a metal complex of at least one of hexacyanoferrate and hexacyanoruthenate; and

two or more electrodes disposed in the sample holding space or an optical measurement window disposed on the sample holding space.

17. The device for measuring a concentration of creatinine in accordance with claim 16, further comprising a phosphate buffer in the sample holding space.

18. The device for measuring a concentration of creatinine in accordance with claim 16, further comprising a cationic hydrophilic polymer in the sample holding space.

19. The device for measuring a concentration of creatinine in accordance with claim 18, wherein the cationic hydrophilic polymer is cationic guar gum.

20. A device for measuring an amount of salt, comprising:

a first sample holding space for holding urine, which is a sample, in the absence of picric acid and any enzyme responsive to creatinine;

a first sample inlet for introducing the urine into the first sample holding space, the first sample inlet communicating with the first sample holding space;

a creatinine quantitative reagent disposed in the first sample holding space, the reagent containing a metal complex of at least one of hexacyanoferrate and hexacyanoruthenate;

two or more electrodes disposed in the first sample holding space or an optical measurement window disposed on the sample holding space,

a second sample holding space for holding the urine;

a second sample inlet for introducing the urine into the second sample holding space, the second sample inlet communicating with the second sample holding space; and

two or more electrodes disposed in the second sample holding space.

21. An apparatus for measuring a concentration of creatinine, comprising:

a measuring device mounting port for mounting a device for measuring a concentration of creatinine, the device comprising;

a sample holding space for holding a sample containing creatinine in the absence of picric acid and any enzyme responsive to creatinine;

a sample inlet for introducing the sample into the sample holding space, the sample inlet communicating with the sample holding space;

a creatinine quantitative reagent disposed in the sample holding space, the reagent containing a metal complex of at least one of hexacyanoferrate and hexacyanoruthenate; and

two or more electrodes disposed in the sample holding space or an optical measurement window disposed on the sample holding space;

a measurement system for electrochemically or optically measuring an amount of the metal complex reduced by the creatinine in the sample holding space; and

an arithmetic unit for determining a concentration of the creatinine contained in the sample from the amount of the reduced metal complex measured by the measurement system.

22. The apparatus for measuring a concentration of creatinine in accordance with claim 21,

wherein the measurement system comprises:

a light source for emitting light to the sample holding space; and

a light receiver for detecting the light transmitted through the sample holding space or the light reflected in the sample holding space, and

the arithmetic unit determines the concentration of the creatinine contained in the sample from an intensity of the transmitted light or the reflected light detected by the light receiver.

23. The apparatus for measuring a concentration of creatinine in accordance with claim 21,

wherein the measurement system comprises:

a voltage application unit for applying a voltage between the two electrodes; and

a detector for detecting a current value or an amount of electric charge flowing between the two electrodes, and

the arithmetic unit determines the concentration of the creatinine contained in the sample from the current value or the amount of electric charge detected by the detector.

24. An apparatus for measuring an amount of salt, comprising:

a measuring device mounting port for mounting a device for measuring an amount of salt, the device comprising;

a first sample holding space for holding urine, which is a sample, in the absence of picric acid and any enzyme responsive to creatinine;

a first sample inlet for introducing the urine into the first sample holding space, the first sample inlet communicating with the first sample holding space;

a creatinine quantitative reagent disposed in the first sample holding space, the reagent containing a metal complex of at least one of hexacyanoferrate and hexacyanoruthenate;

two or more electrodes disposed in the first sample holding space or an optical measurement window disposed on the sample holding space;

a second sample holding space for holding the urine;

a second sample inlet for introducing the urine into the second sample holding space, the second sample inlet communicating with the second sample holding space; and

two or more electrodes disposed in the second sample holding space;

a first measurement system for electrochemically or optically measuring an amount of the metal complex reduced by the creatinine in the first sample holding space;

a second measurement system for measuring an electrical property of the urine in the second sample holding space; and

an arithmetic unit for determining a value reflecting an amount of salt excreted in the urine from the amount of the reduced metal complex measured by the first measurement system and the electrical property measured by the second measurement system.