Method, device and apparatus for measuring the concentration of creatinine, and method, device and apparatus for measuring the amount of salt in urine using the same

Abstract

A method for measuring the concentration of creatinine includes the steps of: (A) mixing a sample containing creatinine with a creatinine quantitative reagent including 1-methoxy-5-methylphenazinium in the absence of picric acid and any enzyme responsive to creatinine, to cause the creatinine to reduce the 1-methoxy-5-methylphenazinium; (B) electrochemically or optically measuring the amount of the 1-methoxy-5-methylphenazinium reduced in the step (A); and (C) determining the concentration of the creatinine contained in the sample from the amount of the reduced 1-methoxy-5-methylphenazinium measured in the step (B).

1 - 11 . (canceled) 
     
     
         12 . A method for measuring an amount of salt, comprising the steps of:
 (a) mixing urine, which is a sample, with a creatinine quantitative reagent including 1-methoxy-5-methylphenazinium in the absence of picric acid and any enzyme responsive to creatinine, to cause creatinine contained in the urine to reduce the 1-methoxy-5-methylphenazinium;   (b) electrochemically or optically measuring an amount of the 1-methoxy-5-methylphenazinium reduced in the step (a);   (c) measuring an electrical property of the urine; and   (d) determining a value reflecting an amount of salt excreted into the urine from the amount of the reduced 1-methoxy-5-methylphenazinium measured in the step (b) and the electrical property measured in the step (c).   
     
     
         13 . The method for measuring an amount of salt in accordance with  claim 12 , wherein the step (c) is performed before the step (a). 
     
     
         14 . The method for measuring an amount of salt in accordance with  claim 12 , wherein the step (c) is performed after the step (b) and before the step (d). 
     
     
         15 . 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 including 1-methoxy-5-methylphenazinium and disposed in the sample holding space; and   two or more electrodes disposed in the sample holding space, or an optical measurement window disposed in the sample holding space.   
     
     
         16 . The device for measuring a concentration of creatinine in accordance with  claim 15 , further comprising a phosphate buffer in the sample holding space. 
     
     
         17 . The device for measuring a concentration of creatinine in accordance with  claim 16 , further comprising an electrolyte salt of a monovalent anion in the sample holding space. 
     
     
         18 . 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 including 1-methoxy-5-methylphenazinium and disposed in the first 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.   
     
     
         19 . The device for measuring an amount of salt in accordance with  claim 18 , further comprising two or more electrodes in the first sample holding space. 
     
     
         20 . 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; and a creatinine quantitative reagent including 1-methoxy-5-methylphenazinium and disposed in the sample holding space;   a measurement system for electrochemically or optically measuring an amount of the 1-methoxy-5-methylphenazinium 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 1-methoxy-5-methylphenazinium measured by the measurement system.   
     
     
         21 . The apparatus for measuring a concentration of creatinine in accordance with  claim 20 ,
 wherein the device for measuring the concentration of creatinine further includes two or more electrodes in the sample holding space,   the measurement system includes: 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.   
     
     
         22 . The apparatus for measuring a concentration of creatinine in accordance with  claim 20 , wherein the measurement system includes:
 a light source for emitting light to the sample holding space of the device for measuring the concentration of creatinine mounted in the measuring device mounting port; and   a light receiver for detecting the light transmitted through the sample holding space or the light reflected by 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 . 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 including 1-methoxy-5-methylphenazinium and disposed in the first 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 1-methoxy-5-methylphenazinium 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 into the urine from the amount of the reduced 1-methoxy-5-methylphenazinium measured by the first measurement system and the electrical property measured by the second measurement system.