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

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).

1 - 9 . (canceled) 
     
     
         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 in the absence of any enzyme responsive to creatinine, to cause creatinine contained in the urine to reduce the metal complex;   (b) electrochemically 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 - 24 . (canceled)