| 摘要 |
PURPOSE:To make it possible to determine lactic acid and including L-lactic acid and D-lactic acid through a simple operation by detecting variation of concentration electrochemically using an enzyme having a function for racemizing lactic acid and an enzyme having function for oxidizing lactic acid. CONSTITUTION:A carboxymethylcellulose(CMC) layer of hydrophilic polymer is formed on an electrode system comprising a working electrode 4 and a pair electrode 5 formed on a substrate 1. An enzyme having function for oxidizing lactic acid, i.e., lactic acid oxidase, and an enzyme having function for racemizing lactic acid, i.e., lactic acid racemase, are dissolved into a phosphoric acid buffer and developed onto a CMC layer and then it is dried to form a reaction layer 11. When the reaction layer 11 is dissolved into a sample liquid, only one of L-lactic acid or D-lactic acid is oxidized by the lactic acid oxidase and the other lactic acid not oxidized by the enzyme is converted, by the lactic acid racemase, into D-lactic acid or L-lactic acid being oxidized by enzyme thus allowing simultaneous determination of L-lactic acid and D-lactic acid. |
