ELECTROCHEMICAL MEASUREMENT METHOD FOR CONCENTRATION OF LACTIC ACID

摘要

PURPOSE:To enhance reaction efficiency and to increase electrode output by using lactic acid oxidase as enzyme and allowing the lactic axid oxidase and octacyanotungsten ion to co-exist. CONSTITUTION:A working electrode 5 and a reference electrode 6 are immersed in a liquid 2 to be measured and the enzyme consisting of lactic acid as the substrate is made to exist on the electrode 5. The concn. of the lactic acid in the liquid 2 is measured in accordance with the value of the current generated between the two electrodes 5 and 6 as the enzyme reacts. The lactic axid oxidase is used as the enzyme. The octacyanotungsten W(CN)8<4-> ion is made to co-exist as an electron mediator in the lactic acid oxidase. The W(CN)8<3-> converted from the W(CN)8<4-> is electrochemically oxidized by the reaction of the lactic acid oxidase and the concn. of the lactic acid in the liquid 2 is measured in accordance with the oxidation current value. The reaction efficiency is thereby enhanced and the electrode output is increased.