CHEMICALLY AMPLIFIED CURRENT RESPONSE OF VITAMIN-C BASED ON THE CYCLIC REACTION BETWEEN L-ASCORBIC-ACID AND DEHYDROASCORBIC ACID, USING DITHIOTHREITHOL AND ASCORBATE OXIDASE

被引：20

作者：

UCHIYAMA, SC

机构：

[1] Department of Environmental Engineering, Saitama Institute of Technology, Okabe, Saitama, 369-02

来源：

TALANTA | 1992年 / 39卷 / 10期

关键词：

D O I：

10.1016/0039-9140(92)80239-A

中图分类号：

O65 [分析化学];

学科分类号：

070302 ; 081704 ;

摘要：

A cyclic reaction between the reduced and the oxidized forms of vitamin C takes place by combining the ascorbate oxidase reaction and the reduction Of L-ascorbic acid to dehydroascorbic acid by dithiothreithol. L-Ascorbic acid is oxidized by the dissolved oxygen and its consumption is not compensated by the chemical regeneration of L-ascorbic acid from dehydroascorbic acid. The dissolved oxygen then continues to decrease during the cyclic reaction, consequently, the decrease of the reduction current of oxygen is amplified. The amplification factor of 5 x 10(-5)M L-ascorbic acid at 5 x 10(-3)M dithiothreithol and pH 7.5 was found to be 10.6 when enzyme activity is 0.64 units/ml and the reaction time is 10 min.

引用

页码：1289 / 1292

页数：4

共 9 条

[1] ASCORBATE ELECTRODE FOR DETERMINATION OF L-ASCORBIC-ACID IN FOOD [J].