基于酶放大和安培检测的L-乳酸流动注射分析

Flow injection analysis of L-lactate with enzyme amplification and amperometric detection.

作者信息

Asouzu M U, Nonidez W K, Ho M H

机构信息

Department of Chemistry, University of Alabama, Birmingham 35294.

出版信息

Anal Chem. 1990 Apr 1;62(7):708-12. doi: 10.1021/ac00206a012.

DOI:10.1021/ac00206a012

PMID:2327587

Abstract

A flow injection analysis method for the determination of the lactate anion with enzyme amplification and amperometric detection is described. The system utilizes an oxygen electrode for measurement of changes in the oxygen concentration in the flow stream. Two enzymes, lactate oxidase and lactate dehydrogenase, were randomly coimmobilized on aminopropyl controlled-pore glass (AMP-CPG) and packed into a reactor. beta-NADH was used as a coenzyme for the regeneration of lactate from pyruvate. The experimental conditions for the determination of the lactate anion were studied for this system by the simplex and the univariant methods. The results obtained under these two conditions were compared. The simplex experimental condition yielded a calibration curve whose linear portion had a slope that was 1.2 times greater than that of the linear portion of the curve obtained under univariant conditions. The limit of detection under simplex condition was 1.19 x 10(-7) M vs 3.29 x 10(-7) M lactate under univariant conditions. The relative standard deviation obtained for this system at 6 x 10(-6) M lactate (n = 10) was about 2.5% under simplex conditions and 3.6% under univariant maximization conditions.

摘要

描述了一种用于测定乳酸根阴离子的流动注射分析方法，该方法采用酶放大和安培检测。该系统利用氧电极来测量流动相中氧浓度的变化。将乳酸氧化酶和乳酸脱氢酶这两种酶随机共固定在氨丙基可控孔径玻璃（AMP-CPG）上，并填充到反应器中。β-NADH用作辅酶，用于将丙酮酸再生为乳酸。通过单纯形法和单变量法研究了该系统测定乳酸根阴离子的实验条件。比较了在这两种条件下获得的结果。单纯形实验条件得到的校准曲线，其线性部分的斜率是单变量条件下所得曲线线性部分斜率的1.2倍。单纯形条件下的检测限为1.19×10⁻⁷ M，而单变量条件下乳酸的检测限为3.29×10⁻⁷ M。在6×10⁻⁶ M乳酸浓度下（n = 10），该系统在单纯形条件下获得的相对标准偏差约为2.5%，在单变量最大化条件下为3.6%。