酶电极—停流流动注射分析法测定L—谷氨酸

Determination of L-Glutamic Acid with Enzyme Electrode-Stopped Flow Injection Analysis Method

本文将清洗流通型谷氨酸脱羧酶电极与停流流动注射分析相结合,使整个分析具有省时、省试剂和便于自动化等特点。酶电极由作为pH敏感的铱电极和一个允许每次测样后置换内充液的样品池所组成。它克服了503型CO_2电极为基底电极的酶电极回洗能力差的缺点。与503型酶电极—停流流动注射分析相比,清洗速度快4倍,节约含昂贵的PLP试剂12倍,并能实现自动连续测定。测定标样(浓度为500～4000mg/L,n=6)的RSD<4％,RE<3％;测定稀释25倍的发酵液(C_谷=740.2mg/L),RSD<2％,加标回收率为90～99％。

A combination method of Washing Flow Model glutamate decarboxylase electrode and stopped flow injection analysis for determination of glutamic acid is described. It made whole analysis fast,cost-effective and easy for automation. The enzyme electrode is constructed with a Ir-electrode as the pH sensor and a new elec trode sample cell unit,allowing easy change of the internal filling solution after every assay. So the shortcoming for those enzyme electrodes in which Model 503 CC2 electrode i.s used as base electrode is difficult to reach base line recovery. Comparing with Model 503 enzyme electrode-slopped flow injection analysis, the washing rate is 4 fold faster, the requirement of expensive reagent PLP is 12 fold less and it has capability to realize automatic determination. The RSD and RE for determination of standard solutions arc<4 and <3% respectively. The RSD for determination of diluted fermentation solutioms<2%, the recovery is 90-99% in the concentration range 500-4000mg/L(n =6).