γ-氨基丁酸碳糊电极电位法测定γ-氨基丁酸含量

Potentiometric Determination of γ-Aminobutyric Acid with γ-Aminobutyric Acid Modified Carbon Paste Electrode

制备了一种以邻二氮菲合铁配离子与γ-氨基丁酸形成的缔合物为电活性物的γ-氨基丁酸碳糊电极,并对其性能做了测定。结果显示该电极对γ-氨基丁酸有较好的能斯特响应。γ-氨基丁酸的线性范围为1.0×10-5～8.0×10-2 mol.L-1,极差电位为38mV.pc-1,测定下限(10S/N)为5.2×10-6 mol.L-1。电极用于糙米、青稞籽和茶叶中γ-氨基丁酸含量的测定,结果与分光光度法结果相符。

An association complex formed between coordination complex of Fe（ Ⅱ ）-o-phenanthroline and γ- aminobutyric add was prepared and used as electroactive material in the preparation of γ-aminobutyric acid modified carbon paste electrode, and the electrochemical properties of this modified electrode were studied. Good response of this electrode against γ-aminobutyric acid was obtained giving linearity range from 1.0×10^-5 to 8. 0×10^-2 mol·L^-1, with a slope of 38 mV·pc^-1 and lower limit of determination （10S/N） of 5.2×10^-6mol·L^-1. The modified electrode was used in the potentiometric determination of γ-aminobutyric acid in sample of brown rice, highland barly and green tea, the results obtained were checked quite well with those found by speetrophotometry.