L-半胱氨酸修饰电极测定维生素C的方法研究

Study on determination of Vitamin C by L-cysteine modified electrode

研究了L-半胱氨酸修饰电极的制备方法和其电化学行为,并用于维生素C的测定,发现该电极对VC有明显的电催化作用,在pH=10.0的NH4Cl-NH3·H2O缓冲溶液中,VC在L-半胱氨酸修饰电极上产生一灵敏的氧化峰,峰电流与VC的浓度在1.0×10-3￣1.0×10-6mol/L的范围内呈良好的线形关系,相关系数为0.9962,其最低检测限可达1.0×10-6mol/L,与紫外光谱法测定的结果一致。

The method of making the L-cysteine modified electrode and its electrochemical behaviour were studied, and the electrode was used for the determination of Vitamin C. It was found that the electrode had an obvious electric catalyzing effect on Vitamin C. Vitamin C produced on the L-cysteine modified electrode an oxidizing peak sensitively, the value of peak current increased linearly with the concentration of Vitamin C in the range of 1.0 ×10^-3 - 1.0 ×10^-6 mol· L^-1 in an NHaCl-NH3·H2O buffer solution （pH = 10.0） . The related coefficient was 0.9962, the detection limit was 1.0 ×10^-6 mol· L^-1, and the results obtained were the same as those of the ultraviolet spectrometry.