硅钼杂多酸示波极谱法测定抗坏血酸

Single Sweep Polarographic Determination of Ascorbic Acid Based on Its Reaction With 12-Molybdosilicate

本文研究了硅钼杂多酸与抗坏血酸的反应,发现其产物在示波极谱上于～1.12V(vs.SCE)产生灵敏吸附波,导数波高与抗坏血酸浓度在1×10^(-7)mol/L～4×10^(-5)mol/L有线性关系。检测限为5×10^(-8)mol/L。本法应用于针剂,片剂及柑桔中抗坏血酸的测定,得到满意结果。

A new method for the determination of trace amounts of ascorbic acid has been described, based on the measurement of substance produced by the reaction of ascorbic acid with 12-molybdosilicate, which can be strongly adsorbed on DME and reduced with a sensitive wave at -1.12V (vs.SCE) in. NH_3-NH_4Cl buffer solution (pH9.9). The derivative peak height is proportional to the concentration of ascorbic acid over the range of 1×10^(-7)～4×10^(-3)mol/L, and the detection limit is 5×10^(-8)mol/L. The procedure has been used for the determination of vitamin C in different kinds of samples with satisfactory results.