硅钼杂多酸单扫示波极谱法测定半胱氨酸

Single Sweep Oscilloscopic polarography Determination of Cysteine Based on its Reaction with 12-Molybdosilicate

研究了硅钼杂多酸与半胱氨酸的反应，其产物在氨—氯化铵缓冲介质中，于滴汞电极上，在Ｅｐａ≈－０．９６Ｖ（ＶＳ．ＳＣＥ）处，产生灵敏吸附波。其阳极化导数波高与半胱氨酸浓度在１×１０－７～５×１０－５ｍｏｌ／Ｌ呈线性关系，检测限为５×１０－８ｍｏｌ／Ｌ。本法对混合样品中半胱氨酸的测定，回收率在９８．８％～１０１．２％之间变化，相对标准偏差为０．６％～１．１３％。

A new method for the determination of trace amounts of cysteine has been reported. The method is base on measurement of the substace produced by the reaction of cysteine of the substace produced by the reaction of cysteine with 12-molybdosilicate,which can be strongle absorbed on DME and produced a anodic wave at -9.6v(Vs.SCE) in NH 3-NH 4Cl buffer solution (pH=9.6). The derivative peak height is proportional to the concentration of cysteine in the range of 1×10 -7 ￣5×10 -5 mol/L.The detection limit of 5×10 -8 mol/L and a recovery of 98.8%￣101.2% and the relative standard deviation of 0.6%￣1.13% can be a chieved when this mothod is used to determine cystieine in mixed sample.