半胱氨酸和胱氨酸的交流示波极谱滴定

AC Oscillopolarographic Titration of Cysteine and Cystine

在NH_3-NH_4CI缓冲溶液中,半胱氨酸在交流示波极谱图上具有敏锐的切口。利用镉盐与巯基生成硫醇盐衍生物的性质,进行交流示波极谱滴定,由半胱氨酸的切口消失指示滴定终点。胱氨酸在示波图上不具有切口。将其还原为半胱氨酸进行滴定。此方法简便、终点灵敏、结果准确。

Cystcine reacts with Cd to form (CyS)_2Cd in NH_3-NH_4Cl buffer solution. The disappearanceof cysteine incision can be used to indicate the end point of titration. Cystine hsn＇t the incision of dE/dt-E curve, but it can be reduced to cysteine by agent of NaHSO_3. The method is simple and accurate.