Methods:The assay was based on precolumn derivatization of cystine(Cys)with 2,4-dinitrofluorobenzen(DNFB) in the phosphate buffer system(pH9.5),the quantitative analysis was performed with external standard under the optimal conditions.

• 方法:在碱性条件下；2；4-二硝基氟苯(DNFB)与胱氨酸反应生成 DNFB 氨基酸衍生物；在四硼酸钠缓冲液(pH 9.；8)中电泳分离；电压28kV；检测波长340nm。