【摘要】 报道了一种简便和灵敏的半胱氨酸含量测定的新方法 .利用半胱氨酸的还原性将磷钼杂多酸还原成磷钼杂多蓝 ,在 71 0 nm最大吸收波长处测其吸光度 ,吸光度与半胱氨酸的浓度在 0 .4～ 1 6 .0 m g/ L范围内呈线性关系 ,相关系数 r=0 .9990 ,方法检测限为 0 .2 mg/ L ,相对标准偏差 RSD=0 .91 % ,回收率为 98.5 %～ 1 0 2 .9% .该法应用于牛乳清样品中半胱氨酸含量的直接测定 ,结果满意更多还原

【Abstract】 A new simple and sensitive method is presented for spectrophotometric determination of cysteine with phosphorusmolybdenum heteropoly blue. The method is based on the reaction of phosphorusmolybdenum heteropoly acid with cysteine. The reactive product exhibits maximum absorption at 710 nm . At the optimal conditions , the absorptivity is proportional to cysteine(Cys) concentration in the range of 0.4 ～ 16.0 mg/L( r =0.999 0). The detection limit of 0.2 mg/L, the relative standard deviation of 0.91 %( n =6) and the recovery of 98.5 % ～ 102.9 % are given . The method has been applied to the determination of cysteine in bovine whey sample with satisfactory results.更多还原