钛铁试剂-铜配合物荧光光谱法测定半胱氨酸

A Spectrofluorimetric Method for Cysteine Determination Using the Fluorescence System of Complex Between Tiron and Cu(II)

采用荧光光谱法和紫外-可见吸收光谱法研究了pH8．0的B—R缓冲溶液中L-半胱氨酸与钛铁试剂-铜配合物的作用过程。研究发现，半胱氨酸的加入导致钛铁试剂-铜配合物在350nm处的荧光显著增强，并且在一定浓度范围内体系荧光强度的增大与半胱氨酸浓度呈良好的线性相关性。据此建立了一种测定半胱氨酸的新方法，检测限为7．46×10^-8mol／L，线性范围为7．46×10^-7～2．20×10^-5mol／L。该方法用于测定合成氨基酸样品中的半胱氨酸，回收率为94．0％～100．7％。

The interaction between Tiron - Cu （Ⅱ） and L - Cysteine （Cys） was investigated via fluorescence and absorption spectroscopies. In pH 8.0 Britton -Robinson buffer, a significant fluorescence enhancement at 350 nm was observed upon addition of Cys into Tiron - Cu （Ⅱ） system. A new spectrofluorimetric method for the determination of Cys has been developed with good linear calibration of Cys concentration ranging from 7.46 × 10^-7 to 2.20 × 10^-5 mol/L^-1 and the detection limit as 7.46 × 10^-8 mol/L-1. The proposed assay was easy operation,high selective and sensitive. It was applied to determine Cys in synthetic amino acid samples and the recovery was 94.0 - 100.7%.