铁(Ⅲ)-茜素红S络合物光度法测定蛋白质

Determination of Protein with Complex of Ferric(Ⅲ)-Alizarin Red S by Spectrophotometry

在pH为3．6的Clark—Lub’s（C—L）缓冲溶液中，蛋白质与Fe（Ⅲ）-茜素红S络合物相互作用生成三元复合物，复合物的最大吸收峰波长A=567nm，考察了反应体系的各个影响因素，并对反应机理进行了初步讨论。在确定的最佳试验条件下，BSA浓度在0—200mg／L、HSA在0～125mg／L范围内符合比尔定律，对BSA和HSA的摩尔吸光系数ε567分别为1．61×10^5和1．75×10^5 L·mol^-1·cm^-1，据此建立了一种测定蛋白质的新方法，用于人血清样品中总蛋白的测定，结果与凯氏定氮法基本一致。

In Clark-Lub＇ s buffer solution of pH = 3.6, protein combines with ferric （ Ⅲ） - alizarin red S complex to form a ternary complex, which has a maximum absorption at 567 nm. The influencing factors and the spectral mechanism of the reactive system are studied. Under the optimum conditions , the liner range is 0 to 200 mg/L for BSA and 0 to 125 mg/L for HSA ,the molar absorptivity is 1.61 × 10^5 L · mol^-1·cm^-1 for bovine serum albumin（BSA） and 1.75 x 10^5 L · mol^-1 · cm^-1 for human serum albumin（HSA）. Based on this ,a new method is proposed to determine protein. After the method is applied in the determination of the total proteins in real human serum samples, the results are in good agreement with the Kjeldahl method.