钇(Ⅲ)-偶氮胂Ⅲ配合物探针分光光度法测定蛋白质的研究

Study on the Spectrophotometric Determination of Proteins by Using Yttrium(Ⅲ)-ArsenazoⅢ Complex as Spectral Probe

在pH2．3～2．5的B-R缓冲介质中，蛋白质与钇（Ⅲ）偶氮胂Ⅲ配合物发生结合反应，引起配合物溶液褪色及吸光度降低。在一定范围内其最大吸光度降低值与蛋白质的浓度成正比。基于此，建立了以钇（Ⅲ）-偶氮胂Ⅲ配合物为光谱探针，分光光度测定蛋白质含量的新方法。该法灵敏度高，线性关系好，人血清白蛋白的含量在0～20mg／L范围内与配合物吸光度的降低值呈现良好的线性关系；表观摩尔吸光系数ε652为2．60×10^6L·mol^-1·cm^-1；生物体内的常见物质基本上不干扰测定。本法可直接应用于人血清样品中蛋白质总量的测定。

A new method for the determination of proteins by using Yttrium（ Ⅲ ）-Arsenazo Ⅲ complex as a spectral probe has been established. This method is based on the binding interaction of protein with Yttrium （Ⅲ）-Arsenazo Ⅲ complex in Briton-Robinson buffer at pH 2. 3～2. 5. The binding reaction is complete within 30 min at room temperature, and causes absorbance decrease at 652 nm of the Yttrium （Ⅲ）-Arsenazo Ⅲ complex. The decrease of absorbanee is proportional to the concentration of proteins. The calibration curve for human serum albumin is linear up to 20 mg/L, and the apparent molar absorptivity of binding reaction at 652 nm is 2.6〉（ 10^6 L·mol^-1 ·cm^-1. The method has been applied to the determination of total amounts of proteins in the human serum samples with satisfactory results.