钡A-偶氮氯膦Ⅲ络合物探针分光光度法测定蛋白质

Spectrophotometric Determination of Protein by Using Barium A-Chlorophosphonazo Ⅲ Complex as Spectral Probe

在pH 1.0～ 1.5的酸性介质中 ,蛋白质与Ba 偶氮氯膦Ⅲ络合物发生作用 ,导致络合物溶液褪色 ,其最大吸收波长处吸光度的降低值与蛋白质的浓度成正比。基于此建立了以Ba 偶氮氯膦Ⅲ络合物为光谱探针 ,分光光度测定蛋白质含量的新方法。该法灵敏度高 ,选择性好。蛋白质 (以牛血清白蛋白为例 )的浓度在 0～ 4 0mg/L范围内服从比尔定律 ,表观摩尔吸光系数ε656=6 .4 7× 10 5L·mol-1·cm-1。生物体内常见物质均不产生干扰 ,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 barium-chlorophosphonazo Ⅲ (CPAⅢ) complex as a spectral probe was established. This method is based on the binding interaction of protein with barium-CPAⅢ complex in Clark-lubs buffer at pH 1.0～1.5. The binding reaction is complete within 10 min at room temperature, and causes absorbance decrease at 656 nm of the barium-CPAⅢ complex. The decrease of absorbance is proportional to the concentration of proteins. The calibration graphs for bovine serum albumin is linear up to 40 mg/L, and the apparent molar absorptivity of binding reaction at 656 nm is 6.47×10 5L·mol -·cm -1. The method has been applied for the determination of total amounts of proteins in the human serum samples with satisfactory results.