对乙酰基偶氮羧-铈(Ⅲ)-人血清白蛋白体系的吸收光谱性质及其分析应用

Absorption Spectrometric Study on the Reaction System of Ce(Ⅲ) and HSA and Its Analytical Application

在pH 2.0~3.0的B-R缓冲介质中,对乙酰基偶氮羧(p-ACA)与铈(Ⅲ)生成蓝色配合物,其吸收峰在727nm处,而显色剂本身吸收峰在577nm处,对比度达150mm。在此显色体系中加入人血清白蛋白(HSA)时,发生消光反应,呈现在波长727nm处吸光度的减弱。试验表明:HSA的质量浓度在10~120mg·L-1范围内与相应的吸光度减弱程度(ΔA)之间呈线性关系。显色体系对HSA的表观摩尔吸光率为5.14×105L·mol-1·cm-1。加入TX-100使该体系的灵敏度提高45%。应用上述方法测定了3份人血清样品中HSA的含量,测定值与考马斯亮蓝法的测定结果一致。

In a B-R buffer medium of pH 2.0-3.0,a blue colored coordination complex was formed by the reaction of p-acetyl-carboxyazo(p-ACA)with Ce(Ⅲ),having values of absorption maxima of the complex and the reagent p-ACA at wavelengths of 727 nm and 577 nm respectively.Upon additon of definite amount of human serum albumin(HSA)to the reaction system,color-fading was observed,leading to derease in absorbance as measured at727 nm.It was found that linear relationship was kept between the magnitude of decrease in absorbance(ΔA)and mass concentration of HSA in the range of 10-120mg·L-1.Apparent molar absorptivity of the reaction system in respect to HSA found was 5.14×105 L·mol-1·cm-1.TX-100 solution was added to raise the sensitivity of the reaction system 45% higher.The above procedure was applied to the analysis of 3human serum samples,giving values of HSA in consistency with the results obtained by the method of CBB G250.