硝基磺酚C-Cu(Ⅱ)-蛋白质-CTMAB体系的吸收光谱及其应用

Study on Absorption Spectrum of Nitrosulfophenol C-Cu(Ⅱ)-Proteins-CTMAB System and its Application

红色的硝基磺酚C在pH2.52的Britton-Robinson缓冲介质中能与Cu2+反应生成稳定的蓝色配合物,其配合物与生物大分子蛋白质形成有色复合物,λmax=676 nm,比试剂本身红移120 nm,表观摩尔吸光系数7.48×105 L/(mol.cm),蛋白质在0～100μg/mL范围内遵循比尔定律,CTMAB存在,灵敏度提高35%。方法线性范围宽,选择性高基本无干扰,操作简便,重现性好,灵敏度比直接用硝基磺酚C光度法高7.6倍。用于卵蛋白的测定,结果满意。

Red nitrosulfophenol C can react with proteins and Cu^2＋ to form complex in Britton-Robinson buffer solution at pH 2.52, which gives maximum absorption peak at 676 nm with 120 nm to red shift compared to that of nitrosulfophenol C. A molar absorptivity of 7.48×105 L/（mol·cm） and linear range of 0-100 μg/mL for protein were detemined. By adding surfactants to form quaternary, reaction system, the sensitivity increased by 35 %, and was 7.6 times that of binary reaction system. This method has been used for the detemination of the total protein in egg with satisfactory results.