槲皮素分光光度法测定牛血清白蛋白

在pH=5.2的B-R缓冲溶液中,对槲皮素与牛血清白蛋白(BSA)相互作用的吸收光谱进行了初步研究。结果表明:槲皮素在290nm处有一强的吸收峰,当加入BSA作用后该吸收峰的强度升高,峰位基本不变,且没有新的吸收峰出现。在此波长下测定其复合物的吸光度,其吸光度的增加值(ΔA)与BSA的浓度在18—220μg/mL范围内呈良好的线性关系(r=0.9991),检出限为8μg/mL。该方法具有简便、快速、选择性好、灵敏度高等特点,应用于鲜奶粉和液态纯牛奶样品中总蛋白的测定,回收率分别为89.5%,93.2%,结果与考马斯亮蓝G250法基本一致。

Determination of Bovine Serum Albumin by Spectrophotometry with Quercetin

The absorption spectroscopy of the complex of quercetin and bovine serum albumin (BSA) was studied preliminarily in the B-R buffer solution (pH = 5.2).Quercetin has a strong absorption at 290nm which becomes stronger when BSA is added, and no new peak appears.The absorbance of the complex is linearly proportional to concentration of BSA in the range from 18μg/mL to 220μg/mL, and the detection limit is 8μg/mL.The method is simple, fast, high selective and sensitivity.The proposed method was applied to the determination of the total protein in the fresh milk powder and liquid milk samples with satisfactory results.The experiment results are roughly identical with results obtained by the Coomassie brilliant blue G250.