HPLC法测定乳粉及乳制品中酪蛋白磷酸肽含量

Determination of Casein Phosphopeptide in Milk and Milk Products by HPLC

采用等电点沉淀蛋白,固相萃取柱MCX净化,以乙腈-0.1%乙酸溶液为流动相,经ZORBAX SB-C18色谱柱梯度洗脱,二极管阵列检测器测定,建立高效液相色谱测定乳粉及乳制品中酪蛋白磷酸肽含量的检测方法。结果显示,在5.0~200.0μg/mL范围内,酪蛋白磷酸肽质量浓度与其峰面积之间具有良好线性关系,相对系数为0.9997;检出限为1.5 mg/kg,定量限为5.0 mg/kg;在5.0,100.0和200.0 mg/kg这3个水平的添加浓度下,回收率在86.9%~98.4%之间,相对标准偏差在1.2%~5.6%(n=6)之间。方法具有准确度高、精密度好、检出限低、操作简便等特点,可为乳粉及乳制品中酪蛋白磷酸肽含量的测定提供测定方法。

Precipitated by isoelectric point,purified by solid-phase extraction column MCX,the method for determination of casein phosphopeptide in milk and milk products was established by high performance liquid chromatography,with acetonitrile-0.1%acetic acid solution as mobile phase and gradient elution performed by ZORBAX SB-C18 column.The results showed that linear relationships of casein phosphopeptides were found in the range of 5.0-200.0μg/mL,and the correlation coefficient was 0.9997.The limits of detection and the limits of quantitation were 1.5 mg/kg and 5.0 mg/kg,respectively.The recoveries at levels of 5.0,100.0 and 200.0 mg/kg were ranged from 86.9%to 98.4%,and the relative standard deviations ranged from 1.2%to 5.6%(n=6).This method had the characteristics of high accuracy,good precision,low detection limit,and easy operation,which could provide a determination method for the determination of casein phosphopeptide in milk and milk products.