日立L-8800型氨基酸分析仪检测牛乳中掺加动物蛋白水解物

Detection of hydrolyzed animal proteins in milk by hitachi L-8800 high speed amino acid analyzer

目的：建立采用日立L-8800型氨基酸分析仪测定牛乳中掺加动物蛋白水解物的方法。方法：通过日立L-8800型氨基酸分析仪测得羟脯氨酸（HYP）的含量,由测得的HYP含量换算得出牛乳中掺加的动物蛋白水解物的量。采用标准色谱柱（ID 4.6 mm×60 mm）,日立2622型离子交换树脂作为固定相进行分离,柱后茚三酮衍生、440 nm波长定量检测的离子交换色谱法测定HYP含量。结果：HYP离子交换色谱显示其保留时间为5.50 min,线性范围为0.005~10.0 mmol/L,检出限为3 pmol,回收率为96.89%~103.62%,日内、日间测定的相对标准偏差均小于1.5%。结论：该法操作简便,分析时间短,内源物质干扰小,特异性好,准确度高,线性范围宽,检出限低,可为牛乳的卫生监督和质量控制提供有效的技术支持。

Objective：To establish a method to determine hydrolyzed animal proteins adulterated in milk by hitachi L-8800 high speed amino acid analyzer.Methods：The content of hydroxyproline（HYP） can be determined by hitachi L-8800 high speed amino acid analyzer,and the content of hydrolyzed animal proteins in adulterated milk was then calculated by HYP content.HYP was separated using column（ID 4.6 mm×60 mm）,the ion exchange resin #2622 and assayed with spectrophotometric detection at 440 nm using method of Ninhydrin post-column derivation.Results：The retention time was 5.50 min for HYP.The linear ranges of the method was from 0.005 to10.0 mmol/L for HYP,the detection limits was 3 pmol.The intraday variations and the interday variations was less than 1.5%.The recoveries was from 96.89% to 103.62% for HYP.Conclusion：The method is sample,fast,specific and suitable for routine measurement of milk.