乳制品中同时检测维生素K_(1)和K_(2)的方法研究

Simultaneous Determination of Vitamin K_(1)and K_(2)in Dairy Products

[目的]建立一种使用高效液相色谱-荧光检测法同时测定乳制品中维生素K_(1)和K_(2)含量的分析方法。[方法]样品经脂肪酶酶解,皂化后用正己烷萃取,锌粉还原柱柱后衍生,采用高效液相色谱-荧光检测法测定,外标法定量。[结果]维生素K_(1)和K_(2)在15 min内分离出峰。在0.01~1.60μg/mL浓度内线性范围关系良好,线性相关系数≥0.99。称取样品量5.0 g、定容体积5.0 mL时,维生素K_(1)和K_(2)检出限为2.0μg/100 g、定量限为6.0μg/100 g。添加量5~50μg/100 g时,维生素K_(1)回收率61.0%~108.5%、精密度(RSD)1.1%~9.3%,维生素K_(2)回收率75.6%~104.0%、RSD 2.0%~6.6%,RSD与回收率符合要求。[结论]试验建立方法回收率好、准确度高、重复性好,可检测乳制品中维生素K_(1)和K_(2)的含量。

[Objective]An analytical method for the simultaneous determination of vitamin K_(1)and K_(2)in dairy products by high performance liquid chromatography-fluorescence detector was established.[Method]The samples were hydrolyzed by lipase,extracted with n-hexane after saponification,derivatized by zinc powder reduction column,determined by high performance liquid chromatography-fluorescence detector and quantified by external standard method.[Result]Peaks of vitamin K_(1)and K_(2)were separated within 15 mins.The linear range was good in the concentration of 0.1~1.6μg/mL,and the correlation coefficient was≥0.99.When the sample volume was 5 g and the constant volume was 5 mL,the detection limit of vitamin K_(1)and K_(2)was 2μg/100g,and the quantitation limit was 6μg/100g.When the addition amount was 5~50μg/100g,the recovery rate of vitamin K_(1)was 61.0%to 108.5%,the precision RSD was 1.1%to 9.3%,the recovery rate of vitamin K_(2)was 75.6%to 104.0%,and the RSD was 2.0%to 6.6%,which met the requirements of precision and recovery.[Conclusion]The established method had good recovery rate,high accuracy and good repeatability,and could detect the content of vitamin K_(1)and K_(2)in dairy products.