高效液相色谱法测定调制乳粉中维生素K2的含量

Determination of Vitamin K_(2) Content in Formulated Milk Powder by High Performance Liquid Chromatography

建立一种快速的高效液相色谱法用于分析检测调制乳粉中维生素K2的含量。取调制乳粉样品,加入脂肪酶充分酶解,以一定比例的无水乙醇/正丁醇(10:10,V:V)提取,异丙醇充分稀释,定容,0.2μm滤膜过滤过滤。采用高效液相色谱法进行测定,色谱柱为Welch Ultimate~?AQ-C18(4.6 mm×150 mm,5μm),流动相为100%甲醇,流速1.0 mL/min,进样体积20μL,柱温35℃,检测波长254 nm,以外标法定量。维生素K2在0.1~5.0μg/mL浓度范围内呈良好的线性关系,标准曲线的相关系数R2为1.000。加标回收率在103.00%~106.68%之间,精密度试验中维生素K2含量的相对标准偏差为1.7%,检出限为0.0508μg/mL。此方法操作简单、准确性好、精密度高,适用于调制乳粉中维生素K2含量测定。

A rapid high performance liquid chromatography(HPLC)method for analyzing the content of vitamin K_2 in milk powder was established.Fortified milk powder samples were enzymatically hydrolyzed with lipase,extracted with a mixture of anhydrous ethanol/normal butanol(10:10,V:V)in a certain proportion,fully diluted with isopropanol,and filtered through a 0.2μm membrane filter.Using HPLC for analysis,the chromatographic column used was the Welch Ultimate~?AQ-C_(18)(4.6 mm×150 mm,5μm),the mobile phase was 100%methanol,the flow rate was 1.0 mL/min,and the injection was 20μL,the column temperature was 35℃,and a detection wavelength of 254 nm.The standard curve of vitamin K_2 was linear in the range of 0.1–5.0μg/mL(R~2=1.000).The standard recovery was 103.00%–106.68%,the relative standard deviation(RSD)of vitamin K_2 in precision experiment was 1.7%,the limit of detection was 0.0508μg/mL.The method is simple,accurate and accurate,making it suitable for the determining the content of vitamin K_2 in milk powder.