高效液相色谱法测定乳粉中维生素K_1的改进

Improvement research on the determination of Vitamin K_1 in milk using High Performance Liquid Chromatography

建立了固相萃取-高效液相色谱法分析乳品中维生素K1的方法。样品经磷酸盐缓冲液和脂肪酶酶解,正己烷提取和三氧化二铝柱纯化后,以正己烷定容,以Eclipse XDB C8色谱柱（配柱后锌粉衍生柱）分析,溶解了10 mmol氯化锌、5 mmol乙酸钠和5 mmol冰醋酸的甲醇为流动相,在0.8 mL/min的流速下,激发波长243 nm,发射波长：430 nm检测。维生素K1的加标回收率为86.4%-92.6%,变异系数为1.3%-2.4%,线性范围为0.05-10.0μg/mL,相关系数为0.9994,方法的检出限为10μg/kg。该方法线性范围广,灵敏度高,净化效果好,可满足实际样品分析的需求。

An analytical method was developed for the determination of Vitamin K1 in milk by solid phase extraction-high performance liquid chromatography. The sample was enzymatic hydrolysis by lipase in phosphate buffer solution, extracted with hexane, and then the extract was purified with aluminium oxide column, and finally, Vitamin K1 was stored in hexane solution. The separation was achieved by using Eclipse XDB C8 column and an elution with the mobile phases of methanol dissolving 10 mmol Zinc chloride, 5 mmol sodium acetate and 5 mmol glacial acetic acid. The identification and quantitative analysis were carried out with fluorescence detector at excitation 243nm and emission 430 nm with flow rate 0.8 mL/min. The recoveries ranged from 86.4% to 92.6% with the relative standard deviations（RSDs）between 1.3% and 2.4%. The linear range was 0.05-10.0 μg/mL and the correlation coefficient（r^2）was 0.9994. The limit of detection was 10 μg/kg. The method is enough for the analysis of Vitamin K, in actual samples with wide linear range and high sensitivity.