高效液相色谱法测定乳制品中纳他霉素分析方法的改进

目的优化高效液相色谱法(high performance liquid chromatography,HPLC)测定乳制品中纳他霉素含量的分析方法。方法对测定纳他霉素GB/T 21915-2008《食品中纳他霉素的测定》的高效液相色谱法中样品的提取溶剂、蛋白沉淀剂、色谱流动相及流速进行优化,并对优化后的方法进行方法学验证。结果选择10%的冰乙酸水溶液作为样品提取溶剂;乙酸锌和亚铁氰化钾作为蛋白沉淀剂;甲醇-水-冰乙酸(60:40:2,V:V:V)作为流动相;流速为1.0 mL/min。可以在7 min内完成对目标物的分离,线性方程为Y=43315X-1751,r~2=0.99997,方法平均回收率在98.5%~106.3%之间,相对标准偏差(relative standard deviation,RSD)均小于2.2%,方法检出限为0.02 mg/L。结论该方法前处理简单,回收率及灵敏度高,准确度和稳定性好,适用于对纯牛奶、乳酸菌饮料、奶粉等乳制品中纳他霉素的分离和定量检测。

Optimization of the method for determination of namycin in dairy products by high performance liquid chromatography

Objective To optimize the method for determination of natamycin content in dairy products by high performance liquid chromatography (HPLC). Methods According to GB/T 21915-2008 Determination of namycin in food-High performance liquid chromatography, the extraction solvent, protein precipitant, chromatographic mobile phase and flow rate of the sample were optimized, and the optimized method was validated by methodology. Results The 10% glacial acetic acid aqueous solution was selected as extraction solvent of sample, methanol-water-acetic acid (60:40:2, V:V:V) was selected as the chromatographic mobile phase with zinc acetate and potassium ferricyanide as protein precipitants, and the flow rate was 1.0 mL/min. The separation of the target could complete within 7 min. The linear equation of natamycin was Y=43315X?1751 with r2 of 0.99997. The average recoveries were 98.5%-106.3% with the relative standard deviations less than 2.2%, and the limit of detection was 0.02 mg/L. Conclusion The proposed method is simple, accurate and precise, which is suitable for the separation and quantitative detection of natamycin content in pure milk, lactic acid bacteria beverage, powdered milk and other dairy products.