柱前衍生液相色谱荧光检测法测定婴幼儿配方乳粉中的低聚半乳糖

Determination of galactooligosaccharides in infant formula by pre-column derivatization high performance liquid chromatography fluorescence method

目的建立一种柱前衍生高效液相色谱荧光检测法测定婴幼儿配方乳粉中的低聚半乳糖含量的分析方法。方法样品用2-氨基苯甲酰胺衍生后,经色谱柱分离,用高效液相色谱-荧光检测器检测,外标峰加和分段法定量。结果建立的方法可以测定婴幼儿配方乳粉中的低聚半乳糖含量。采用麦芽糖、麦芽三糖、麦芽四糖、麦芽五糖、麦芽六糖和麦芽七糖建立标准曲线,在1~250μg/mL线性范围内相关系数(r^2)大于0.999。回收率为85.9%~103.5%,相对标准偏差(relative standard deviation, RSD)小于5%,检出限为1.0 g/kg,定量限为3.0 g/kg。结论本方法方法重现性好,精密度高,解决了婴幼儿配方乳粉中高含量乳糖对低聚半乳糖测定的干扰问题,可以为食品中低聚半乳糖的定量提供良好的解决方案。

Objective To establish a method for the determination of galactooligosaccharides in infant formula by pre-column derivatization high performance liquid chromatography fluorescence method. Methods The samples were derived with 2-aminophenylformamide, separated by chromatographic columns, detected by high performance liquid chromatography-fluorescence detector, and quantified by external peak addition and subsection method. Results The content of galactooligosaccharides in infant formula was determined by the established method. Standard curves were established using maltose, malt trisaccharide, malt tetrasaccharide, malt pentacarose, malt hexose and malt heptacarose. They had good linear relationships in the range of 1-250 μg/mL, and the correlation coefficients (r 2 ) were above 0.999. The recoveries were 85.9%-103.5%, with the relative standard deviations of less than 5%. The limits of detection were 1.0 g/kg, and the limits of quantitation were 3.0 g/kg. Conclusion This method has good reproducibility and high precision, and solves the interference problem of high lactose content in infant formula milk powder to the determination of galactooligosaccharides, which can provide a good solution for the quantitative determination of galactooligosaccharides in food.