二维液相色谱法测定婴幼儿配方食品中维生素A、D_(3)和4种维生素E异构体的含量

Determination of Vitamin A,D_(3) and Four Vitamin E Isomers in Infant Formula Food by Two-Dimensional Liquid Chromatography

应用在线中心切割双梯度双检测器液相色谱系统,建立二维液相色谱法同时测定婴幼儿配方食品中维生素A、D_(3)和4种维生素E异构体含量的方法。一维分析系统选择PEP柱,以甲醇-水体系作为流动相,完成VA、α-VE、β-VE、δ-VE、γ-VE的分离定量和VD_(3)的净化,经捕获柱捕集VD_(3)馏分转到二维色谱柱中;二维分析系统选择PAH柱,以甲醇-乙腈体系作为流动相,完成VD_(3)的定量分析。VA在1.0~10 mg/L、VD_(3)在0.1~0.8 mg/L、VE在2.5~50 mg/L浓度范围内相关系数均大于0.999;平均回收率为90.5%~102.4%;相对标准偏差RSD(n=6)为1.6%~4.5%,该方法对实际样品的检测结果与国标法的测定结果相对差异均小于10%,且VD_(3)的测定稳定性优于标准方法。该方法可同时快速、准确测定婴幼儿配方食品中VA、VD_(3)、VE的含量,提高样品分析效率。

A method for simultaneous determination of vitamin A,D_(3)and four vitamin E isomers in infant formula by two-dimensional liquid chromatography was established by using an online heart-cutting dualgradient dual-detector liquid chromatography system.The one-dimensional analysis system selects PEP column and uses methanol-water system as the mobile phase to complete the separation and quantification of VA,α-VE,β-VE,δ-VE,γ-VE and purification of VD_(3)and the VD_(3)fraction is captured by the trapping column and transferred to the two-dimensional chromatographic column.The two-dimensional analysis system selects the PAH column,and uses the methanol-acetonitrile system as the mobile phase to complete the quantitative analysis of VD_(3).The correlation coefficients of VA in the concentration range of 1.0~10 mg/L,VD_(3)in the range of 0.1~0.8 mg/L,and VE in the concentration range of 2.5~50 mg/L were all greater than 0.999;the average recovery rate is 90.5%~102.4%;the relative standard deviation RsD(n=6)is 1.6%~4.5%,the relative difference between the test results of the actual sample and the national standard method by this method is less than 10%,and the determination stability of VD_(3) is better than standard method.The method can simultaneously rapidly and accurately determine the contents of VA,VD and VE in infant formula food,and improve the efficiency of sample analysis.