在线固相萃取/二维液相色谱法同时测定婴幼儿配方奶粉中多种脂溶性维生素

Simultaneous determination of fat-soluble vitamins in infant formula by online solid phase extraction with two-dimensional liquid chromatography

利用在线固相萃取技术结合二维液相色谱仪,建立婴幼儿配方奶粉中维生素A、D、E、K 1同时测定的方法。将奶粉样品皂化后,利用PLRP-S聚合物为填料的在线固相萃取柱净化强碱性皂化液,以五氟苯基柱为一维色谱柱,在紫外检测器上分离维生素A、E,以多环芳烃柱为二维色谱柱,在二极管阵列检测器上分离维生素D 2、D 3和K 1,建立在线固相萃取/二维液相色谱分析方法。对该方法进行方法验证,并与现行食品安全国家标准进行结果对比。维生素A、D、E、K 1在标准曲线浓度范围内线性良好,维生素A、维生素D 2、维生素D 3、α-维生素E、β-维生素E、δ-维生素E、γ-维生素E和维生素K 1检出限分别为4.0、1.0、1.0、40.0、40.0、40.0、40.0、4.0μg/100g,定量限分别为10、2.5、2.5、100.0、100.0、100.0、100.0、10.0μg/100g,加标回收率为91.23%~107.2%,相对标准偏差为0.67%~8.06%。该方法操作简单,重复性好,准确度高,能够满足婴幼儿配方奶粉中多种脂溶性维生素的同时检测。

An analytical method to monitor fat-soluble vitamins A,D,E,and K 1 in infant formula powder had been established which comprised online solid phase extraction(SPE)technique and two-dimensional liquid chromatography.The samples were saponified and purified by SPE column with PLRP-S polymer packing.vitamin A and vitamin E were separated by an ultraviolet detector using a pentafluorophenyl silica gel column as the one-dimensional chromatographic column.vitamin D 2,D 3,and vitamin K 1 were segregated by a diode-array detector when the polycyclic aromatic hydrocarbons column was used as the two-dimensional column.Method validation was carried out and the feasibility of the method was compared with the national food safety standard method.Results showed that all the vitamins exhibited a good linear relationship in the range of the standard curve.The limit of detection(LODs)for vitamin A,vitamin D 2,vitamin D 3,α-vitamin E,β-vitamin E,δ-vitamin E,γ-vitamin E,and vitamin K 1 were 4.0,1.0,1.0,40.0,40.0,40.0,40.0,4.0μg/100g,respectively.The limit of quantitation(LOQs)was 10.0μg/100g for vitamin A and vitamin K 1,2.5μg/100g for vitamin D 2 and vitamin D 3,100.0μg/100g forα-vitamin E,β-vitamin E,δ-vitamin E,andγ-vitamin E.The recoveries were in the range of 91.23%-107.2%and the relative standard deviation(RSD)ranged from 0.67%to 8.06%.The method is simple,has high sensitivity and good reproducibility,and can be employed perfectly to simultaneously analyze eight fat-soluble vitamins in the infant formula.