Chase G W, Long A R
U.S. Food and Drug Administration, Atlanta Center for Nutrient Analysis, GA 30309, USA.
J AOAC Int. 1998 May-Jun;81(3):582-6.
A liquid chromatographic method is described for analysis of all-rac-alpha-tocopheryl acetate, tocopherols, and retinyl palmitate in milk-based infant formula. The vitamins are extracted from infant formula without saponification by matrix solid-phase dispersion and quantitated by normal-phase chromatography with fluorescence detection. Retinyl palmitate and vitamin E are quantitated isocratically with mobile phases of 0.125% (v/v) and 0.5% (v/v) isopropyl alcohol in hexane, respectively. Results were similar to the certified and non-certified ranges for all-rac-alpha-tocopheryl acetate, retinyl palmitate, and tocopherols in the infant formula standard reference material (SRM) 1846. Results also compared favorably with the label declaration on a retail infant formula. Recoveries were determined on an analyte-fortified zero control reference material for milk-based infant formula and averaged 96.8% (n = 30) for retinyl palmitate and 91.5% (n = 25) for all-rac-alpha-tocopheryl acetate. Examination of 5 concentrations for each analyte gave results that were linear (r = 0.999) over the concentration examined, with coefficients of variation ranging from 1.02 to 5.86%. The method provides a rapid, specific, and easily controlled assay for analysis of retinyl palmitate and vitamin E in fortified infant formula. Additionally, the method minimizes solvent use by using only 14 mL solvent per extraction.
本文描述了一种液相色谱法，用于分析以牛奶为基础的婴儿配方奶粉中的全消旋α-生育酚乙酸酯、生育酚和视黄醇棕榈酸酯。通过基质固相分散法从婴儿配方奶粉中提取维生素，无需皂化，然后通过正相色谱法和荧光检测进行定量分析。视黄醇棕榈酸酯和维生素E分别在含0.125%（v/v）和0.5%（v/v）异丙醇的己烷流动相中进行等度定量分析。结果与婴儿配方奶粉标准参考物质（SRM）1846中全消旋α-生育酚乙酸酯、视黄醇棕榈酸酯和生育酚的认证范围和非认证范围相似。结果与零售婴儿配方奶粉上的标签声明相比也很理想。在一种添加了分析物的基于牛奶的婴儿配方奶粉零对照参考物质上测定回收率，视黄醇棕榈酸酯的平均回收率为96.8%（n = 30），全消旋α-生育酚乙酸酯的平均回收率为91.5%（n = 25）。对每种分析物的5个浓度进行检测，结果在所检测的浓度范围内呈线性（r = 0.999），变异系数在1.02%至5.86%之间。该方法为强化婴儿配方奶粉中视黄醇棕榈酸酯和维生素E的分析提供了一种快速、特异且易于控制的测定方法。此外，该方法每次提取仅使用14 mL溶剂，最大限度地减少了溶剂的使用。
