RESUMEN
An improved method for the determination of Vitamin D2 in baby food (fortified dried milk) was established by using two steps of high-performance liquid chromatography (HPLC). The sample was directly saponified and extracted with benzene. The extracted unsaponifiable matter was firstly subjected to preparative HPLC using a Nucleosil 5C18 column (reversed-phase type) with acetonitrile-methanol (3:2) as a mobile phase. This first step was for the purpose of clean-up, and a fraction containing Vitamin D2 was collected. The separate fraction was subsequently subjected to analytic HPLC with a Zorbax SIL column (straight-phase type) with isopropanol-hexane (0.8 : 99.2) as a mobile phase. The Vitamin D2 was separated from other contaminants and determined with ultraviolet spectrograph by the peak height estimated. The recovery rate was 84%, standard deviation 12.57 and coefficient of variation 4.57%. The proposed method was rapid, accurate, and suitable for the determination of baby food.