Simultaneous analysis of Vitamins A and E in infant milk-based formulae by normal-phase high-performance liquid chromatography-diode array detection using a short narrow-bore column

A rapid, simple and reproducible normal-phase (NP) high-performance liquid chromatography (HPLC)-diode array detection (DAD) method for simultaneous qualitative and quantitative determination of Vitamin A (retinol acetate and retinol palmitate) and Vitamin E (alpha-tocopherol acetate, alpha-, gamma- and delta-tocopherols) in milk-based infant formulae was developed and validated. The preparation sample was based on protein precipitation and vitamin extraction with ethanol, followed by re-extraction with hexane, while the chromatographic method was based on the use of a short narrow-bore column (50 mm x 2.1 mm; 3 microm particle size), which afforded less solvent consumption and higher mass sensitivity. The method showed acceptable values for precision, recovery and sensitivity, and proved very simple for routine analysis work.