A Fast HPLC Method for Determination of Vitamin E Acetate in Dietary Supplements Using Monolithic Column

A simple and fast high-performance liquid chromatography (HPLC) method with rapid separation on monolithic column has been developed for quantitative determination of vitamin E acetate in dietary supplements. Commercial samples of dietary supplements were extracted with 100 % methanol with the help of ultrasound bath. A 20-μL sample volume of the filtered solution was directly injected into the HPLC system. Separation of ballast matrix, vitamin E acetate, and internal standard cholecalciferol was performed on the monolithic column Chromolith Performance RP-18e column (100 × 4.6 mm) with mobile phase methanol/water (98:2, v/v) at a flow rate of 2.0 mL min−1 and at temperature 30 °C. The detector was set at 290 nm. Under the optimum chromatographic conditions, standard calibration curve was measured with good linearity—correlation coefficient for vitamin E acetate (r = 0.9992; n = 6) between the peak areas and concentrations of vitamin E acetate. Accuracy of the method defined as a mean recovery was in the range 96.4–103.6 % for all dietary supplements. The intraday method precision was satisfactory and relative standard deviation of sample analysis including preparation and determination of different dietary supplements was in the range 1.1–3.6 %. The developed method has shown high sample throughput during sample preparation process and short time (3.5 min) of analysis.