Determination of alpha-tocopherol in the Traditional Chinese Medicinal preparation Sea buckthorn oil capsule by non-aqueous reversed phase-HPLC

A non-aqueous reversed phase HPLC was developed for determining alpha-tocopherol in Sea buckthorn oil capsule without the need for saponification. A reversed phase column (Alltima C(18), 4.6 x 250 mm, 5 microm) was used with a mobile phase of methanol-acetonitrile (95 : 5, v/v) and flow rate of 1 ml/min. The contents in capsule were extracted with n-hexane. Detection wavelength was set at 292 nm. Each analysis requires no longer than 20 min. The linearity range for alpha-tocopherol was 9.4-47.0 microg/ml. The detection limit was 0.94 microg/ml. The mean recovery was 95.82 (RSD 2.3%). This method is suitable for quantitative analysis of alpha-tocopherol in Sea buckthorn oil or its Traditional Chinese Medicinal preparation.