High-performance liquid chromatography method to measure α- and γ-tocopherol in leaves, flowers and fresh beans from Moringa oleifera

A high-performance liquid chromatography method for the microscale determination of α- and γ-tocopherol in leaves, flowers and fresh beans from Moringa oleifera is reported. The method includes microscale saponification and extraction with n-hexane. Optimized conditions for reversed-phase HPLC with UV detection were as follows: column, 25 cm × 0.46 cm, Exil ODS 5-μm; column temperature, 25 °C; mobile phase, a 20:80 (v/v) mixture of methanol:acetonitrile; flow rate, 1.0 ml/min. With these conditions, method precision (relative standard deviation) was 5.6% for α-tocopherol and 4.9% for γ-tocopherol. We used this method to measure α- and γ-tocopherol in samples from M. oleifera as part of nutritional studies in edible plants cultivated in the Northwest México.