Search

A high-performance liquid chromatography method for the microscale determination of alpha- and gamma-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 x 0.46 cm, Exil ODS 5-microm; column temperature, 25 degrees 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 alpha-tocopherol and 4.9% for gamma-tocopherol. We used this method to measure alpha- and gamma-tocopherol in samples from M. oleifera as part of nutritional studies in edible plants cultivated in the Northwest México.

This study presents an HPLC method for the simultaneous quantification of retinol, alpha-tocopherol, and cholesterol in shrimp waste hydrolysate lipid fraction. The method includes microscale saponification and extraction with n-hexane. Liposoluble vitamins and cholesterol were quantified by HPLC with UV detection (HPLC-UV), on a 25 cm x 0.46 cm SS Exil ODS 5 microm column, mobile phase 68:28:4 (v/v/v) methanol:acetonitrile:water; flow rate 1.4 ml/min; column temperature 36 degrees C. The detection was operated using two channels of a diode-array spectrophotometer, 325 nm for retinol and 208 nm for alpha-tocopherol and cholesterol. With these conditions, the overall recovery was 95.7, 100.8, and 98.0% for retinol, alpha-tocopherol, and cholesterol, respectively. The method precision (relative standard deviation) was 1.83% for retinol, 2.32% for alpha-tocopherol, and 1.98% for cholesterol. This method was used to quantify the cited analytes in the hydrolysate obtained during lactic acid fermentation of shrimp waste. This hydrolysate may be a valuable supplement of nutrients in fish production.