Simple high-performance liquid chromatography method for alpha-tocopherol measurement in Rosmarinus officinalis leaves - New data on alpha-tocopherolcontent

A simple HPLC method for vitamin E (alpha -tocopherol) measurement in the l eaves of Rosmarinus officinalis has been developed and validated. It has en abled new data for ol-tocopherol content to be established. The leaves, rec ently harvested, were dried in a microwave oven and crushed; then, cu-tocop herol was directly extracted from portions of ground material with acetone, by probe sonication. After centrifugation the acetonic extract was analyse d by HPLC with ergocalciferol (vitamin D-2) added as internal standard and a gradient elution with a Nucleosil C-18 column at 35 degreesC. Validation parameters of the method can be considered adequate. For standards: lineari ty is r=0.999, recovery is 100 +/-2%, intra-assay precision has RSD=+/-3% a nd inter-assay precision has RSD=+/-6%. For samples: linearity is r=0.99, r ecovery: 93 +/-7%, intra-assay precision has RSD=+/-4% and inter-assay prec ision has RSD=+/-7%. (C) 2001 Elsevier Science B.V. All rights reserved.