Development of a reverse-phase high-performance liquid chromatography method for analyzing trans-resveratrol in peanut kernels

A reverse-phase high-performance liquid chromatography (HPLC) method for identification and quantification of trans-resveratrol from peanut extracts, using phenolphthalein as internal standard, was developed. The HPLC system consisted of a C18 column (250 l × 4.6 i.d. mm, 5 μm particle size), with PDA detection at 307 nm and mobile phase consisting of 0.1% acetic acid in water and 100% acetonitrile. Gradient elution increased acetonitrile linearly from 5% to 41.8% over 23 min (GS = 1.6) followed by an increase of acetonitrile to 77% over 5 min (GS = 7.04), returning to initial conditions over 1 min and held for an additional 5 min with a flow rate of 1.5 ml/min. A lower column temperature resulted in higher peak heights and better baseline separation, therefore 25 °C was selected over 40 or 60 °C to simplify the method. Accuracy, precision, linearity, limit of detection and limit of quantitation were consistent or better than reported previously in the literature for related studies.