Determination of trans-resveratrol in grape seed by coupling liquid extraction with micellar electrokinetic chromatography

A new method for the determination of trans-resveratrol in grape seed was developed by coupling liquid extraction (LE) and micellar electrokinetic chromatography (MEKC). LE was employed for sample preparation and MEKC for analytical separation. The solvent used for LE was ethyl acetate and the buffer for MEKC consisted of 25 mM borate containing 25 mM sodium dodecyl sulfate (SDS) and 2.5 mM sodium salt sulfated-beta-cyclodextrin at pH 9.0. The limit of detection (S/N = 3) was found to be 4.62 x 10(-7) g ml(-1). Linear regression of peak area versus concentration of resveratrol was checked with the r squared being greater than 0.99 for resveratrol at a concentration range of 9.25 x 10(-6) g ml(-1) to 4.63 x 10(-2) g ml(-1). The recoveries were over 90% for the determination of resveratrol in grape seed samples. The method developed can be an attractive alternative to the HPLC methods reported in the literature for the determination of resveratrol in grape seed with the advantages of a reduction of analysis time and operation cost. To the best of our knowledge, this is the first report on the determination of resveratrol in grape seed based on coupling LE and MEKC.