DETERMINATION OF QUERCETIN IN HUMAN PLASMA BY HPLC WITH SPECTROPHOTOMETRIC OR ELECTROCHEMICAL DETECTION

A reversed-phase high-performance liquid chromatographic method for th e determination of quercetin in human plasma following intravenous inf usion is described. Quercetin in plasma was extracted with methanol-di methyl sulphoxide (4:1 v/v) and separated on a C-18 Hypersil-BDS colum n with 44% (v/v) methanol in 0.1 nr ammonium acetate (pH 5.15) contain ing 0.27 mM EDTA as the mobile phase. The drug was detected specifical ly and sensitively at its absorption maximum of 375 nm, or electrochem ically, with a detection limit of 80 ng/mL and 2 ng/mL, respectively. (C) 1998 John Wiley & Sons, Ltd.