title: High-performance liquid chromatographic determination of quercetin in human plasma and urine utilizing solid-phase extraction and ultraviolet detection.
abstract: An HPLC method for determining quercetin in human plasma and urine is presented for application to the pharmacokinetic study of rutin. Isocratic reversed-phase HPLC was employed for the quantitative analysis by using kaempferol as an internal standard. Solid-phase extraction was performed on an Oasis HLB cartridge (>95% recovery). The HPLC assay was carried out using a Luna ODS-2 column (150 x 2.1 mm I.D., 5 microm particle size). The mobile phase was acetonitrile-10 mM ammonium acetate solution containing 0.3 mM EDTA-glacial acetic acid, 29:70:1 (v/v, pH 3.9) and 26:73:1 (v/v, pH 3.9) for the determination of plasma and urinary quercetin, respectively. The flow-rate was 0.3 ml/min and the detection wavelength was set at 370 nm. Calibration of the overall analytical procedure gave a linear signal (r>0.999) over a concentration range of 4-700 ng/ml of quercetin in plasma and 20-1000 ng/ml of quercetin in urine. The lower limit of quantification was approximately 7 ng/ml of quercetin in plasma and approximately 35 ng/ml in urine. The detection limit (defined at a signal-to-noise ratio of about 3) was approximately 0.35 ng/ml in plasma and urine. A preliminary experiment to investigate the plasma concentration and urinary excretion of quercetin after oral administration of 200 mg of rutin to a healthy volunteer demonstrated that the present method was suitable for determining quercetin in human plasma and urine.
authors.affiliation: Kyorin University, School of Health Sciences, 476 Miyasita, Hachioji, 19486 Tokyo 19486, Japan. ishiikaz@kyorin-u.ac.jp
authors.forename: Kazuo
authors.initials: K
authors.lastname: Ishii
authors.forename: Takashi
authors.initials: T
authors.lastname: Furuta
authors.forename: Yasuji
authors.initials: Y
authors.lastname: Kasuya
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006801:Humans; D011794:Quercetin / Q000097:blood* / Q000652:urine*; D012680:Sensitivity and Specificity; D013056:Spectrophotometry, Ultraviolet / Q000379:methods*
chemical_list: D011794:Quercetin