Determination of quercetin in human plasma using reversed-phase high-performance liquid chromatography

• Published in: Journal of chromatography. B, Biomedical applications Biomedical applications, 1995-04, Vol.666 (1), p.149-155
• Main Authors: Liu, Bo, Anderson, David, Ferry, David R, Seymour, Len W, de Takats, Philippa G, Kerr, David J
• Format: Article
• Language: English
• Subjects: Chromatography, High Pressure Liquid - methods; Humans; Quercetin - blood; Reference Standards; Reproducibility of Results; Spectrometry, Fluorescence
• ISSN: 0378-4347; 1572-6495
• DOI: 10.1016/0378-4347(94)00549-K

A method is reported for the measurement of quercetin in human plasma using reversed-phase high-performance liquid chromatography (HPLC). Quercetin and kaempferol (as internal standard) were spiked into plasma samples and extracted using C 18 Sep-Pak Light cartridges (efficiency > 85%). Flavonoids were eluted with aqueous acetone (50% v/v, pH 3.5), dried down and redissolved in aqueous acetone (45% v/v, pH 3.5). The increased osmolarity promoted a phase separation and the water-saturated acetone layer, containing the flavonoids, was analysed by HPLC with aqueous acetone mobile phase (45% v/v acetone in 250 m M sodium dihydrogen sulphate. The mixture was adjusted to pH 3.5 with phosphoric acid and used at a flow-rate of 1.0 ml/min) and μBondapak C 18 column (150 × 3.9 mm I.D., 10 μm particle size). The detection limit (A 375 nm) for quercetin in plasma was 0.1 μg/ml (300 n M). The method also detects metabolites of quercetin, although these are not yet identified.