Simultaneous determination of baicalin, baicalein, wogonin, berberine, palmatine and jatrorrhizine in rat plasma by liquid chromatography-tandem mass spectrometry and application in pharmacokinetic studies after oral administration of traditional Chinese medicinal preparations containing scutellaria-coptis herb couple

A sensitive, rapid and selective liquid chromatography-tandem mass spectrometry (LC-MS-MS) method was developed and validated for the simultaneous determination of baicalin. baicalein, wogonin, berberine, palmatine and jatrorrhizine in scutellaria-coptis herb couple in rat plasma After protein precipitation with acetonitrile and 0 1% NaH2PO4, chromatography was performed using a C-18 column, with gradient elution with 0.1% formic acid and acetonitrile at 0 25 ml/min. All analytes including internal standards were monitored under positive ionization conditions by selected reaction monitoring with an electrospray ionization source The lower limit of quantification was 10 ng/ml for baicalin, baicalein and wogonin. and 0 6 ng/ml for berberine, palmatine and jatrorrhizine The validated method was applied in pharmacokinetic studies after oral administration of Yiqing Capsule and Gegen-Qinlian Tablet to rats (c) 2010 Elsevier B.V All rights reserved.