Abstract
An effective, accurate and reliable HPLC with UV detection method was developed and validated for quantitation of six components: baicalin, berberine hydrochloride, quercetin, kaempferol, isorhamnetin and baicalein in intestinal perfusate using rotundin as an internal standard. The chromatographic separation was performed on a WelchromβC~18~ column (250 Γ 4.6Β mm i.d. with 5.0Β Β΅m particle size) with a mobile phase consisting of acetonitrile, water, phosphoric acid and triethylamine (30:70:0.2:0.1,v/v) at a flow rate of 1.0Β mL/min and a UV detection at 270Β nm. The method had a chromatographic run time of 30Β min and excellent linear behavior over the investigated concentration ranges observed with the values of r higher than 0.99 for all the analytes. The lower limit of quantification of the analytical method was 0.09Β Β΅g/mL for berberine hydrochloride, quercetin, kaempferol and baicalein and 0.18Β Β΅g/mL for baicalin and isorhamnetin. The intraβ and interβday precisions measured at three concentration levels were all less than 10% for all analytes. The bias ranged from β6.91 to 4.33%. The validated method has been successfully applied to investigate the rat intestine absorption profiles of baicalin, berberine hydrochloride, quercetin, kaempferol, isorhamnetin and baicalein. Copyright Β© 2009 John Wiley & Sons, Ltd.