Quantitative determination of seven chemical constituents and chemo-type differentiation of chamomiles using high-performance thin-layer chromatography

A simple and rapid high-performance thin-layer chromatographic method was developed for the separation and determination of six flavonoids (rutin, luteolin-7-O--glucoside, chamaemeloside, apigenin-7-O--glucoside, luteolin, apigenin) and one coumarin, umbelliferone from chamomile plant samples and dietary supplements. The separation was achieved on amino silica stationary phase using dichloromethane/acetonitrile/ethyl formate/glacial acetic acid/formic acid (11:2.5:3:1.25:1.25 v/v/v/v/v) as the mobile phase. The quantitation of each compound was carried out using densitometric reflection/absorption mode at their respective absorbance maxima after postchromatographic derivatization using natural products reagent (1% w/v methanolic solution of diphenylboric acid--ethylamino ester). The method was validated for specificity, limits of detection and quantification, precision (intra- and interday) and accuracy. The limits of detection and quantification were found to be in the range from 6-18 and 16-55ng/band for six flavonoids and one coumarin, respectively. The intra- and interday precision was found to be <5% RSD and recovery of all the compounds was >90%. The data acquired from high-performance thin-layer chromatography was processed by principal component analysis using XLSTAT statistical software. Application of principal component analysis and agglomerative hierarchial clustering was successfully able to differentiate two chamomiles (German and Roman) and Chrysanthemum.