Determination of clofentezine in medical herb extracts by chromatographic methods combined with diode array scanning densitometry.

The aim of this study is to report a new procedure for extraction, cleanup and determination of clofentezine in herb extracts by ultrasound-assisted solvent extraction, SPE and multidimensional planar chromatography with diode array detector (MDPC-DAD) and/or HPLC-DAD. The application of various extraction solvents in SPE experiments conducted on octadecyl silane coupled with styrene-divinylbenzene cartridges for fractionation and purification samples has been described. Normal-phase systems were used in MDPC experiments on silica layer. The procedure described for the determination of compounds is inexpensive and can be applied to the routine analysis of analytes in plant extracts, after preliminary cleanup and concentration, e.g. by SPE. Application of MDPC-DAD and HPLC-DAD is especially useful for correct identification of components of difficult, complicated mixtures, e.g. analytes in medical herbs.