HPLC Determination of 6 Chemical Drugs Illicitly Added to AntiEpilepsy ReadyMade Traditional Chinese Medicines

HPLC was applied to the determination of 6 chemical drugs, i.e. phenobarbital, phenytoin, carbamazepine, clonazepam, sodium vedproate and diazepam illicitly added to antiepilepsy readymade traditional Chinese medicines. The TCM sample was extracted with methanol. Kromasil C18 chromatographic column was used as stationary phase, and mixtures of (A) mixed solution of 0.01 mol·L-1 KH2PO4 (adjusted to pH 2.5 with H3PO4) solution and CH3CN (90+10) and (B) acetonitrile with various proportions were used as mobile phase in the gradient elution. UVdetection at 210 nm was adopted in the determination. Linear relationships were kept between values of peak area and mass concentration of sodium vedproate in the range of 200-4 000 mg·L-1 and of the remainder 5 drugs in the same range of 5-100 mg·L-1. Detection limits(3S/N) found were ranged from 1 to 20 mg·L-1. On the base of blank sample, test for recovery was made by standard addition method; values of recovery found were in the range of 98.0%-103%, with RSD′s (n=6) in the range of 0.41%-1.9%.