Chiral analysis of methylphenidate and dextromoramide by capillary electrophoresis

Capillary electrophoretic methods have been developed to separate the enant iomers of methylphenidate (MPH) and dextromoramide. For MPH separation was achieved with heptakis (2,6-di-O-methyl)-beta -cyclodextrin (DMCD) as chira l selector in a 100 mM phosphoric acid buffer adjusted to pH 3.0 with triet hanolamine. Commercial samples Of D,L-erytho-MPH HCl and D,L-threo-MPH HCl were analysed using the method. There was no evidence of the presence of D, L-threo-MPH HCl in D,L-etytho-MPH HCl and vice versa. The ratio of the enan tiomers was determined for each diasteroisomer. Hydroxypropyl-beta -cyclode xtrin was the chiral selector of choice for the chiral separation of the en antiomers of moramide. The separation which gave a resolution of about 3.5 was achieved in 4 min using only a 6 cm of length of capillary. In a sample of dextro-R-moramide tartrate only a small quantity (4.9% w/w) of levo-S-m oramide was detected with this method. (C) 2001 Elsevier Science B.V. All r ights reserved.