RESUMO
An isocratic high-performance liquid-chromatographic method is-described for the simultaneously determining carbamazepine and its biologically active metabolite, carbamazepine-10, 11-epoxide. Serum samples containing an internal standard (10-methoxycarba-mazepine) are extracted with dichlor-methane and 4 mol ? L-1 sodium hydroxide. The organic extract are evaporated at ambient temperature under a stream of nitrogen. The residues are reconstituted in mobile phase and injected on to a re-versed-phase C18 Column (150?4. 6mm I. D). The mobile phase consists of ace-tontrile/methanol/water (50/210/260 by vol) . The UV detector is operated at 214nm. The elution times of all com-pounds are within 7 min.The least detectable concentrations of carbamazepine and carbamazepine-10, 11-epoxide are 0. 08mg ? L-1 and 0.1mg ? L-1, respectively. The average absolute recovery for carbamazepine is 96.0% and for carbamazepine-10,11-epoxide is 97.3%. Within-run CV is 3. 3%~5.7%. and between-run CV is 4.3%~9.0%. The standard curve is linear at least within 40mg ? L-1 for carbamazepine and within 20mg ? L-1 for carbamazepine-10, 11-epoxide.