Analysis of serum concentration of phenobarbital, phenytoin, carbamazepine and carbamazepine 10,11-epoxide by solvent-recycled liquid chromatography.

A rapid and precise low cost method for analysing phenobarbital, phenytoin, carbamazepine and carbamazepine 10,11-epoxide using liquid chromatography is described. Recycling reduced the mobile phase consumption by 75%. Recovery was 97.7-101.4% and between days CV was 1.3-1.7%. The retention times of potentially interfering substances are listed.