Application of micro-column HPLC to the determination of phenobarbital andcarbamazepine in human blood serum

The paper presents a method for the determination of phenobarbital and carb amazepine in human serum for routine application in therapy. Serum clean-up consists of the extraction of lipids with hexane, and the precipitation of proteins with lithium perchlorate - acetic acid acetonitrile. The supernat ant is subjected to HPLC on a micro-bore column with a C18 adsorbent with m ulti-wavelength detection at 210, 220, 230 and 240 nm. Gradient elution is performed with aqueous 0.2 M lithium perchlorate as solvent A and acetonitr ile as solvent B. Compared to other methods, the solvent consumption is 10 times less. Multi-wavelength detection increases the reliability of peak id entification. The respective detection limits for phenobarbital and carbama zepine are 0.1 mug and 0.05 mug per 1 mL of serum, with 50 muL of serum. Th e method makes it possible to determine other anticonvulsant preparations t hat are used to treat children and adults.