Application of an automated extractor/concentrator to the analysis of anticonvulsant drugs in blood serum by high-performance liquid chromatography.

An automated extractor/concentrator has been used to extract a variety of anticonvulsant drugs from blood serum in a concentration range from 0.075 to 80 microgram/ml. The volume of serum required varies from 0.1 to 2.0 ml, depending on the concentration of drug. The average absolute extraction recovery is 90% larger; recoveries relative to an internal standard are greater than 95%. The serum extracts were analyzed by high-performance liquid chromatography on a reversed-phase column with an acetonitrile and phosphate buffer mobile phase. Comparison of results with gas chromatographic and immunoassay techniques was excellent.