Determination of cimetidine in human plasma by use of coupled-flow injection, solid-phase extraction, and capillary zone electrophoresis

An on-line flow injection - solid-phase extraction-capillary zone electroph oresis (FI-SPE-CZE) method has been developed for determination of cimetidi ne in human plasma. Sodium dode-cylsulfate (SDS) was used as dynamic chemic al modifier for elimination of capillary contamination by biological macrom olecules. F1 on-line preconcentration and cleaning of the analyte by means of a C-18 microcolumn was performed automatically and CZE separation was pe rformed consecutively without interruption of the applied voltage and betwe en-run-washing of the capillary. A detection limit of 8 mug L-1 (3 x sigma) was achieved at a sample throughput of 12 h(-1). The approach was successf ully used for a pharmacokinetic study of cimetidine.