ANALYSIS OF SULTHIAME IN SERUM BY NARROW-BORE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY - COMPARISON OF DIRECT SAMPLE INJECTION WITH PRECOLUMN SWITCHING AND EXTRELUT EXTRACTION

Two high-performance liquid chromatographic methods for the analysis of sulthiame in serum are described. In the first method direct injection of serum samples onto a 4 x 4 mm I.D. (C18, 25-mu-m) precolumn in a column-switching device was used. After a purge step, the adsorbed analytes were eluted onto a 250 x 3 mm I.D. (C18, 5-mu-m) narrow-bore column for chromatographic separation. In the second method the sample pretreatment was an Extrelut extraction with dichloromethane-propanol-2 (95:5). After evaporation of the solvents, the residue was dissolved in methanol. The chromatographic separation was carried out on the same analytical column as used in the column-switching method. Both sample pretreatment methods were compared with respect to their suitability of routine analysis of sera from patients also receiving other antiepileptic drugs.