On-line derivatization into precolumns for the determination of drugs by liquid chromatography and column switching: determination of amphetamines in urine
A chromatographic system for the on-line derivatization of drugs using column switching is described. The system uses a 20 mm × 2.1 mm i.d. precolumn packed with a unmodified ODS stationary phase. This column is used for sample cleanup and enrichment of t