Capillary zone electrophoresis with diode-array detection for analysis of local anaesthetics and opium alkaloids in urine samples.

The present study describes the simultaneous determination of four drugs, two local anaesthetics (lidocaine and bupivacaine) and two opium alkaloids (noscapine and papaverine) by capillary zone electrophoresis (CZE) with solid-phase extraction (SPE) procedure using Oasis HLB cartridges. Their recoveries ranged from 81 to 107% at the target concentrations of 2.0, 5.0 and 8.0 microgmL(-1) in spiked urine samples. Coefficients of variation of the recoveries ranged from 2.1 to 11.3% at these concentrations. The quantitation limits of the method were approximately 300 ngmL(-1) for the different compounds studied. The assay is very specific for these compounds and requires a short sample preparation procedure prior to the electrophoretic analysis.