Modification and optimization of capillary zone electrophoresis for forensic drug analysis

Capillary zone electrophoresis (CZE) is one of the primary analytical tools in drug analysis. Its applications in forensic toxicology have been greatly expanded and advanced with the availability of highly selective and reproducible detectors and integration of sophisticated instrumentation. At the Toxicology Services Winnipeg of the Royal Canadian Mounted Police Forensic Science and Identification Services (RCMP-FS&IS), CZE is used as an analytical method for screening and quantitation of drugs of forensic interest. The principal objective of this thesis was to improve the overall detection sensitivity and assay reproducibility of CZE by optimizing instrumentation parameters and extraction procedures.;Reverse polarity was observed to increase detection sensitivity of the CZE assay. Optimizing injection voltage/application time also improved detection sensitivity and assay reproducibility of the method. For porcine blood samples, modification of the extraction method by deleting 1% concentrated HC1 methanolic solution from the extraction procedure and replacing deionized water with 0.02 mM phosphate buffer as reconstitution solvent improved both detection sensitivity and assay reproducibility of the CZE assay. Assay validation of five additional drug analytes further confirmed that the optimized extraction method generated either improved or comparable extraction recovery, limit of detection (LOD), and CZE results to those of the existing CZE assay used at the Toxicology Services.;In conclusion, overall detection sensitivity and assay reproducibility of CZE was enhanced through modifications of the extraction procedure and optimization of the injection voltage/application time procedure. These modifications could be adopted by the RCMP-FS&IS Toxicology Services.;Eighteen drug analytes were selected for the experiments. Aqueous solutions (both water and diluted buffer solutions) of the analytes were first evaluated by changing CZE injection parameters. Porcine blood spiked with the analytes was then extracted and analyzed using CZE assay. Method optimization of the biological matrix focused on blood extraction procedures.