Evaluation and Optimization of Capillary Zone Electrophoresis for Common Drugs of Forensic Interest in Aqueous Matrix

Abstract

Capillary zone electrophoresis (CZE) is one of the primary analytical tools in forensic drug analysis. The purpose of this study was to evaluate and optimize the role of deionized water and diluted running buffer solutions as reconstitution solvents for CZE application. Eighteen common basic drug analytes of forensic interest were selected for the experiments, and the detection sensitivity and assay reproducibility were measured and analyzed. It was concluded that CZE detection sensitivity could be optimized using deionized water as the reconstitution solvent and injection condition of 10 kV/18s or 8 kV/18s. Diluted phosphate buffer solutions ranging from 1–10 mM reduced CZE detection sensitivity. CZE assay reproducibility could be improved by selecting electrokinetic injection of 10kV/18s for deionized water samples; assay variations were smaller in diluted buffer solutions. Results obtained from this systematic evaluation of aqueous samples were beneficial in directing and optimizing CZE characteristics in routine forensic specimen preparation and operation.