Optimization of capillary electrophoresis for the analysis of organic acids and explosives

Abstract

Capillary electrophoresis (CE) is a relatively new technique for the separation and analysis of chemical compounds. Aromatic acids have been identified as the degradation products of plant matter. Distribution of the aromatic acids in the aquatic environment can provide basic information on the different sources of the overall dissolved organic matter. In this study, a CE method was developed for the determination of aromatic acids. A complete separation of seven aromatic acids was achieved in 12 minutes using the optimized CE method. A good linearity was observed for all analytes over a concentration range of 0.25 to 100 [M. The correlation coefficients (R2 ) of the calibration curves of seven aromatic acids were higher than 0.997. The relative standard deviations were less than 7% for all the aromatic acids tested. The CE method combined with solid-phase extraction (SPE) or solid-phase microextraction (SPME) was applied to the analysis of aromatic acids in natural water, soil and sediment samples. Explosives analysis is of major importance in both forensic and environmental applications. Micellar electrokinetic capillary chromatography (MECC) is an adaptation of CE where the addition of a charged micellar agent to the electrolyte provides a separation for neutral molecules. A MECC method was developed in this study for explosives analysis. All 17 explosives were well separated under 9 minutes using the optimized MECC method. The potential of using SPME as sample preparation method for CE was investigated. With features such as high separation efficiency, short analysis time, low reagent consumption and simplicity, this study demonstrated that CE method is promising for both environmental and forensic applications.