Inorganic Analysis in Environmental Samples by Capillary Electrophoresis

Abstract

AbstractCapillary electrophoresis (CE) is a very useful technique which involves the separation of charged species (molecules) on the basis of their movement under the influence of an applied electric field in a capillary format. CE has been developed into rapid, highly effective techniques with extremely high separation power (105–107theoretical plates) and high mass sensitivity (femtomole to zeptomole amounts of substances in nanoliter to picoliter sample volumes) with high potential for separation in the analysis of environmental sample. CE has been compared with ion chromatography (IC) in the inorganic analysis of environmental samples since inorganic ions are usually separated by IC with suppressed conductivity detection. The advantages of CE compared to IC are speed, resolution, and the lack of a need for gradient elution. Operating costs are considerably lower, since ion‐exchange columns are usually expensive. In application, however, limitations imposed by the lack of detection sensitivity complicate the technique's use and impede its wide acceptance. However, as instrumental development continues (especially in detection mode and other techniques for manipulating sensitivity), this limitation will most likely be overcome and a diversity of inorganic species in real samples has already been proved to be amenable to the analysis by CE, and more can be expected in the years ahead.In this article, to understand how CE can be applied to separation and detection of inorganic ions of environmental sample, the basic principles underlying this technique and the operating parameters of CE for inorganic analysis of environmental samples are presented. For trace analysis of environmental samples, methods for manipulating the sensitivity and selectivity control for metal ions are discussed. Techniques such as the coupling of CE with inductively coupled plasma mass spectrometry (ICPMS) are also discussed. Specific applications in real world samples which have complex matrices as well as artificial samples or reference materials are offered to demonstrate the potential of CE in the analysis of environmental pollutants.