Chiral Analysis of Pesticides and Emerging Contaminants by Capillary Electrophoresis—Application to Toxicity Evaluation

Chiral analysis is a very relevant topic in environmental chemistry. This is due to the different properties of the stereoisomers of chiral compounds. In the case of agrochemicals, the desired activity, degradation rate, or toxicity, among other characteristics, may differ between stereoisomers, and the same is true for emerging contaminants, such as pharmaceuticals and cosmetics. Therefore, the development of chiral analytical methodologies enabling their determination in samples of environmental interest is paramount. Although other techniques have been widely employed to carry out chiral separations, such as HPLC, GC, and SFC, capillary electrophoresis (CE) has attracted a lot of attention in the field of chiral analysis due to its simplicity, flexibility, and low cost. In fact, chromatographic columns are not needed, and the consumption of reagents and samples is very low due to the small dimensions of the separation capillaries. This article reviews the characteristics of the chiral methodologies developed by CE for the stereoselective analysis of pesticides and emerging contaminants in environmental samples (water and soil), as well as pesticides in food samples and commercial agrochemical formulations. Applications of the developed CE methodologies in stability and toxicity studies of these chiral contaminants are also reviewed.