Enantiomeric analysis of pyrethroids and organophosphorus insecticides

The use of pesticides has increased sharply in the last decades, not only in agriculture, but also in industry, public health, and other areas. Pyrethroids and organophosphorus insecticides are among the most employed pesticides. These chemicals usually contain asymmetric chiral atoms; thus, they are characterized by stereoisomerism. Although most of these chiral pesticides are produced, used, and released as racemic mixtures, the different enantiomers of these compounds can present different insecticidal activity, different toxicity against vertebrates and invertebrates, and also different persistence in the environment. In fact, in some cases, only one enantiomer is active, while the other can be less active or even toxic to non-target organisms. Therefore, the development of enantioselective analytical methodologies enabling their determination presents a high interest. Different separation techniques, including high performance liquid chromatography, gas chromatography, supercritical fluid chromatography, and capillary electrophoresis, have been employed to achieve the chiral analysis of pyrethroids and organophosphorus insecticides. This review presents the characteristics of the stereoselective analytical methodologies developed with this aim from 2010 to April 2019 and their applications to the analysis of real samples as well as for toxicity and biodegradation studies.