High-performance liquid chromatograph coupled with two detectors: A UV spectrometer and a polarimeter : Example in the field of pyrethroids: Identification of enantiomers

Abstract

Identification of enantiomers is possible by using two detectors in high-performance liquid chromatography: a UV spectrometer and a polarimeter. In a mixture of enantiomers and diastereoisomers, such as those resulting from a chemical structure with several asymmetric carbons, the UV spectrometer allows the detection of the diastereoisomers, whereas the polarimeter permits the identification of the enantiomers.Deltamethrin, an optically pure synthetic pyrethroid widely used as an agricultural insecticide, can undergo partial isomerization, especially through the action of light. Every photoisomer in the resulting mixture is a diastereoisomer of deltamethrin with two possible enantiomeric forms. The above method was applied to determine the spatial configurations of the isomers formed, and conclusions were drawn about the mechanism of photoisomerization.