Direct chiral resolution and its application to the determination of the pesticide tetramethrin in soil by high-performance liquid chromatography using polysaccharide-type chiral stationary phase.

A high-performance liquid chromatography method is presented for the enantioseparation and quantitation of tetramethrin. The separation is achieved on amylose 3,5-dimethylphenyl-carbamate CSP (Chiralpak AD-H column) using a mobile phase consisting of a mixture of n-hexane-ethanol-2-propanol (99:0.9:0.1, v/v/v). Baseline chiral separation for the four isomers of tetramethrin is obtained within 20 min. Each of the resolutions of the two pairs of enantiomers is more than 2.0. The absolute configurations of each isomer are determined. The accuracy, precision, linearity, and limits of detection and quantitation of the method are investigated. For the determination of isomers in soil, the soil sample is extracted with acetone in an ultrasonic bath. The percentage recoveries from soil are in the range of 73.5% to 87.9%.