[Analytical method for methoprene in foods using HPLC].

We studied the determination of methoprene in foods by high-performance liquid chromatography (HPLC). The sample was extracted with acetonitrile and the extract was salted out by adding sodium chloride, allowing the acetonitrile layer to separate. The acetonitrile solution was washed with hexane saturated with acetonitrile, cleaned up on a Florisil column and determined by HPLC. The recovery of methoprene from spiked samples was 74.6-82.8%. In an evaluation of this method by 6 analytical laboratories, mean recoveries from spiked samples ranged from 79.4% to 84.6%. Repeatability relative standard deviation values were 2.3-8.8% and reproducibility relative standard deviation values were 8.8-23.6%. The detection limits were 0.001-0.02 microg/g and below the detection limit of the Notified Analytical Method.