Determination of fluvalinate residues in beeswax by gas chromatography with electron-capture detection

A simple, rapid, and accurate method is described for the determination of residual fluvalinate in beeswax. The procedure consists of partitioning on a disposable column of diatomaceous earth (Extrelut(R)), followed by chroma tographic cleanup on a Florisil cartridge. The final extract is analyzed by capillary gas chromatography with electron-capture detection (GC-ECD). Bri efly, wax samples were dissolved in n-hexane, and the solutions were sonica ted and transferred to Extrelut columns. The fluvalinate was extracted with acetonitrile, and a portion of the extract was cleaned up on a Florisil ca rtridge, The fluvalinate was eluted with diethyl ether-n-hexane (1 + 1)and directly determined by GC-ECD, Recoveries from wax samples spiked at 5 fort ification levels (100-1500 mu g/kg) ranged from 77.4 to 87.3%, with coeffic ients of variation of 5.12-8.31%. The overall recovery of the method was 81 .4 +/- 3.2%, and the limit of determination was 100 mu g/kg.