Determination of 20 Organochlorine Pesticides in Soils Using Gas Chromatography-tandem Mass Spectrometry Coupled with Accelerated Solvent Extraction

A method was developed for the determination of 20 organochlorine pesticides in soils based on accelerated solvent extraction( ASE) and gas chromatography-tandem mass spectrometry( GC-MS / MS). Organochlorine pesticides were extracted with n-hexane-acetone( 1∶ 1,V / V) solution with the extraction temperature of 100℃ and the pressure of 1 500 psi. After the static extraction for 10 min of 2 circulation,the extracts was cleaned up by Carbon solid-phase extraction( SPE) column. The detection of 20 Organochlorine pesticides was carried out by GC-MS / MS in the multi-reacting monitoring( MRM) mode using external standard method. When sample amount was 5 g,the detection limit was between 0. 1 ~ 3. 0 μg / kg. When the spiked concentration was at low level( 8 μg / kg),the average recoveries were in the range of 70. 3% ~ 134% and the average standard deviations( RSDs) were less than 23%. The method possesses low background and high sensitivity. It can be applied to the routine analysis of the 20 Organochlorine pesticides in soils.