Comparison of Different Extraction Methods for Analysis of 10 Organochlorine Pesticides: Application of MAE–SPE Method in Soil from Beijing

Four commonly applied extraction techniques for organochlorine pesticides, microwave-assisted extraction (MAE), accelerated solvent extraction (ASE), quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction and ultrasonic solvent extraction, were applied on soil samples in order to evaluate their performances. The extracts were analyzed by GC-ECD and confirmed by GC-MS/MS. The MAE and QuEChERS extraction methods generally yielded higher results compared to the ultrasonication and ASE methods, while the lowest recovery (56.8 %) for o,p'-DDD was obtained using the QuEChERS method. The MAE method was further applied to six different soils from Beijing. In the soil samples only α-endosulfan and β-endosulfan were not detected. The ratios of α-HCH/γ-HCH and α-HCH/β-HCH indicated HCH residues likely originated from historical use of HCHs, and that technical HCHs were not likely being currently applied in Beijing.