Optimizing microwave-assisted solvent extraction (MASE) of pesticides fromsoil

Microwave-assisted solvent extraction (MASE) was investigated as an alterna tive for extraction of parathion (O,O-diethyl O-4-nitrophenyl phosphorothio ate), methyl parathion (O,O-dimethyl O-4-nitrophenyl phosphorothioate), p,p '-DDE [1,1'-dichloro-2,2-bis(4-chlorophenyl)ethane], hexachlorobenzene (HCB ), simazine (6-chloro-N-2, N-4-diethyl- 1,3,5-triazine-2,4-diamine) and par aquat dichloride (1,1'-dimethyl-4,4'-bipyridinium) from two different soils and from an earthworm-growing substrate. The matrices were fortified with C-14-radiolabeled pesticides and extracted with various solvent systems und er different microwave conditions.Recoveries of more than 80% could be obta ined depending on the used microwave conditions and solvent, except for par aquat whose recovery was generally less efficient. Thus, MASE can be succes sfully used to extract pesticides from environmental and biological samples and could be a viable alternative to conventional extraction methods. The technique uses smaller amounts of organic solvents, thereby minimizing the costs of the analysis and the disposal of waste solvent.