Microwave-assisted solvent extraction and gas chromatography ion trap mass spectrometry procedure for the determination of persistent organochlorine pesticides (POPs) in marine sediment

Microwave-assisted solvent extraction of persistent organochlorine pesticides (POPs) in marine sediment was developed and optimized by means of two-level factorial designs. Six variables (microwave power, extraction time and temperature, amount of sample, solvent volume, and sample moisture) were considered as factors in the optimization process. The results show that the amount of sample to be extracted and solvent volume are statistically significant for the overall recovery of the studied pesticides, although compromise conditions have to be established with the object of avoiding overpressure in closed vessels. After extraction, a clean up step including the use of a silica cartridge was performed prior to chromatographic determination in order to remove interferences. The optimized procedure was compared to conventional Soxhlet extraction. The MS-MS ion preparation mode was applied to improve the sensitivity and selectivity of the chromatographic technique.