Pesticides and lipids occurrence in Tangier agricultural soil (northern Morocco)

This study evaluates pesticide occurrence in Tangier agricultural soil (northern Morocco). Soil samples were measured for alpha endosulfan, beta endosulfan, endosulfan sulfate, alpha HCH, beta HCH, gamma HCH, aldrin, dieldrin, endrin, o,p′ DDT, p,p′ DDD, p,p′ DDE and p,p′ DDT. The analyses were performed by gas chromatography coupled with mass spectrometry (GC/MS). Endosulfan isomers (alpha and beta) and endosulfan sulfate were detected in soil samples, in which the beta isomer showed the highest concentrations. Some DDT metabolites (o,p′ DDT and p,p′ DDE) and alpha HCH were also detected in the analyzed soil. The lipid fraction of the soil samples was extracted by accelerated solvent extraction and fractionated using chromatographic techniques. The principal biomarkers obtained were alcohols, esters, ketones, aldehydes, fatty acids and hydrocarbons. Lipid biomarkers were characterized to determine soil organic matter sources. Experimental results showed that the organic matter was mainly of plant origin, although the bacterial contribution was significant.