Multi-residue Analysis of Organochlorine Pesticides inCocoa Beans (Theobroma cacao) and Soils from Ondo,Nigeria

Organochlorine pesticides (OCPs) residues were determined in a total of 160 samples comprisingof cocoa beans and soil collected from four major cocoa farms in Ondo, Nigeria. The residueswere extracted with dichloromethane, cleaned up by column chromatography and analysed withGas Chromatography-Electron Capture Detector(GC-ECD). In the analysed cocoa samples,endrin andendosulfan I had the highest incidence of occurrence of 93% and 89%,respectivelywhile lindane and heptachlor had the least occurrence of 19%. High incidences of occurrence inthe soil samples were observed in endrin (93%) and endosulfan I (94%) while the least occurrencewasα-HCH (13%). The total residual concentrations of the OCPs were higher in the cocoasamples compared to the soil samples. The mean residual levels of HCHs (α,β,δ)aldrin, dieldrin,endrin and endosulfan I and cis-permethrin in thecocoa samples were above Maximum ResidualLimits(MRL)established by WHO/FAO whilealdrin, dieldrin, endrin, endosulfans in the soilsample analysed were above MRL established by Netherlands. Bioaccumulation factor > 1 wasrecorded in most of the cocoa samples from the different farms especially for endrin, dieldrin,endosulfan I andtrans-permethrin. Thisgives cause for concern considering the adverse healthhazards pose by these pesticides.