ORGANOCHLORINE PESTICIDE RESIDUE LEVEL IN COCOA PODS AND BEANS FROM SELECTED COCOA FARMS IN ONDO STATE, NIGERIA

Abstract

This research project investigated the level of organochlorine pesticides (OCPS) residues in cocoa farms from three major cocoa producing Local Government Areas including: Akure south, Ifedore, and Idanre representing Ondo Central Senatorial District, Ondo State Nigeria. Cocoa beans and cocoa pods were collected from three different farms in each Local Government Area of the Senatorial Districts. All samples were analyzed for organochlorine pesticide residues by Gas chromatography with electron capture (EC) detector. Prior to the chromatographic analysis, extraction of samples was carried out using a mixture of Ethyl Acetate (Et Ac) and sodium hydrogen carbonate (NaHCO3) solution. The sample extracts were then cleaned up by gel permeation chromatography (GPC) utilizing silica packed column, and a 1:1 mixture of cyclohexane /ethyl acetate as eluting solvent. The results reveal varied levels of organochlorine compounds which includes:- α, β and δ-BHC (Benzene Hexacloride), chlorothalonil,, Aldrin, Hepthachlor epoxide (B), Endosulfan I, Endosulfan II, Dieldrin, Endrin, P, P’ – DDD, CIS – Permethrin and Trans permethrin in pod and beans sample collected from the three sample locations, while lindane, Hepthachlor and O,P’-DDD were found below detection limit. The level of concentrations in cocoa pod and bean samples from Akure south farm sites showed that, endrin ranged from 2.43 - 0.79 mg/kg, endosulfan I ranged from 1.90 - 1.31mg/kg, endosulfan II ranged from 0.36 - 0.29 mg/kg, and δ –BHC ranged from 0.08 - 0.04 mg/kg, while in Ifedore LGA, endosulfan l and ll, δ - BHC and endrin were found with the following concentrations; 3.49 - 2.08 mg/kg, 0.96 - 0.30 mg/kg, 0.99 - 0.05 mg/kg and 2.26 - 1.34 mg/kg respectively. In Idanre farm sites, endosulfan l, δ -BHC and endrin were measured with the following concentration values; 2.39 - 1.57 mg/kg, 0.10 - 0.03 mg/kg and 1.66 - 0.33 mg/kg respectively. However, endosulfan l, ll, endrin, δ - BHC measured from the three farm sites show higher concentration values which exceed the maximum allowable limit (MAL) in cocoa food.