Determination of Organochlorine Pesticide Residues in Dried Cocoa

Organochlorine pesticide residues in dried cocoa beans from selected towns from Ondo and Osun States, Nigeria were determined. Four towns Ondo and Idanre (Ondo State) and Ife and Ilesa (Osun State) were selected to represent cocoa producing areas in the states. Samples were extracted and cleaned-up on silica gel adsorbent. Pesticide residues were detected using Gas Chromatography – Mass Spectrometry (GC-MS). Five organochlorine pesticides were detected in the samples from Ondo state which includes alpha-HCH, beta-HCH, delta-HCH, endrin and p p’ DDT. The levels of p p’ DDT (0.108 mg/kg and 0.107 mg/kg) detected in samples from Ondo and Idanre towns were lower than the EU MRL (0.5 mg/kg), while other detected organochlorine pesticide residues from the State were higher than the EU MRL. In Osun State, alpha-HCH, lindane, dieldrin, endrin, heptachlor-epoxide, endosulfan I and p p’ DDT were organochlorine pesticide residues detected, with lindane (0.074 mg/kg), endosulfan I (0.099 mg/kg) and p p’ DDT (0.235 mg/kg) being lower than EU MRLs. Higher levels of organochlorine pesticide residues than the EU MRLs suggest that the produce were not safe for human consumption because of the tendency of the pestsides to persist for a long period of time and as well bioaccumulate within the environment. The produce can also face trade threat in international market. Measures were suggested to ameliorate this situation.