Determination of Pesticide Residues in Selected Cereals Crops Sold in Some Markets in Gbako Local Government, Niger State

Abstract

This study was conducted to determine the residues of Organophosphorus in composite samples of maize, millet, guinea corn and rice from selected markets in Gbako, Niger State, Nigeria. Modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) method was used for the extraction of the pesticide residues from the samples. The pesticide residues; chlorpyrifos and profenofos were determined by gas chromatography-mass spectroscopy (GC-MS) using GC-MS model SHIMADZU, GC 17A). The selected pesticides were extracted from the cereal grain samples using acetonitrile, anhydrous magnesium sulphate, and sodium chloride. Cleanup of the extracts was done with activated charcoal. The concentrations of 0.038 and 0.019 mg/kg were obtained for chlorpyrifos in maize and millet, respectively. The recorded values of the pesticide residues were compared with Codex maximum residue levels and were found to be below the maximum residue limits (MRLs) indicating that the values may not pose any health risk to the consumers at the moment. Although, the consumption of these foodstuffs containing these chemicals, chlorpyrifos, for a long period of time as well as their use on these crops for a long time could pose some health and environmental challenges since they are not biodegradable and their bioaccumulation could ensue. Hence, their use is suggested to be discouraged in favour of their alternatives.