Qualitative and Quantitative Analysis of Pesticide Residues in Selected Fruits Sold in Ibadan Markets, Oyo State

The widespread use of synthetic pesticides in Nigerian agriculture raises important food safety concerns, particularly regarding residue levels in fresh produce sold in urban markets. This study investigates the presence and concentration of organochlorine and organophosphate pesticide residues in selected fruits, including tomatoes, oranges, cucumbers, and watermelon, purchased from three major markets in Ibadan, Oyo State, South West Nigeria. Sample preparation involved solvent extraction using the QuEChERS method, followed by clean-up with dispersive solid-phase extraction. Analysis was performed using gas chromatography coupled with a nitrogen-phosphorus detector for organophosphates and an electron capture detector for organochlorines. Results revealed detectable residues of chlorpyrifos, dimethoate, and DDT metabolites in a significant proportion of samples. Concentrations of chlorpyrifos in tomatoes from one market exceeded the European Union maximum residue limits, suggesting that pre-harvest intervals are not consistently observed. DDT detection is particularly concerning given its long-standing prohibition under the Stockholm Convention. Consumer risk assessment indicated that residue levels in most samples pose a low to moderate dietary risk for average adult consumers, though children may be at elevated risk due to higher relative intake. The study recommends regulatory enforcement of pesticide use standards, improved farmer education, and routine market surveillance. Keywords: pesticide residues, fruits, Ibadan, gas chromatography, food safety