Levels of organochlorine insecticide residues in cowpea grains and dried yam chips from markets in Ile-Ife, southwestern Nigeria: A preliminary survey

Abstract

Cowpea grains and dried yam chips obtained from two wholesale markets in Ile-Ife, Nigeria were analysed for
their organochlorine insecticides (Aldrin, Dieldrin, Heptachlor, Endrin, Chlordane and Endosulfan) content. The aim of the study was to evaluate the consumption safety status of these food items. Qualitative and  quantitative analysis of the insecticides after clean-up on silica gel adsorbent were carried out using Gas Chromatography equipped with Electron Capture Detector (GC-ECD). Organochlorine insecticide residues were detected in all the samples of cowpea and dried yam chips analysed with highest mean concentration of  Aldrin (0.580 ± 0.456 mg kg^-1 ) and Heptachlor (0.402 mg kg^-1 ± 0.073) measured in dried yam chips and cowpea
respectively. The levels of the residues detected in the cowpea grains and dried yam chips were generally  above the EU-MRLs, suggesting that the foodstuffs were not safe for human consumption as bioaccumulation of
these residues was likely to pose health risks to the consumers.

Keywords: Cowpea, Yam Chips, Organochlorine, Insecticides, Residues