Abstract: Samples of maize, millet and sorghum were collected from strategic grain reserve facilities located in eight states in Nigeria, while cowpea samples were collected from local open markets in Kano, Lagos and Akwa Ibom States of Nigeria. The samples were screened for the presence of fifteen pesticides (permethrin, bifenthrin, lamda-cyhalothrin, dicchlorvos, cypermethrin, DDT, parathion, malathion, aldrin, paraquat, diquart, chlordane, toxaphene, imidacoprid, actamiprid) using ultra high pressure liquid chromatography- coupled with mass spectrometry (UPLC-MS). The EPA Method 3540C solvent system in a Soxhlet extractor was applied for sample extraction and the method validation was satisfactory. Three pesticides were detected, viz permethrin, cypemethrin and dichlorvos and quantitative analyses of the pesticides, and their degradation products was carried out using gas chromatography coupled with electron capture detector (GC-ECD) and UPLC-MS. Spike recovery/reproducibility for GC-ECD was 90%,with LOD of 0.138ppm and LOQ of 0.46ppm. seven samples exceeded the WHO and FAO permissible levels for permethrin using GC-ECD, 14 samples exceeded the permissible levels of permethrin using UPLC-MS. 16 grain samples indicated the the presence of dichlorvos but below LOQ while 6 samples indicated the presence of cypermethrin but below LOQ. All cowpea samples had dichlorvos levels that exceeded the permissible levels by WHO and FAO (CODEX Alimentarius). Degradation products of permethrin and cypermethrin were detected in some samples. These results indicate the need for action to be taken to allow the revision of practices in the administration of pesticides during both cropping and storage of grain in Nigeria to reduce risks of pesticide poisoning.
Keywords: Pesticide residue, degradation product, Strategic grain reserve facility, Maize, millet, Sorghum, cowpea, GC-ECD, UPLC-MS.
Title: Assessment Of Levels Of Pesticide Residues And Their Degradation Products In Selected Grains From The Strategic Grain Reserve Facilities In Nigeria
Author: Senge Florence Ekanem, Abdulrahman. A. Audu, Marya Lieberman
International Journal of Interdisciplinary Research and Innovations
ISSN 2348-1218 (print), ISSN 2348-1226 (online)
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