Assessment of Organophosphorus and Pyrethroid Pesticide Residues in Lactuca sativa L. and Solanum macrocarpum L. cultivated in Benin

Pesticides are harmful and toxic in nature. They are used for vegetable protection against pest attack. The present study aimed to determine the level of Organophosphorus and Pyrethroid residues in vegetables (Solanum macrocarpum L. and Lactuca sativa L.). Thirty one vegetable samples (16 samples of Solanum macrocarpum L. and 15 samples of Lactuca sativa L.) from four vegetable farms were collected. The samples were cleaned up before the extraction was performed. Analysis was then processed using the QuEChERS method. Residue analysis was performed using a GC-PFPD for Organophosphorus residues and GC-ECD for Pyrethroid residues. MedCalc Statistical Software version 15.0. was used for the statistical analysis. The results revealed that most of the samples are contaminated by Pyrethroid and Organophosphorus residues. Among Pyrethroid residues detected, 6.5% of cypermethrin and 43.75% of lambda cyhalothrin levels in Solanum macrocarpum L. have exceeded the maximum residue limits while in Lactuca sativa L. 40% of lambda cyhalothrin and 20% of fenvalerate levels exceeded also the maximum residue limits. For Organophosphorus analyzed, 6.25% of diazinon, 12.5% of chlorfenvinp, 18.75% of fenitrothion, 25% of dimethoate and pirimiphos methyl, 50% of profenofos, 56.25% of malathion and 75% of chlorpyrifos levels in Solanum macrocarpum L. exceeded maximum residue limits while 13.33 % of ethoprofos and chlorfenvinp, 20% of profenofos and fenitrothion, 26.67 % of methamidophos, dimethoate and pirimiphos-methyl, 46.67% of malathion and 53.33% of chlorpyrifos levels in Lactuca sativa L. were exceeded the maximum residue limits. No significant difference was observed between the level of Pyrethroid and Organophosphorus residues which are above maximum residue limits in Solanum macrocarpum L. and Lactuca sativa L. The levels of Pyrethroid and Organophosphorus detected in vegetable samples show that the sanitary qualitary of these vegetables is affected