Monitoring of Organophosphorus Pesticide Residues in Vegetables of Agricultural Area in Venezuela

Monitoring of organophosphorus pesticide residues in vegetables of agricultural area in Venezuela was performed. Pesticide residues were analyzed using an Auto System Perkin-Elmer gas chromatograph, equipped with a Nitrogen-Phosphorus detector. The recoveries study of methamidophos, diazinon, chlorpyriphos, parathion-methyl, dimethoate, malathion and tetrachlorvinphos showed an average efficiency for the seven vegetables in range 72-110 percent. The organophosphorus pesticide metamidophos found were: tomato (62.5%), red pepper (37.5%), lettuce (37.5%), potatoes (31.3%), onion (12.5%) and green onion (6.3%). Diazinon was detected only in onion (12.5%), chorpyriphos only in tomato (12.5%), malathion in red pepper (31.3%), tetrachlorvinphos in red pepper (18.8%) and in lettuce (25%). The results also showed that the maximum residues limits (MRLs) of the metamidophos values found in the samples of potato, onion and green onion did not exceed the levels permitted.