ABSTRACT
The intoxication of animals by pesticides is diagnosed by a set of evaluations including the detection of these substances in the animal or in environmental samples. The present study verified the sensibility of the bioassay with Drosophila melanogaster and thin-layer chromatography in the detection of the pesticides diazinon, dichlorvos, alphacypermethrin, deltamethrin, carbofuran and carbaryl. In the bioassay,Drosophila melanogaster flies were exposed to different concentrations of pesticides to determine the quantity able to cause 70% of mortality (CL70). In the analysis by TLC, solutions of pesticides were applied in thin-layer chromatography plates and treated with ortho-toluidine reagent to determine the minimum detectable quantity. The values of CL70 obtained by the bioassay were 0.6 ?g.mL-1 for diazinon, 0.14 ?g.mL-1 for dichlorvos, 1.5 ?g.mL-1 for alpha-cypermethrin, 1.0 ?g.mL-1 for deltamethrin, 5.0 ?g.mL-1 for carbofuran, and 21.000 ?g.mL-1 for carbaryl. The minimum quantities detectable by chromatography were 20.0 ?g.mL-1, 200.0 ?g.mL-1, 10.0 ?g.mL-1, 10.0 ?g.mL-1, 1.0 ?g.mL-1 and 0.4 ?g.mL-1 for diazinon, dichorvos, alpha-cipermethrin, deltamethrin, carbofuran and carbaryl, respectively. Although the sensibility of both methods in the detection of the pesticides was variable, they can be used as methods in the triage and identification of these compounds with the advantages of low cost and easy execution, thus allowing the implantation of these methods in laboratories with scarce resources.
KEY WORDS
Insecticides; pyrethroids; organophosphate; carbamates; intoxication