Detección y cuantificación de propoxur en la sucesión de insectos de importancia médico-legal

Abstract

To detect and quantify the amount of Propoxur in insects of forensic importance and search for entomotoxicologic indicators, the HPLC (High Performance Liquid Chromatography) technique was used on individuals collected during the ecological succession associated with the corpses of rabbits. Three rabbits were sacrificed with an overdose of Propoxur and a fourth control rabbit was sacrificed by cervical dislocation. The rabbits were checked over 28 days, three times a day (07:00, 13:00 and 18:00 hours). During this period, immature and adult insects were collected, and the ambient temperature, corporal temperature and weight loss were measured. From the collected material, 73 individuals from among the immatures (larvae I, II, III, pupae) and adults of the order Diptera and Coleoptera were selected and the component of interest was evaluated by HPLC. There was a positive result in 56% of the samples from larva I to adult in all the successional stages of decomposition. This technique allowed a high sensitivity from 0.1 g or less for each sample in the quantification of Propoxur residues in larvae and adults. Samples with a weight of 0.0029 g for Diptera and 0.029 g for Coleoptera were quantified. The minimum detected concentration (0,671 ppm) was found in stadium II larvae of Calliphoridae and Muscidae dipterans and the maximum quantified concentration (229,721 ppm) was found in stadium III larvae of Lucilia eximia (Diptera: Calliphoridae), with percentages of 0.04 and 0.34, respectively.