Detection of Pb, Ba, and Sb in Blowfly Larvae of Porcine Tissue Contaminated with Gunshot Residue by ICP OES

Lead (Pb), barium (Ba), and antimony (Sb) concentrations were monitored in flies larvae (immature Chrysomya albiceps) contaminated with gunshot residue (GSR) from .40 caliber Taurus pistols during the period of 2 to 12 days after the death of a female pig in decomposition, during the winter, under the influence of rain and high relative humidity. The samples were also analyzed by the colorimetric test using sodium rhodizonate (Feigl-Suter reaction). It was possible to detect and quantify the three metals of interest by inductively coupled plasma-optical emission spectrometry (ICP OES), where the concentrations of all three elements kept practically constant during the putrefaction stage. Minimum ([Pb] = 382.26 μg L−1; [Ba] = 140.50 μg L−1; [Sb] = 39.18 μg L−1) and maximum ([Pb] = 522.66 μg L−1; [Ba] = 190.30 μg L−1; [Sb] = 56.14 μg L−1) concentrations were found during the third and fifth days after death, respectively. ICP OES presented higher sensitivity in metals determination when compared to the conventional colorimetric test, which showed negative result for the GSR extracts obtained from the immature Chrysomya albiceps.