An environmental forensic approach for tropical estuaries based on metal bioaccumulation in tissues of Callinectes danae.

The blue crab Callinectes danae is distributed throughout the Atlantic coast and this study aimed to evaluate a environmental forensics approach that could be applied at tropical estuarine systems where this species is distributed, based on the metal concentrations in its tissues. For this purpose, blue crab samples were collected in 9 sites (distributed in 3 areas) along the Santos Estuarine System, state of São Paulo, Brazil. The concentrations of Al, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb and Zn were determined in gills, hepatopancreas and muscle tissues. Sediment samples were collected and analyzed in these same sites. A data distribution pattern was identified during both sampling periods (August and December 2011). In order to validate this model, a new sampling campaign was performed in March 2013 at the Santos Estuarine System and also at Ilha Grande (state of Rio de Janeiro). These data were added to the previous database (composed of the August and December 2011 samples) and a discriminant analysis was applied. The results confirmed an environmental fingerprint for the Santos Estuarine System.

A new method for collection and identification of gunshot residues from the hands of shooters.

This work presents a novel collection method for gunshot residues (GSR) using a sampling procedure based on ethylenediaminetetraacetic acid (EDTA) solution as a complexing agent on moistened swabs. Detection was via a sector-field inductively coupled plasma mass spectrometry (HRICP-MS). The proposed collection and analytical method allowed detection of antimony (Sb), barium (Ba) and lead (Pb) after .38 shot tests. at detection limits of less than 1 microg L(-1) in four different areas of the hands of volunteers. This paper includes a discussion concerning hand areas near the thumb and forefinger as being more suitable for GSR collection as well as a comparison between differences observed using 2% diluted EDTA. 2% nitric acid solution, and simple deionized water as collecting solutions, proving the superior efficiency of EDTA in GSR recoveries.