Análise de resíduos de disparos de armas de fogo (GSR) usando ICP OES : desenvolvimento de uma nova metodologia analítica
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Data
2014-01-01
Autores
Vanini, Gabriela
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Universidade Federal do Espírito Santo
Resumo
Violence involving firearms is a big issue in the state of Espírito Santo and the development of new methods and techniques that can help the police to elucidate homicides is extremely important to the reduction of crime. Optical emission spectrometry with inductively coupled plasma (ICP OES) stands out as a highly sensitive, versatile and cheap technique when compared to current techniques used by the police. Therefore, the objective of this work was to develop a fast, sensitive and reliable method for collection and quantification of gunshot residues (GSR) using ICP OES to determine the concentrations of lead (Pb), barium (Ba) and antimony (Sb) released by .38 caliber handgun and .380 and .40 caliber pistols. The work was divided into three chapters. In the first, it was discussed the optimization step of the ICP OES technique for GSR, which evaluated the operating parameters of radio frequency power, nebulizer gas flow rate and aspiration rate, using multivariate central composite design. In the second chapter, a study was conducted using Taurus® .38 handgun, which investigated the best residue collection region of the hand in men and women, the feasibility of different collectors for GSR , the comparison of the colorimetric analysis and ICP OES technique for varying distances and the influence of hand washing before and after shots. The results showed that the regions of the thumb and forefinger palm, and the back of the thumb and forefinger are the best collection areas. The pure swab showed better results in terms of cost / benefit and it is possible to obtain concentrations of the metals of interest even with hand washing of shooter. In the third chapter a comparative study between .38 handgun and .380 and .40 pistols it was done. It was quantified Pb, Ba and Sb on the right and left hands of the shooters for the three weapons and held a prediction of the number of shots through the construction of a calibration curve. It was noted the amount of GRS found on the weapons, follows the order .38 handgun>.380 pistol> .40 pistol. Overall results showed important information in GSR analysis, representing a breakthrough in forensic investigations.
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Ballistic forensic , Fireams , Lead , Barium , Antimony , Balística forense , Armas de fogo , Chumbo , Bário , Antimônio
Citação
VANINI, Gabriela. Análise de resíduos de disparos de armas de fogo (GSR) usando ICP OES: desenvolvimento de uma nova metodologia analítica. 2014. 94 f. Dissertação (Mestrado em Química) - Universidade Federal do Espírito Santo, Centro de Ciências Exatas, Vitória, 2014.