Resumen
For the determination of gunshot residue (GSR) is commonly used adhesive plaster as base to apply the sodium rhodizonate colorimetric test by the police. In this context, this work aims to quantify the GSR deposited in shooter's hand through a 3D printed platform using digital image analysis and smartphone. The methodology is based on the colorimetric test by the formation of the colored Pb-rhodizonate complex, buffered with tartrate solution at pH 2.40 and the quantification is given by the analysis of its digital image in the ImageJ software, which generates histograms containing data relating to the color intensity of each sample. Analytical curves were constructed correlating the analytical signal with GSR in terms of Pb mass. The method was applied in shot tests and proved to be effective after successive cumulative additions of Pb in shooter's hand, which corresponds to 7 consecutive shots of pistol. GSR samples of shots of pistol Caliber .380 showed Pb masses of 2.42μg. Moreover, GSR samples of anti-aircraft howitzer shots showed Pb masses from 1.38μg to 1.49μg. It is expected that the use of the methodology can help in the elucidation of criminal events through a quick and low-cost method.