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Particle Analysis for the Detection of Gunshot Residue (GSR) in Nasal Samples Using Scanning Laser Ablation and Inductively Coupled Plasma‐Mass Spectrometry (SLA‐ICPMS)
Author(s) -
Aliste Marina,
Arranz Sandra,
SánchezOrtega Alicia,
Sampedro M. Carmen,
Unceta Nora,
GómezCaballero Alberto,
Vallejo Asier,
Goicolea Maria Aranzazu,
Barrio Ramón J.
Publication year - 2020
Publication title -
journal of forensic sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.715
H-Index - 96
eISSN - 1556-4029
pISSN - 0022-1198
DOI - 10.1111/1556-4029.14278
Subject(s) - mass spectrometry , inductively coupled plasma mass spectrometry , analytical chemistry (journal) , chemistry , chromatography , analyte , shotgun , laser ablation , materials science , laser , biochemistry , physics , optics , gene
Currently, aluminum stub with carbon adhesive devices are used to collect inorganic gunshot residues (GSR) from the hands of a shooter. In an ideal shooting case, the gunshot particles do not persist for more than 2 h in the hands of the shooter, provided that the hands have not been washed. However, for forensic analysis and inference, the extended persistence of GSR would be desirable. This study investigates a novel GSR sampling and detection protocol. Sampling was performed in the nostrils using swab devices impregnated in ethylenediaminetetraacetic acid (EDTA). The GSRs persisted for longer periods in nasal mucus than on the hands, and particles were detected 6 h after shooting occurred. The analytical determination was conducted by scanning laser ablation‐inductively coupled plasma‐mass spectrometry (SLA‐ICPMS) which enable the identification of the number of particles and their elemental composition. Seventeen isotope signals corresponding to 13 C, 205 Tl and 15 analytes that are usually associated with the composition of GSR residues were monitored: 27 Al, 29 Si, 31 P, 33 S, 35 Cl, 39 K, 44 Ca, 57 Fe, 60 Ni, 63 Cu, 66 Zn, 118 Sn, 121 Sb, 137 Ba, and 208 Pb. The SLA technique enabled the reduction of the swab analysis time to 40 min. The effectiveness of this methodology was evaluated with two types of firearms: a pistol and a shotgun. The results indicated that the methodology proposed for the analysis of the nasal GSR was effective and that it can improve or complement the forensic analyses and inferences presented in a court.