title: Analysis of gunshot residues as trace in nasal mucus by GFAAS.
abstract: When a gun is fired, the majority of gunshot residues are deposited on the shooter's hands. But these residues disappear through contact with surfaces or washing. Therefore, the maximum time frame to find GSR on a suspect's hands is 8h. The mucus, inside of a nostril, forms a surface layer where they are trapped foreign particles. In this way, mucus inside of a gunshot suspect's nostrils could act like an adhesive medium to stick on it gaseous particles from a gunshot. In this study, the presence of GSR in nasal mucus and its residence time is examined. A new procedure for the sampling of possible gunshot residue accumulated in the nasal mucus is designed. Samples are taken with cotton swabs moistened with a solution of EDTA and, after an acid digestion, are analysed by graphite furnace atomic absorption spectrometry. In addition, samples of hands are taken for comparison purposes. GSR recovery has been successful. The concentration of GSR in nasal mucus is found to be lower than on the hands, but with a longer residence time. Thus, it is possible to expand the sampling time of a suspect also, as nasal mucus cannot be contaminated by handling weapons.
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, University of Murcia, Murcia E-30100, Spain. Electronic address: marina.aliste@um.es.
authors.forename: Marina
authors.initials: M
authors.lastname: Aliste
authors.affiliation: Policía de Investigaciones de Chile (PDI), Laboratorio de Criminalística Regional La Serena, Chile.
authors.forename: Luis Guillermo
authors.initials: LG
authors.lastname: Chávez
mesh_terms: D000965:Antimony / Q000032:analysis*; D001464:Barium / Q000032:analysis*; D004492:Edetic Acid; D044709:Forensic Ballistics / Q000379:methods; D006225:Hand; D006801:Humans; D007854:Lead / Q000032:analysis*; D009093:Mucus / Q000737:chemistry*; D009297:Nasal Mucosa / Q000737:chemistry*; D012867:Skin / Q000737:chemistry; D013048:Specimen Handling; D013054:Spectrophotometry, Atomic; D014948:Wounds, Gunshot
chemical_list: D001464:Barium; D007854:Lead; D004492:Edetic Acid; D000965:Antimony
keywords: Forensic science; GFAAS; GSR; Gunshot residues; Nasal mucus