title: Laser-Induced Breakdown Spectroscopy for the Rapid Characterization of Lead-Free Gunshot Residues.
abstract: This study investigated the use of laser-induced breakdown spectroscopy (LIBS) and scanning electron microscopy energy dispersive X-ray spectroscopy (SEM-EDX) as means of characterizing gunshot residue (GSR) originating from commercially available lead-free rounds. Data from two experiments are presented in this work. One experiment focused on identifying prominent analytical markers present in lead-free GSR by LIBS while the other applied SEM-EDX to determine the degree of evidence preservation after LIBS analysis. Samples of GSR were collected via tape-lift method from the hands of volunteer shooters and instrumental analyses were conducted in triplicate. As a result, the lead-free ammunition analyzed in this work generated GSRs comprising primarily Ba, Al, Si, and/or K. Trace amounts of Ti, Fe, and S were also apparent in some compositions. Through SEM-EDX analysis, a spheroidal geometry consistent with traditional lead-containing GSR was observed. Additionally, it was determined that evidence is preserved after LIBS analysis which supports the implementation of LIBS as a rapid preliminary screening method followed by confirmatory testing via SEM-EDX on the preserved evidence.
authors.affiliation: Department of Chemistry and Biochemistry, Kennesaw State University, GA, USA.
authors.forename: Lashaundra A
authors.initials: LA
authors.lastname: Fambro
authors.affiliation: Department of Chemistry and Biochemistry, Kennesaw State University, GA, USA.
authors.forename: Deidre D
authors.initials: DD
authors.lastname: Vandenbos
authors.affiliation: Department of Chemistry and Biochemistry, Kennesaw State University, GA, USA.
authors.forename: Matthew B
authors.initials: MB
authors.lastname: Rosenberg
authors.affiliation: Department of Chemistry and Biochemistry, Kennesaw State University, GA, USA.
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Dockery
keywords: Gunshot residue; LIBS; SEM-EDX; evidence preservation; laser-induced breakdown spectroscopy; scanning electron microscopy energy dispersive X-ray spectroscopy