Novel LIBS Method for Micro-Spatial Chemical Analysis of Inorganic Gunshot Residues

• NCJ Number: 254474
• Author(s): Korina Menking-Hoggart, Luis Arroyo, James Curran, Tatiana Trejos
• Date Published: January 2019
• Length: 13 pages
• Agencies: NIJ-Sponsored
• Award: Characterization of Modern Ammunition and Background Profiles: A Novel Approach and Probabilistic Interpretation of Inorganic Gunshot Residue; Fast Screening of Firearm Discharge Residues by Laser-based Spectrochemical Methods, Electrochemical Sensors, and Chemometrics

Annotation

This study developed a reliable laser induced breakdown spectroscopy (LIBS) screening approach capable of detecting GSR in just a few minutes with minimal damage to the sample, high specificity, and sensitivity.

Abstract

Moreover, a novel micro sampling method was developed to gather three dimensional data of the simultaneous occurrence of IGSR markers from a discrete space. The method is capable of micro spatial chemical analysis from just two laser shots fired at an area of 100 mm diameter. The performance of the micro spot method is compared with our previously published bulk line method.Superior accuracy, spatial information of IGSR distribution in the sample, and a less invasive sampling are some of the advantages of the newly proposed method. Machine learning algorithms were used for the classification of samples derived from shooters' hands versus nonshooters hands, based on their LIBS spectrochemical data. (publisher abstract modified)