SEM image of a GSR particle coupled with the EDS spectrum of its elemental composition
Gateway Analytical is proud to announce the acquisition of its third scanning electron microscope which is coupled with energy dispersive spectroscopy (SEM-EDS). This latest SEM-EDS system, manufactured by ASPEX Corporation, is fully equipped with the latest Perception Suite software and will be used exclusively for the analysis of forensic gunshot residue (GSR) evidence. Gateway Analytical has again combined validated instrumentation with a documented laboratory quality system to ensure that this newest SEM-EDS system complies and exceeds the already stringent ISO and cGMP guidelines.
Currently at Gateway Analytical, SEM-EDS analysis is utilized for routine forensic testing methodologies, including manual analysis of particulate, defects, failure testing, metal analysis, paint, glass and tapes. However, a very unique capability of using automated SEM-EDS analysis is implemented for samples such as gunshot residue. Automated SEM-EDS analysis of GSR allows for multiple samples of evidence to be analyzed at a very fast rate – numerous GSR particles can be detected and differentiated from other non-GSR particles in mere hours – this is drastically faster than a forensic scientist analyzing samples one at a time.
Gunshot residue (GSR) particles are formed from the combustion of primer and gunpowder propellants. The resultant residue product, known as gunshot residue (GSR) is typically composed of three elements: lead (Pb), barium (Ba) and antimony (Sb). GSR particles are spherical and range in size from sub-micrometer to several hundred micrometers. As noted in The Scientific Working Group on Gunshot Residue (SWGGSR) Guide for Primer Gunshot Residue Analysis by Scanning Electron Microscopy/Energy Dispersive X-Ray Spectrometry, SEM-EDS is the most advantageous method for analyzing GSR as the technique is non-destructive, minimal sample preparation is necessary, individual particles can be relocated and analyzed for confirmations, and GSR can be identified on the basis of elemental composition and morphology.
For more information on GSR evidence analysis or to inquire about our new SEM-EDS system, please contact us.