The Use of Plasma Ashing on Samples for Detection of Gunshot Residues with Scanning Electron Microscopy and Energy-Dispersive X-Ray Analysis (SEM/EDXA)

A method is described for the removal of organic material from the adhesive tape employed for collecting particles on the hands. It utilizes the coupled action of contamination by the electron beam of the scanning electron microscope (SEM) and oxygen plasma ashing. The cells of the epidermis are destroyed and only thin filaments are left, while particles that were previously concealed become evident. The treatment does not alter the morphology or composition of gunshot residue (GSR) or of inorganic environmental particles.