Abstract- Kelly Pesta

The Investigation of the Presence of Organic GSR on SEM Stubs

Pesta, Kelly; Wetzel, Stephanie; Ali, Leah

Department of Chemistry and Biochemistry

Duquesne University

Various extraction methods (100% methanol; 50% acetone/50% water (v/v); 100% acetonitrile; 70% isopropanol/ 25% water (v/v); and 50% acetone/50% acetonitrile(v/v)) were tested to determine the ideal method for extraction of organic gunshot residue (GSR) from scanning electron microscope (SEM) stubs. The ideal method was based upon the percent recovery of the seven standards investigated (Akardite II Solid, Ethyl Centralite, Methyl Centralite, and Single Based Gun Surveillance, which has four components of its own which include diphenylamine(DPA), N-nitrosodiphenylamine(N-NO-DPA), 4-nitrodiphenylamine (4-NO₂-DPA), and 2-nitrodiphenylamine (2-NO₂-DPA). These standards were quantified by the Liquid Chromatography/ Mass Spectrometry (LC-MS/MS).