Evaluation of Cryofocusing Capillary Microextraction of Volatiles for Improved Detection of Organic Gunshot Residue on the Hands of Shooters Thesis

thesis or dissertation chair

fiu authors

  • Mulloor, Jerome


  • The capillary microextraction of volatiles (CMV) device was equipped with a novel Peltier cooler to investigate cryofocused extraction of organic gunshot residue (OGSR) for the first time. Prior research demonstrated the CMV’s capabilities for detecting nitroglycerin, 2,4-dinitrotoluene, diphenylamine, and ethyl centralite on shooters’ hands via gas chromatography-mass spectrometry. Further method development increased the recoveries of these four target compounds with an optimal 20-minute equilibrium time at 80˚C followed by extracting 3 L at a 1 L/min flow rate. The Cryo-CMV was evaluated for detection of semi-volatile OGSR compounds. The unique challenges presented with sampling of semi-volatiles were overcome by sample heating, applying high (>1 L/min) sampling flow rates and heating the transfer line between the container and cooled CMV. Cryofocusing at -10˚C provided increased recoveries for smokeless powders and OGSR compounds and therefore demonstrates excellent potential for other forensic applications with analysis of VOCs from fire debris and illicit drugs.

publication date

  • March 24, 2017


  • GC-MS
  • capillary microextraction of volatiles (CMV)
  • cryofocusing
  • gunshot residue
  • headspace extraction

Digital Object Identifier (DOI)