Investigating Odor Signatures of Electronic Storage Devices

Prior research by the CT State Police, Emergency Services Unit - K9 Division, in collaboration with a CT state forensic chemist, used direct thermal analysis gas chromatography-mass spectrometry (GC-MS) to analyze various mass storage devices (MSDs). Triphenylphosphine oxide (TPPO), a flame retardant which coats all electronic printed circuit boards to prevent their overheating, was identified as a target odor training aid for dogs, being used to successfully uncover many hidden MSDs. Dogs are initially trained on TPPO, but it must be recognized that this is only the first stage of training since MSD odor profiles are complex. As training continues, real MSDs are used so dogs can recognize each device's full odor profile. In 2017, room temperature headspace analysis via solid phase microextraction (SPME) with GC-MS of electronic devices found several volatile compounds common to SIM and SD cards, and USB drives. The authors concluded that MSDs do have characteristic odor profiles, making detection with minimal false alerts feasible for trained dogs. However, no TPPO was detected or identified in this study, contradicting the previous research by the CT State Police, though this is viable due to TPPO's low room temperature volatility. This current research aims to resolve said question through an investigation of different GC-MS sampling methods of MSDs. In part 1 of this study, different GC-MS sampling methods were investigated to evaluate their capabilities and limitations in detecting and identifying TPPO, including room and high temperature headspace SPME with different fiber phases, direct heated headspace analysis, and direct thermal analysis. In part 2, various MSDs (e.g., RAM drives, SIM cards, USB flash drives) were analyzed using optimized methods from Part 1 to investigate their odor signatures. Results of this research demonstrate that MSDs do have characteristic odor profiles, however the specific profile detected depends on the method of sampling.