Comparison of extraction methods for the removal of volatile organic compounds (VOCs) present in sorbents used for human scent evidence collection

Sorbent materials used for the collection of human scent for investigative purposes have been shown to contain a variety of compounds reported as components of human scent. Many of the sorbents evaluated were biologically sterile, and it has been demonstrated that biologically sterile does not equate to analytically clean and the possibility exists for collected odor samples to be altered through interactions with the volatile organic compounds (VOCs) present initially on the sorbent material. The primary purpose of the study conducted was to evaluate various processes that can be applied to the sorbent materials to attain analytical cleanliness and eliminate the possibility of contamination of collected human odor samples. The chemical methods evaluated included Supercritical Fluid Extraction (SFE), Subcritical Water Extraction (SWE), traditional Soxhlet extraction, and autoclaving of sorbents. Optimization of the extraction parameters evaluated included temperature, pressure and extraction time, and the use of chemical modifiers such as methanol and water. Overall, SFE proved to be the most efficient method for producing sorbent materials free of human scent compounds.