Revista de investigación forense

Preliminary Evaluation of the Field and Laboratory Emission Cell (FLEC) for Sampling Attribution Signatures from Building Materials

Abstract

Scott D Harvey, Lijian He and Jon H Wahl

Clandestine laboratories [e.g., drug, explosive, or chemical warfare (CW)] can be processed for chemical evidence that identifies the synthetic targets and reaction paths. Further, trace impurities contained in the product constitute a fingerprint that can correlate laboratories, associate distributed product (i.e., a terrorist CW attack) with the production laboratory, or relate various attacks. This phenomenological study evaluates the field and laboratory emission cell (FLEC) for its suitability for sampling volatile attribution signatures. Dissipation of a wide range of attribution signature representatives was studied from a variety of typical building materials using FLEC sampling. Results showed rapid and near complete analyte evaporation from metal, intermediate permanence on Teflon, and strong retention on vinyl tiles. FLEC also proved useful for sampling residues left after dissipation of a sulfur mustard stimulant. In summary, preliminary evaluation of FLEC for forensic attribution applications looks promising. Advantages, practical considerations, and disadvantages of FLEC sampling are discussed.