Forensic Analysis of Adhesive Tapes by GC-MS, GC-Ir-MS

Products detected from the GCMS analysis of the solvent extractable fraction of adhesive tapes included aliphatic and aromatic hydrocarbons indicative of an oil component. These provided a detailed molecular fingerprint which was further extended by measuring their discrete stable carbon isotopic value by compound specific isotope analysis. Consideration of these combined data sets including statistical scrutiny by principle component analysis (PCA) facilitated the distinction of adhesive tapes from different country of origin and different manufacturers with high resolution. Duct and gaffer tapes contained aliphatic products such as n-alkanes and terpenoid biomarkers which were targeted by the OilMOD concept developed by organic geochemistry researchers involved in petroleum exploration activities and successfully used to fingerprint more than 4000 oils worldwide. Electrical tapes were generally lacking in the aliphatic products used in the OilMOD assessment, but did contain aromatic hydrocarbons indicative of the aromatic fraction of oils. PCA of the C0-C2 alkylnaphthalene abundances of oils has previously proved sufficient to distinguish oil origin whilst demonstrating an analytical capability to correlate flammables suspected of use in arson incidents. Here this same approach was used to differentiate electrical tapes of different type.

Personnel

K. Grice, P.F. Greenwood, N. Aziz. J. Watling

Funding

Centre of Excellence in Mass Spectrometry

Collaborators

University of Western Australia