Chemical Fingerprinting of Adhesive Tapes by GCMS Detention of Petroleum Hydrocarbon Product

• NCJ Number: 224724
• Journal: Journal of Forensic Sciences Volume: 53 Issue: 5 Dated: September 2008 Pages: 1130-1137
• Author(s): Nurhuda Aziz B.Sc.; Paul F. Greenwood Ph.D.; Kliti Grice Ph.D.; R. John Watling Ph.D.; Wilhelm van Bronswijk Ph.D.
• Date Published: September 2008
• Length: 8 pages
• Publication Format: Article
• Publication Type: Report (Study/Research)
• Language: English
• Country: United States of America

Annotation

Since pressure-sensitive adhesive tapes are often key evidence in crimes such as assault, rape, or homicide, this study used gas chromatography-mass spectrometry (GC-MS) analysis of the solvent extractable fractions of a sample of electrical and gaffer adhesive tapes with a range of colors and manufacturers in order to identify a number of petroleum-derived hydrocarbons.

Abstract

The GC-MS analysis of the solvent extractable fractions of adhesive tapes detected low concentrations of alkylnaphthalene, hopane, and sterane hydrocarbon products. Tapes from various adhesive tape manufacturers were distinguished by small variations in the distributions of these oil-derived hydrocarbons. Linear discriminant analysis (LDA) of the relative abundances of alkylnaphthalene products provided conclusive discrimination of the tape manufacturer identity, with the LDA classification able to correlate data correctly from foreign tape samples not used in the trained model. Stable carbon isotope (delta13C) signatures of the adhesive layer of the tapes also showed a small, but measurable, difference between tapes from different manufacturers. The molecular hydrocarbon and isotopic analyses of the adhesive tapes contributes to a detailed chemical fingerprint from which different manufacturers could be distinguished. Characterizations of the tapes could be further extended by incorporation of additional petroleum hydrocarbon products or other stable isotopic values, as well as by extraction of larger sample amounts in order to measure more of the biomarkers of low concentration. This strategy will be applicable to many common materials comprising petroleum products, such as polymers, lubricants, and condoms. The study used 32 adhesive tape samples (22 electrical, 2 duct, and 8 gaffer tapes). Also described are the extraction and fractionation of tape sample, GC-MS procedures, the statistical treatment of GC-MS data, and the measurement of the bulk stable carbon isotopic composition of the adhesive. 5 tables, 4 figures, and 33 references