Assessment of the stable isotope ratio variability of cling films purchased in Australia

• Published in: Forensic chemistry 2023-05, Vol.33, p.100486, Article 100486
• Main Authors: Meikle, Joe, Jones, Kylie, Cresswell, Sarah L., Matheson, Carney, Carter, James F.
• Format: Article
• Language: English
• Subjects: Cling film; Forensic science; FTIR; Isotope Ratio Mass Spectrometry; Polymers
• ISSN: 2468-1709; 2468-1709
• DOI: 10.1016/j.forc.2023.100486

[Display omitted] •74 cling films were analysed for carbon and hydrogen isotope ratio compositions.•Discrimination of isotope ratio values were calculated using measurement uncertainty.•The discriminatory power of isotope ratios were compared to FTIR analysis.•Isotope ratio provides a discriminating power of 95% using carbon and hydrogen. The forensic comparative analysis of cling films often lacks the capability to discriminate samples to the level required for court purposes. Isotope ratio mass spectrometry (IRMS) can be used in addition to the traditional forensic analysis to add further discrimination to soft polymers such as cling films. Seventy one cling films purchased from around Australia and three sent from overseas were used to determine the variability of isotopic compositions in polyethylene cling films from Australia and to create a background database, useful for identifying the strength of comparisons. These were all analysed using Fourier Transform Infrared (FTIR) and IRMS and the results showed that FTIR analysis could discriminate 73% whilst IRMS can discriminate 95% of cling films. This study demonstrates how IRMS can be applied to the differentiation and sourcing of cling films if associated with a crime in Australia.