School of Molecular and Life Sciences, Curtin University, GPO Box U1987, Perth, WA 6845, Australia.
School of Molecular and Life Sciences, Curtin University, GPO Box U1987, Perth, WA 6845, Australia; Curtin Institute of Functional Molecules and Interfaces, Curtin University, GPO Box U1987, Perth, WA 6845, Australia.
Forensic Sci Int. 2020 Aug;313:110338. doi: 10.1016/j.forsciint.2020.110338. Epub 2020 May 16.
Automotive window tints are commonly applied to motor vehicles to reduce transmittance of light and heat into the interior. They may hence be encountered as physical evidence in criminal investigations, or in civil matters where a tint is suspected to originate from a different source than advertised. Establishing a tint's provenance would be highly relevant in such cases. However, there are currently a lack of established guidelines for forensic tint analysis. This study used attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy with chemometrics to characterize automotive tints based on their adhesive composition. Minimal variability was observed within a single roll of tint, however substantial variability was observed between tints of different brands. Certain individual tint products were also found to possess highly distinctive spectra. Subsequent predictive models were able to associate unknown tint samples to their brand, and found to be robust to both adhesive curing and short-term environmental exposure over a five-month period. The use of ATR-FTIR spectroscopy and chemometrics thus offers a rapid and objective approach to discriminating automotive tints for forensic purposes.
汽车车窗膜通常应用于汽车上，以减少光线和热量进入车内的透射率。因此，它们可能会作为刑事调查中的物证出现，或者在涉及车窗膜颜色涉嫌与广告宣传不符的民事案件中出现。在这种情况下，确定车窗膜的来源将非常重要。然而，目前对于法医车窗膜分析还没有既定的准则。本研究使用衰减全反射傅里叶变换红外（ATR-FTIR）光谱和化学计量学，根据其胶黏剂成分对汽车车窗膜进行特征描述。在一卷车窗膜内观察到的变化很小，但不同品牌的车窗膜之间存在很大的差异。某些特定的车窗膜产品也被发现具有高度独特的光谱。随后的预测模型能够将未知的车窗膜样本与其品牌相关联，并且在五个月的时间内对胶黏剂固化和短期环境暴露具有稳健性。因此，ATR-FTIR 光谱和化学计量学的使用为法医目的提供了一种快速、客观的方法来区分汽车车窗膜。
