The Analysis of Tire Rubber Traces Collected After Braking Incidents Using Pyrolysis‐Gas Chromatography/Mass Spectrometry

Abstract

Automobile tire marks can routinely be found at the scenes of crime, particularly hit-and-run accidents and are left on road surfaces because of sudden braking or the wheels spinning. The tire marks are left due to the friction between the tire rubber and the solid road surface, and do not always demonstrate the tire tread pattern. However, the tire mark will contain traces of the tire. In this study, Pyrolysis Gas Chromatography/Mass Spectrometry was used to analyze 12 tires from different manufacturer's and their traces collected after braking incidents. Tire marks were left on a conglomerate road surface with sudden braking. The samples were pyrolysed without removal of contaminant in a micro-furnace type pyrolyser. Quantitative and qualitative analysis were performed on all the samples. All 12 samples were distinguished from each other. Each of the tire traces were identified as coming from there original source.

Use of a Deuterated Internal Standard with Pyrolysis-GC/MS Dimeric Marker Analysis to Quantify Tire Tread Particles in the Environment

“…The right-handed isomer, (+)-limonene, is found in citrus fruits and used in cleaning products and cosmetics. In pyrolysis analysis of rubber traces generated in tire skidding, the dipentene (mixture of isomers) pyrolysis fragment and (+)-limonene eluted at different retention times [60] and limonene is readily biodegradable [61], thus reducing the likelihood of interference from industrial or natural sources of (+)-limonene.With respect to vinylcyclohexene used to quantify BR and SBR, the primary source in environmental samples is SBR from tire wear [25]. Vinylcyclohexene was not identified as one of the 36 most abundant fragment compounds detected in the humic acid or humin of an Italian agricultural soil [56].…”

“…The right-handed isomer, (+)-limonene, is found in citrus fruits and used in cleaning products and cosmetics. In pyrolysis analysis of rubber traces generated in tire skidding, the dipentene (mixture of isomers) pyrolysis fragment and (+)-limonene eluted at different retention times [60] and limonene is readily biodegradable [61], thus reducing the likelihood of interference from industrial or natural sources of (+)-limonene.…”

Tire Classification by Elemental Signatures Using Laser-Induced Breakdown Spectroscopy

“…Even with skid mark patterns being less visible, tire trace evidence can still be found. 4 Tire traces can be embedded in the road material even if a skid mark does not fully form, on vehicles, or even dramatically on individuals, such as their clothing. Studies have also shown that even with a nonvisible skid mark, some material is still left in the form of tire trace and could be analyzed for composition.…”

Forensic analysis of tire rubbers based on their sulfur chemical states

“…Additionally, analyzing tire rubber using Fourier-transform infrared microscopy, which is commonly used to analyze trace material, is difficult because tire rubber is nontransparent due to carbon black. Generally, the trace tire rubber is analyzed using pyrolysis-gas chromatography [1,2] or pyrolysis-gas chromatography mass spectrometry (pyro-GC/MS) [3]. Trace tire rubber, which is often found on road surfaces or clothes, is analyzed using pyro-GC/MS.…”