Qualitative Analyses of Textile Damage (Cuts and Tears) Applied to Fabrics Exposed to the Decomposition of Carcasses and Associated Insect Activity in an Austral Summer.

Fatal stabbings are the leading cause of homicide in countries with restricted access to firearms, such as Australia. The analysis of damage on clothing imparted by a sharp object can assist in the characterization of the weapon. However, decomposition and carrion insects can modify the features of the damage, impeding textile damage analysis and crime reconstruction.

Condom evidence: Characterisation, discrimination and classification of pyrolysis-GC-MS profiles.

Analysis of condom evidence commonly focusses on the detection of silicone-based lubricants, such as polydimethylsiloxane (PDMS). Although various instruments are used to analyse silicone lubricants, pyrolysis-gas chromatography coupled to mass spectrometry (py-GC-MS) is one of the few instruments that presents immediate applicability to casework. However, considering that this technique detects silicone-based evidence, it is important to evaluate the discrimination potential of the method when applied to various samples.

A forensic international market survey of condom lubricants and personal hygiene products using ATR-FTIR coupled to chemometrics.

Condom residues may be encountered in forensic investigations as traces in sexual assault or rape cases. Casework studies have shown the value of distinguishing condom residues from other types of personal products used by women. However, up to now, there has been no investigation of their chemical variability within an international context.

Characterization and classification of water-based compounds in condoms and personal hygiene products using GC-MS.

Analysis of condom evidence commonly focusses on the detection of silicone-based lubricants, such as polydimethylsiloxane. However, water-based compounds such as propylene glycol or glycerin can also be used as condom lubricants and may, therefore, be detected as transferred traces. Evaluation of the variability amongst a large sample set from an international market is needed to determine what are the most likely compounds that may be detected in casework.

The effect of environmental degradation on the characterisation of automotive clear coats by infrared spectroscopy.

This paper presents a study into the chemical changes occurring within automotive clear coats as a result of environmental weathering, and their potential effect upon the characterisation of samples using infrared spectroscopy combined with chemometric modelling. Testing of three samples, collected from separate vehicles, exposed to the outside environment revealed no changes in model predictions over a 175 day period; however, incorrect predictions were observed following 435 days of exposure. Inspection of the corresponding infrared spectra revealed that these changes were likely due to the hydrolysis and photodegradation of polymer chains present in the clear coat, which were not observed in samples stored away from the outside environment over a one-year period.

Synchrotron FTIR characterisation of automotive primer surfacer paint coatings for forensic purposes.

Synchrotron FTIR microspectroscopy was used to characterise and assess the chemical diversity of electrocoat primer, primer surfacer and basecoats of automotive paint samples from 75 vehicles representing a range of international car manufacturers. Significant diversity was found in the synchrotron FTIR data from the primer surfacer coats. Classification using principal component analysis revealed 14 discrete groups, which could be associated with the country of manufacture, the specific manufacturer and manufacturing plant, the year of manufacture of the vehicle and in some instances the number of layers in the paint system.

Characterisation of chemical component migration in automotive paint by synchrotron infrared imaging.

Synchrotron infrared chemical imaging was employed to examine and assess the extent of interlayer component migration within multilayer automotive paint samples, with a particular emphasis on the cross-linking additive melamine. Two dimensional infrared chemical images revealed that melamine consistently diffuses in select paint samples from the underlying basecoat into the outermost clear coat layer. Pigments from the basecoat were also found to migrate into the adjoining layers.