Muehlethaler C.,University of Lausanne |
Massonnet G.,University of Lausanne |
Deviterne M.,University of Lausanne |
Bradley M.,Chemistry Unit |
And 12 more authors.
Forensic Science International | Year: 2013
This study represents the most extensive analysis of batch-to-batch variations in spray paint samples to date. The survey was performed as a collaborative project of the ENFSI (European Network of Forensic Science Institutes) Paint and Glass Working Group (EPG) and involved 11 laboratories. Several studies have already shown that paint samples of similar color but from different manufacturers can usually be differentiated using an appropriate analytical sequence. The discrimination of paints from the same manufacturer and color (batch-to-batch variations) is of great interest and these data are seldom found in the literature. This survey concerns the analysis of batches from different color groups (white, papaya (special shade of orange), red and black) with a wide range of analytical techniques and leads to the following conclusions. Colored batch samples are more likely to be differentiated since their pigment composition is more complex (pigment mixtures, added pigments) and therefore subject to variations. These variations may occur during the paint production but may also occur when checking the paint shade in quality control processes. For these samples, techniques aimed at color/pigment(s) characterization (optical microscopy, microspectrophotometry (MSP), Raman spectroscopy) provide better discrimination than techniques aimed at the organic (binder) or inorganic composition (fourier transform infrared spectroscopy (FTIR) or elemental analysis (SEM - scanning electron microscopy and XRF - X-ray fluorescence)). White samples contain mainly titanium dioxide as a pigment and the main differentiation is based on the binder composition (C-H stretches) detected either by FTIR or Raman. The inorganic composition (elemental analysis) also provides some discrimination. Black samples contain mainly carbon black as a pigment and are problematic with most of the spectroscopic techniques. In this case, pyrolysis-GC/MS represents the best technique to detect differences. Globally, Py-GC/MS may show a high potential of discrimination on all samples but the results are highly dependent on the specific instrumental conditions used. © 2013 Elsevier Ireland Ltd.
Boulassel B.,Service Medecine Legale |
Sadeg N.,Center Hospitalier Rene Dubos |
Roussel O.,IRCGN |
Perrin M.,IRCGN |
Belhadj-Tahar H.,Groupe Recherche et Expertise Toxicologiques
Forensic Science International | Year: 2011
We report here a fatal intoxication case involving ammonium vanadate. A 24-year-old woman was admitted to the Emergency Department for abdominal pain, nausea, vomiting, multiple daily diarrheas, hypoglycaemia (0.2g/L) and severe acute renal failure with glomerular filtration rate estimated at 21ml/min. This patient had taken an undetermined amount of ammonium vanadate 12h after ingesting. She died next morning in the context of respiratory distress despite intensive care and oxygen therapy. The autopsy revealed widespread asphyxia syndrome and erosive gastritis. Determination of vanadium concentration in blood was carried out by means of mass spectrometer (ICP-MS) using rhodium (103Rh) as the internal standard. The vanadium concentration was 6.22mg/L, corresponding to 6000 times higher than normal concentration in the general population. The latency and the brutality of clinical picture degradation seem to be in consideration of systemic poisoning by vanadium leading to inhibition of the cellular respiratory process. © 2010 Elsevier Ireland Ltd.
Frere B.,Incendies et Explosifs ECX |
Bernier G.,IRCGN |
Ducellier T.,IRCGN |
Actualite Chimique | Year: 2010
When firearms are found on a crime scene, investigators frequently sniff the canon aperture in order to identify which of them could have been used recently. This technique gives useful information but is not based on a scientific and validated methodology. In order to solve this problem the French Gendarmerie Forensic Research Institute has developed and validated an analytical method based on extraction of aromatic hydrocarbon residues by solid phase micro-extraction (SPME), followed by gas chromatography coupled with mass spectrometry (GC/MS).
Stable isotopes for forensic science and justice [Les isotopes stables au service de la justice: Du mécanisme de fractionnement isotopique à la signature chimique d'un produit : Applications en criminalistique]
Pierrini G.,IRCGN |
Actualite Chimique | Year: 2010
The relative abundance of certain stable isotope constituents of the material is a considerable information source and behaves as a memory of the origins (synthesis or biosynthesis) and transformation of the material. This "signature" then can be run in the process of inference of the origin of a common source in scientific police. In certain cases, it constitutes a legal method of identification.