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After an explosion of pentaerythritol tetranitrate (PETN), its degradation products pentaerythritol trinitrate (PETriN), dinitrate (PEDiN) and mononitrate (PEMN) were detected using liquid chromatography-atmospheric-pressure chemical-ionization-mass spectrometry (LC-APCI-MS). Discrimination between post-explosion and naturally degraded PETN could be achieved based on the relative amounts of the degradation products. This information can be used as evidence when investigating a possible relationship between a suspect and a post-explosion crime scene. The present work focuses on accurate quantitation of PETN and its degradation products, using PETriN, PEDiN and PEMN standards specifically synthesized for this purpose. With the use of these standards, the ionization behavior of these compounds was studied, and a quantitative method was developed. Quantitation of PETN and trace levels of its degradation products was shown to be possible with accuracy between 85.7% and 103.7% and a precision ranging from 1.3% to 11.5%. The custom-made standards resulted in a more robust and reliable method to discriminate between post-explosion and naturally-degraded PETN. © 2014 Elsevier B.V.

In this paper the insights and results are presented of a long term and ongoing improvement effort within the Netherlands Forensic Institute (NFI) to establish a valuable innovation programme. From the overall perspective of the role and use of forensic science in the criminal justice system, the concepts of Forensic Information Value Added (FIVA) and Forensic Information Value Efficiency (FIVE) are introduced. From these concepts the key factors determining the added value of forensic investigations are discussed; Evidential Value, Relevance, Quality, Speed and Cost. By unravelling the added value of forensic science and combining this with the future needs and scientific and technological developments, six forensic grand challenges are introduced: i) Molecular Photo-fitting; ii) chemical imaging, profiling and age estimation of finger marks; iii) Advancing Forensic Medicine; iv) Objective Forensic Evaluation; v) the Digital Forensic Service Centre and vi) Real time In-Situ Chemical Identification. Finally, models for forensic innovation are presented that could lead to major international breakthroughs on all these six themes within a five year time span. This could cause a step change in the added value of forensic science and would make forensic investigative methods even more valuable than they already are today.

Pentaerythritol tetranitrate (PETN) and its degradation products are analyzed to discriminate between residues originating from PETN explosions and residues obtained under other circumstances, such as natural degradation on textile, or after handling intact PETN. The degradation products observed in post-explosion samples were identified using liquid chromatography-mass spectrometry as the less-nitrated analogues of PETN: pentaerythritol trinitrate (PETriN), pentaerythritol dinitrate (PEDiN) and pentaerythritol mononitrate (PEMN). Significant levels of these degradation products were observed in post-explosion samples, whereas only very low levels were detected in a variety of intact PETN samples and naturally degraded PETN. No significant degradation was observed after 12 weeks of storage at room temperature and the influence of high relative humidity (90%) was found to be small. Natural degradation was accelerated by storage of small amounts of PETN on different types of textile, resembling the clothing of a suspect, at elevated temperature (333 K). This resulted in significant levels of PETN degradation products, but the relative amounts remained much lower than in post-explosion PETN. For PETriN the peak area relative to PETN was 0.014 (SD = 0.0051) and 0.39 (SD = 0.19) respectively. Based on the peak areas of PETriN, PEDiN and PEMN relative to PETN, it was possible to fully distinguish the post-explosion profiles from the profiles obtained from intact PETN or after (accelerated) natural degradation. Although more data are required to accurately assess the strength of the evidence, this work illustrates that PETN profiling may yield valuable evidence when investigating a possible link between a suspect and post-explosion PETN found on a crime scene. Due to the substantial variation in the degradation pattern between explosion experiments and even between sampling positions in one experiment, the method is not able to distinguish different PETN explosion events. (C) 2013 Elsevier Ireland Ltd. All rights reserved.

Background: Previously, a quantitative risk assessment suggested there was no risk of induction of fragrance allergy from minor residues of fragrance chemicals on washed fabrics. Objective: To investigate whether there was any risk of the elicitation of contact allergy from fragrance chemical residues on fabric in individuals who were already sensitized. Methods: Thirty-six subjects with a positive patch test to isoeugenol (n = 19) or hydroxyisohexyl 3-cyclohexene carboxaldehyde (n = 17) were recruited. Dose-response and fabric patch tests were performed, respectively, with filter paper and a cotton sample loaded with fragrance in ethanol-diethylphthalate (DEP) and applied in a Finn Chamber (R) or a Hill Top Chamber (R). Results: Only two subjects reacted to an isoeugenol patch test concentration of 0.01% (>20x the estimated likely skin exposure level), none reacted to lower concentrations. Of 36 subjects, 18 reacted to the fabric patch treated with ethanol-DEP vehicle alone and 20 to the fragrance-chemical-treated fabric patch. These were only minor non-specific skin reactions. They were also quite evenly distributed between the two fragrance chemical allergic groups. Conclusions: On the basis of the examples studied, fragrance chemical residues present on fabric do not appear to present a risk of the elicitation of immediate or delayed allergic skin reactions on individuals already sensitized.

Theoretical and experimental aspects of indirect UV detection are considered. Based on a mathematical treatment of the transport of ions through the capillary, resulting in an eigenvector-eigenvalue problem, some guidelines are formulated about how to increase efficiency and sensitivity in an indirect (UV) detection system. Also, the existence of system peaks can be explained properly. An experimental system consisting of seven amino acids as sample ions and salicylate at pH 11.0 as the UV-absorbing ion was chosen in order to compare theoretical and experimental results. Constructed electropherograms, produced with a computer program based on the above-mentioned mathematical treatment, are also presented and compared with experimental electropherograms.

The prevalence of contact allergy to fragrance ingredients increased during the last part of the 20th century with the consequence that a substantial number of individuals are at risk of experiencing allergic contact dermatitis (ACD) if they have a sufficient degree of skin exposure to the chemical to which they have become sensitized. Such exposure does not necessarily have to arise from the type of source that originally induced the sensitization. A number of sources of exposure are clearly associated with risk of elicitation of ACD, but the role of fragrance deposited on fabrics, for example as a result of laundry processes, also can be questioned. In this article, firstly, the risk of the induction of fragrance-related ACD from exposure to fragrance via fabric is considered. Using a quantitative risk-assessment approach, the risk appears to be extremely low. The possibility that fragrance residues on laundered fabrics might elicit reactions in those already sensitized by a different route is also discussed. Clinically, clothing pattern dermatitis associated with fragrance allergy is almost never observed, although this could be investigated clinically by exposing sensitized individuals to the relevant fragrance allergen.