Chemical Analysis through CL-Detection Assisted by Periodate Oxidation

The progress of the research work of the author and his colleagues on the field of CL-emission generated by pyrogallol oxidation and further application for the direct determination of periodate and indirect or direct determination of other compounds through flow-injection manifold/CL-detection set up is described. The instrumentation used for these studies was a simple flow-injection manifold that provides good reproducibility, coupled to a red sensitive photomultiplier that gives sensitive CL-detection. In addition, recent reports on studies and analytical methods based on CL-emission generated by periodate oxidation by other authors are included

A new species Anthrenus bakaloudisi sp. nov. (Coleoptera, Dermestidae, Megatominae) from Macedonia, Greece and comparison with Anthrenus pfefferi Kalík, 1954, Anthrenus delicatus Kiesenwetter, 1851, and Anthrenus warchalowskii Kadej, Háva & Kalík, 2007

A new species Anthrenus bakaloudisi sp. nov. is described from Greece. Images of external and internal features are illustrated. The aedeagus of A. bakaloudisi has slim parameres so is compared with species that also have slim parameres from middle and eastern Mediterranean and just into Asia: A. pfefferi, A. delicatus, and A. warchalowskii. The new species differs internally from A. pfefferi in subtle ways, but it is easy to distinguish between the species using external colour pattern. Anthrenus delicatus differs from A. bakaloudisi internally and ways of distinguishing between the two species externally are described. Anthrenus warchalowskii is only known from Iran and differs from A. bakaloudisi internally. No information could be found on the likely true range of A. bakaloudisi, so the species is currently only known from Macedonia, Greece in the region of Thessaloniki

Near infrared hyperspectral imaging for forensic analysis of document forgery

[EN] Hyperspectral images in the near infrared range (HSI-NIR) were evaluated as a nondestructive method to detect fraud in documents. Three different types of typical forgeries were simulated by (a) obliterating text, (b) adding text and (c) approaching the crossing lines problem. The simulated samples were imaged in the range of 928 2524 nm with spectral and spatial resolutions of 6.3 nm and 10 mm, respectively. After data pre-processing, different chemometric techniques were evaluated for each type of forgery. Principal component analysis (PCA) was performed to elucidate the first two types of adulteration, (a) and (b). Moreover, Multivariate Curve Resolution Alternating Least Squares (MCR-ALS) was used in an attempt to improve the results of the type (a) obliteration and type (b) adding text problems. Finally, MCR-ALS and Partial Least Squares Discriminant Analysis (PLS-DA), employed as a variable selection tool, were used to study the type (c) forgeries, i.e. crossing lines problem. Type (a) forgeries (obliterating text) were successfully identified in 43% of the samples using both the chemometric methods (PCA and MCR-ALS). Type (b) forgeries (adding text) were successfully identified in 82% of the samples using both the methods (PCA and MCR-ALS). Finally, type (c) forgeries (crossing lines) were successfully identified in 85% of the samples. The results demonstrate the potential of HSI-NIR associated with chemometric tools to support document forgery identificationINCTAA (Processes no. : CNPq 573894/2008-6; FAPESP 2008/57808-1), NUQAAPE, FACEPE, CNPq, CAPES, Spanish Ministry of Science and Innovation MICINN (grant DPI2011-28112-C04-02).Silva, CS.; Pimentel, MF.; Honorato, RS.; Pasquini, C.; Prats Montalbán, JM.; Ferrer Riquelme, AJ. (2014). Near infrared hyperspectral imaging for forensic analysis of document forgery. Analyst. 139(20):5176-5184. https://doi.org/10.1039/C4AN00961DS517651841392

Monitoring compositional changes of the lipid fraction of fingermark residues deposited on paper during storage

Characterising the changes in fingermark composition as a function of time is of great value for improving fingermark detection capabilities by understanding the processes and circumstances under which target compounds become degraded. In this study, gas chromatography-mass spectrometry was used to monitor relative changes in the lipids from latent fingermarks over 28 days. Principal component analysis of the relative composition of 15 lipids in fingermarks showed that fingermark age was a significant contributor to the variability observed in the data, but that inter-donor variability was also significant. This was attributed principally to changes in the relative amounts of squalene, which rapidly decreased in the fingermarks. It was also observed, however, that most fingermarks exhibited relatively small changes in composition during the first seven days, followed by more rapid changes up to 28 days. Significant inter-donor variation of both initial fingermark composition and the rates and nature of loss processes was observed, which was reflected in the relative projection of samples from different donors. Finally, samples stored with no exposure to light or airflow for 28 days were projected significantly closer to the samples analysed on the day of deposition than those exposed to light, due to the reduced photodegradation rate of squalene