A new method for collection and identification of gunshot residues from the hands of shooters

This work presents a novel collection method for gunshot residues (GSR) using a sampling procedure based on ethylenediaminetetraacetic acid (EDTA) solution as a complexing agent on moistened swabs. Detection was via a sector-field inductively coupled plasma mass spectrometry (HRICP-MS). The proposed collection and analytical method allowed detection of antimony (Sb), barium (Ba) and lead (Pb) after .38 shot tests. at detection limits of less than 1 microg L(-1) in four different areas of the hands of volunteers. This paper includes a discussion concerning hand areas near the thumb and forefinger as being more suitable for GSR collection as well as a comparison between differences observed using 2% diluted EDTA. 2% nitric acid solution, and simple deionized water as collecting solutions, proving the superior efficiency of EDTA in GSR recoveries.     

Piperazine-like compounds: a new group of designer drugs-of-abuse on the European market

1-Aryl-piperazine compounds are, depending on their substituents, selective for certain serotonin receptors and together with their easy availability and their so-called legal status, this group of psychoactive compounds are potential designer drugs-of-abuse. Internet in that respect is an important source of information and distribution facilities. Because this development may have consequences for the interpretation of future clinical and forensic toxicological case studies, some analytical aspects of 1-benzyl-piperazine (BZP), 1-[4-methoxyphenyl]-piperazine (pMeOPP) and 1-[3-trifluoromethylphenyl]-piperazine (TFMPP) were studied. BZP was not detected by the AxSYM FPIA technology designed to determine amphetamine-like compounds, but had showed some cross reactivity with EMIT d.a.u.. The cross reactivities at 300 and 12,000ng/ml (RS)-amphetamine equivalents were 0.4 and 1.3%, respectively. Although BZP was not identified directly by the REMEDi HS Drug Profiling System, it can be detected by this HPLC/UV scanning system. Using GC/NPD without derivatisation, BZP, pMeOPP and TFMPP can be analysed for and applying GC/MS without or with acetylation or trifluoroacetylation, these compounds can be identified unambiguously. The usefulness of GC/NPD and GC/MS in this respect was demonstrated by the quantitative and qualitative analysis of the content of a capsule with the synthetic stimulant A2, which proved to contain 86.4mg of BZP.     

Inferring ancestral origin using a single multiplex assay of ancestry-informative marker SNPs

Tests that infer the ancestral origin of a DNA sample have considerable potential in the development of forensic tools that can help to guide crime investigation. We have developed a single-tube 34-plex SNP assay for the assignment of ancestral origin by choosing ancestry-informative markers (AIMs) exhibiting highly contrasting allele frequency distributions between the three major population-groups. To predict ancestral origin from the profiles obtained, a classification algorithm was developed based on maximum likelihood. Sampling of two populations each from African, European and East Asian groups provided training sets for the algorithm and this was tested using the CEPH Human Genome Diversity Panel. We detected negligible theoretical and practical error for assignments to one of the three groups analyzed with consistently high classification probabilities, even when using reduced subsets of SNPs. This study shows that by choosing SNPs exhibiting marked allele frequency differences between population-groups a practical forensic test for assigning the most likely ancestry can be achieved from a single multiplexed assay.