Post-mortem distribution of mephedrone and its metabolites in body fluids and organ tissues of an intoxication case.

New psychoactive substances (NPS) are substances that continue to appear on the drug market to bypass controlled substance legislation. Mephedrone or 4-methylmethcathinone is becoming the most popular new psychoactive substance among youth as a recreational drug. The present study describes the optimization and validation of a sensitive method that combined clean up procedure and LC-MS/MS technique designed to simultaneously determine the presence of Mephedrone and its two metabolites (normephedrone as active metabolite and dyhidromephedrone) in post-mortem specimens (body fluids and organ tissues). To date, this is the first determination of Mephedrone metabolites in post-mortem specimens. The validated method was applied to a fatal Mephedrone intoxication case. The distribution of the three analytes in different post-mortem matrices was presented. The toxicological results of the studied case are discussed, along with autopsy, histopathological evidence and crime-scene information. The toxicological results presented in the study provide new data relative to mephedrone and the distribution of its metabolites in post-mortem specimens. In our opinion, the metabolite concentration database must be developed because the metabolites may be linked to toxicity. The pattern of parent drug and its metabolites can be helpful in the interpretation of fatal cases involving mephedrone, which will contribute to the currently limited knowledge about mephedrone and metabolites concentrations.

Cannabinoids Determination in Brain: A Supplemental Helpful in Postmortem Evaluation.

The scientific interest in cannabis has been documented by a wide literature, but postmortem studies and interpretations of autopsy findings are lacking or limited to few cases, few matrices analyzed or a small number of analytes. The present study describes the development and full in-house validation of a sensitive and simple method based on an optimized rapid clean-up procedure combined with a robust and highly sensitive liquid chromatography coupled with tandem mass spectrometry (LC-MS-MS) technique, designed to simultaneous determination of Δ9-tetrahydrocannabinol (THC), cannabidiol (CBD), 11-hydroxy-Δ9-tetrahydrocannabinol (11-OH-THC), 11-nor-Δ9-tetrahydrocannabinol-carboxylic acid (THC-COOH) and 11-nor-Δ9-tetrahydrocannabinol-carboxylic acid glucuronated (THC-COOH gluc.) in postmortem samples: central blood (CB), femoral blood (FB) and brain tissue (BR). The developed method was validated and applied to 24 postmortem cases involving cannabinoids. In this study, we presented a full optimization and validation of target analyses for each matrix. The procedure had proven to be reliable and accurate. This study adds new data, particularly about the cannabinoids concentrations in BR samples. Combined pattern (CB, FB, BR) can be used in the interpretation of postmortem cases, proving and strengthening the assessments made on blood data. BR matrix is a helpful supplement in the investigation of the role of cannabinoids as crucial or contributory factor in leading to death.

Forensic botany II, DNA barcode for land plants: Which markers after the international agreement?

The ambitious idea of using a short piece of DNA for large-scale species identification (DNA barcoding) is already a powerful tool for scientists and the application of this standard technique seems promising in a range of fields including forensic genetics. While DNA barcoding enjoyed a remarkable success for animal identification through cytochrome c oxidase I (COI) analysis, the attempts to identify a single barcode for plants remained a vain hope for a longtime. From the beginning, the Consortium for the Barcode of Life (CBOL) showed a lack of agreement on a core plant barcode, reflecting the diversity of viewpoints. Different research groups advocated various markers with divergent set of criteria until the recent publication by the CBOL-Plant Working Group. After a four-year effort, in 2009 the International Team concluded to agree on standard markers promoting a multilocus solution (rbcL and matK), with 70-75% of discrimination to the species level. In 2009 our group firstly proposed the broad application of DNA barcoding principles as a tool for identification of trace botanical evidence through the analysis of two chloroplast loci (trnH-psbA and trnL-trnF) in plant species belonging to local flora. Difficulties and drawbacks that were encountered included a poor coverage of species in specific databases and the lack of authenticated reference sequences for the selected markers. Successful preliminary results were obtained providing an approach to progressively identify unknown plant specimens to a given taxonomic rank, usable by any non-specialist botanist or in case of a shortage of taxonomic expertise. Now we considered mandatory to update and to compare our previous findings with the new selected plastid markers (matK+rbcL), taking into account forensic requirements. Features of all the four loci (the two previously analyzed trnH-psbA+trnL-trnF and matK+rbcL) were compared singly and in multilocus solutions to assess the most suitable combination for forensic botany. Based on obtained results, we recommend the adoption of a two-locus combination with rbcL+trnH-psbA plastid markers, which currently best satisfies forensic needs for botanical species identification.