Retrospective screening of new psychoactive substances (NPS) in post mortem samples from 2014 to 2021.

Systematic retrospective processing of previously analysed biological samples has been proven to be a valuable tool in the search for new drugs (e.g. new psychoactive substances (NPS)) and for quality assessment in clinical and forensic toxicology. In a previous study, we developed a strategy for retrospective data-analysis using a personalized library of synthetic cannabinoids, designer benzodiazepines and synthetic opioids obtained from the crowdsourced database HighResNPS (https://highresnps.com). In this study, the same strategy was employed for the compounds within the groups of NPS that were not previously included such as synthetic cathinones, phenethylamines, aminoindanes, arylalkylamines, piperazine derivates, piperidines, pyrrolidines, indolalkylamines and arylcyclohexylamines. Synthetic opioids and designer benzodiazepines, which were not part of the previous study, were also included. To enhance the effectiveness of the retrospective analysis, a predicted retention time was included for all entries. Data files from the analysis of 2186 forensic post mortem samples with an Agilent Technologies 6540 ultra-high pressure liquid chromatography quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS) performed in the laboratory from January 2014 to December 2021 were retrospectively processed with the up-to-date library. Tentative findings were classified in two groups: The findings where MS/MS data was acquired for library match (category 1) and the less certain findings where such data lacked (category 2). Five compounds of category 1 (three synthetic cathinones and two indolalkylamines) were identified in 12 samples. Only one of the findings, 4-MEAPP (4-methyl-α-ethylaminopentiophenone), was deemed plausible after reviewing case information. As many as 501 presumably positive category 2 findings were detected. Using the predicted retention time as an additional criterion the number was significantly reduced but still too high for a manual review. This work has demonstrated that the strategy developed in the previous study can be applied to other NPS groups. However, it is important to note the limitations such a method may have in detecting compounds at very low concentrations.

Preliminary Study on the Possibility to Detect Virus Nucleic Acids in Post-Mortem Blood Samples.

BACKGROUND: In many forensic cases, the medical records of the deceased are not available at the time of the autopsy; therefore, no information about the deceased's state of health, including any infectious diseases contracted during life, is accessible. The detection of some of the principal viral infections, such as hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus type 1 (HIV-1), could contribute to determining causes of death and interesting applications could be found in medico-legal practice, such as occupational risk assessment. To date, accurate and sensitive serological and molecular assays capable of detecting these viruses have been validated on biological samples taken from living beings, while their efficiency on forensic post-mortem biological samples has yet to be thoroughly assessed. To further this aim, this study evaluated whether the nucleic acid amplification techniques (NAATs) for the detection of viral genomes that are applied in clinical settings can be used, with the same success rate, for these latter samples. METHODS: Manual viral nucleic acid extraction processes and fully-automated amplification-based detection techniques developed in-house were evaluated on blood samples taken during the routine autopsies of 21 cadavers performed 2 to 9 days after death. Information on HBV, HCV, and HIV-1 seropositive status was previously known for only four of these cadavers. RESULTS: Using automated quantitative real-time PCR (qPCR) and qualitative PCR (end-point) analyses, it was possible to confirm the presence of viral genomes in the four post-mortem whole blood samples with previously reported specific serological positivity. In addition, the genomes of HCV and/or HIV-1 genomes were detected in three other blood samples with unknown serological status at the time of autopsy. CONCLUSIONS: Therefore, our findings suggest that molecular assays may detect the presence of viral genomes in forensic post-mortem blood samples up to five days after death. This provides an additional means of investigation that can contribute to the determination of the deceased's cause of death.

Retrospective screening of synthetic cannabinoids, synthetic opioids and designer benzodiazepines in data files from forensic post mortem samples analysed by UHPLC-QTOF-MS from 2014 to 2018.

The introduction of new psychoactive substances (NPS) on the illicit drug market has led to major challenges for the analytical laboratories. Keeping screening methods up to date with all relevant drugs is hard to achieve and the risk of missing important findings in biological samples is a matter of concern. Aiming for an extended retrospective data analysis, diagnostic fragment ions from synthetic cannabinoids (n=251), synthetic opioids (n=88) and designer benzodiazepines (n=26) not included in our original analytical method were obtained from the crowdsourced database HighResNPS.com and converted to a personalized library in a format compatible with the analytical instrumentation. Data files from the analysis of 1314 forensic post mortem samples with an Agilent 6540 ultra high pressure liquid chromatography quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS) performed in our laboratory from January 2014 to December 2018 were retrieved and retrospectively processed with the new personalized library. Potentially positive findings were grouped in two: The most confident findings contained MS/MS data for library match (category 1) whereas the less confident findings lacked such data (category 2). Five new category 1 findings were identified: Flubromazepam in two data files from 2015 and 2016, respectively, phenibut (4-amino-3-phenylbutyric acid) in one data file from 2015, fluorofentanyl in one data file from 2016 and cyclopropylfentanyl in one data file from 2018. Retention time matches with reference standards further strengthened these findings. A list of 35 presumably positive category 2 findings was generated. Of these, only one finding of phenibut was considered plausible after checking retention times and signal-to-noise ratios. This study shows that new compounds can be detected retrospectively in data files from QTOF-MS using an updated library containing diagnostic fragment ions. Automatic screening procedures can be useful, but a manual re-evaluation of positive findings will always be necessary.

Analysis of organophosphorus pesticides in whole blood by GC-MS-µECD with forensic purposes.

In the present work, two multi-residue methods for the determination of ten organophosphorus pesticides (OPs), namely chlorfenvinphos, chlorpyrifos, diazinon, dimethoate, fenthion, malathion, parathion, phosalone, pirimiphos-methyl and quinalphos, in post-mortem whole blood samples are presented. The adopted procedure uses GC-MS for screening and quantitation, and GC-µECD (electron capture detector) for compound confirmation. Three different Solid Phase Extraction (SPE) procedures for OPs with Oasis(®) hydrophilic lipophilic balanced (HLB) and Sep-Pak(®) C18 cartridges were tested, and followed by GC-µECD and GC-MS analysis. The Sep-Pak(®) C18 cartridges extraction procedure was selected since it generated analytical signals 5 times higher than those obtained with the two different Oasis(®) HLB cartridges extraction procedures. The method has shown to be selective for the isolation of selected OPs as well as to the chosen internal standard (ethion) in postmortem blood samples. Calibration curves between 50 and 5000 ng/mL were prepared using weighted linear regression models (1/x(2)). It was not possible to establish a working range for fenthion by GC-µECD due to the lower sensitivity of the detector to this compound, whereas for pirimiphos-methyl it was set between 500 and 5000 ng/mL. The limit of quantitation was established at 50 ng/mL for all analytes, except for pirimiphos-methyl by GC-µECD analysis (500 ng/mL). The average extraction efficiency ranged from 72 to 102%. The developed methods were considered robust and fit for the purpose, and had already been adopted in the laboratory routine analysis.