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- MDMA intoxication in a potential organ donor with cardiac arrestPublication . Castro, André Lobo; Tarelho, Sónia; Almeida, Dina; Sousa, Lara; Franco, João; Teixeira, Helena M.Amphetamine and its derivatives’ consumption is still an important public health issue, namely in terms of compounds variability and disposition to consumers. However, some of them, like MDMA, still live in the illicit market, with continuous success. Nevertheless, there is always new information and data on MDMA intoxication, both in vivo and in post-mortem context. The authors report an intoxication case with MDMA, in an 18 years old male, considered a potential organ donor after a cardiac arrest. Whole blood samples were collected in vivo, at the Emergency Room (ER), and post-mortem, at the National Institute of Legal Medicine and Forensic Sciences. After a general screening procedure, samples were extracted by SPE (OASIS® MCX), followed by GC-MS analysis. The whole blood post-mortem sample was positive for lidocaine (< 500 ng/mL), compatible with the ER intervention, and positive for MDMA (2278 ng/mL) and MDA (49 ng/mL), while whole blood samples collected in vivo (during the maintenance of the individual under advanced life support), were positive for MDMA (504 ng/mL to 1918 ng/mL) and MDA (20 ng/mL to 89 ng/mL). Samples were negative for other substances, namely ethanol, other drugs of abuse and medicines.Results interpretation is pivotal to understand the behaviour of the substance. Thus, in this case, MDMA post-mortem behaviour should be carefully evaluated, considering as possible influencers, in the specific context of the case, the time lapse between death verification, maintenance of the advanced life support and body manipulation for organ collection purposes. Also referred and discussed is the ante-mortem/post-mortem ratio of MDMA obtained values, compared with literature references. There is no doubt that death was due to MDMA intoxication, but information from the analysis performed on the in vivo samples suggests that this type of sample should also be considered, in a complementary role, whenever possible.
- Illicit fentanyl intoxication: a case reportPublication . Tarelho, Sónia; Stasyuk, Mykola; Castro, André Lobo; Melo, Paula; Sousa, Lara; Teixeira, Helena M.; Franco, João
- Simultaneous analysis of some club drugs in whole blood using solid phase extraction and gas chromatography–mass spectrometryPublication . Castro, André Lobo; Tarelho, Sónia; Silvestre, Armando; Teixeira, Helena M.The use of psychoactive substances to improve social relations and increase body energy, in Rave Culture, has raised many legal and health public concerns, both for illicit trade and consumption. Therefore, forensic toxicology plays an important role in this area, mainly linked to the detection and quantitation of these substances, both in vivo and in post-mortem samples. In fact, at the moment, forensic sciences have been under public authorities’ scrutiny and critical look, due to the increasing attention of the media and public opinion, always applying for the use of scientific knowledge to help solving forensic cases. However, forensic toxicology results are only reliable to solve legal cases if all the analytical methodologies used are appropriately validated. In this work, a methodology for the extraction and analysis of 7-aminoflunitrazepam, buprenorphine, flunitrazepam, ketamine, methadone, phencyclidine (PCP) and d-propoxyphene was developed for whole blood samples, with Solid-Phase Extraction (SPE), using OASIS MCX SPE columns, and gas chromatography coupled to mass spectrometry. The procedure presented here proved to be reliable, specific, selective and sensitive, with good LODs and LOQs and good precision.The adoption of a SPE procedure with an automatic SPE extraction device, allowed an increased level of automation in sample treatment, being contemporarily less time-consuming, increasing productiveness, and allowing good recovery and appropriate selectivity being, also, simple and reproducible. The simultaneous detection and quantitation of all compounds by the same extraction and detection methodology is crucial and has a great potential for forensic toxicology and clinical analysis.
- Antidepressants detection and quantification in whole blood samples by GC–MS/MS, for forensic purposesPublication . Truta, Liliana; Castro, André Lobo; Tarelho, Sónia; Costa, Pedro; Sales, M. Goreti F.; Teixeira, Helena M.Depression is among the most prevalent psychiatric disorders of our society, leading to an increase in antidepressant drug consumption that needs to be accurately determined in whole blood samples in Forensic Toxicology Laboratories. For this purpose, this work presents a new gas chromatography tandem mass spectrometry (GC–MS/MS) method targeting the simultaneous and rapid determination of 14 common Antidepressants in whole blood: 13 Antidepressants (amitriptyline, citalopram, clomipramine, dothiepin, fluoxetine, imipramine, mianserin, mirtazapine, nortryptiline, paroxetine, sertraline, trimipramine and venlafaxine) and 1 Metabolite (N-desmethylclomipramine). Solid-phase extraction was used prior to chromatographic separation. Chromatographic and MS/MS parameters were selected to improve sensitivity, peak resolution and unequivocal identification of the eluted analyte. The detection was performed on a triple quadrupole tandem MS in selected ion monitoring (SIM) mode in tandem, using electronic impact ionization. Clomipramine-D3 and trimipramine-D3 were used as deutered internal standards. The validation parameters included linearity, limits of detection, lower limit of quantification, selectivity/ specificity, extraction efficiency, carry-over, precision and robustness, and followed internationally accepted guidelines. Limits of quantification and detection were lower than therapeutic and subtherapeutic concentration ranges. Overall, the method offered good selectivity, robustness and quick response (<16 min) for typical concentration ranges, both for therapeutic and lethal levels.
- Comparison of endogenous GHB concentrations in blood and hair in death cases with emphasis on the post mortem intervalPublication . Castro, André Lobo; Tarelho, Sónia; Dias, Mário; Reis, Flávio; Teixeira, Helena M.Gamma-hydroxybutyric acid (GHB) is an endogenous compound which has a story of clinical use and illicit abuse since the 1960’s. The possibility to use a multi-sample approach of GHB evaluation, including whole blood and hair, to better characterize a forensic toxicology case and evaluate a possible causal association with the death, is an exciting up-to-date issue. In addition, its post-mortem behaviour, namely regarding degradation and metabolism, has been increasingly investigated as a putative biomarker for post-mortem interval (PMI) estimation. Thus, In order to contribute to clarify this specific aspect, whole blood and hair post-mortem GHB levels were evaluated in thirty two real cases with previous information on death and autopsy data. The results obtained suggest that the PMI (until 5 days between death and sampling) influences GHB whole blood concentration, but not GHB levels in hair samples. No differences were encountered for the other parameters evaluated, including age, gender, cause of death and presence or absence of substances. This study brings new insights regarding the usefulness of GHB levels in forensic toxicology, which might be further strengthened with larger, but comparable, studies from other laboratories and institutions in the context of legal medicine.
- Analysis of organophosphorus pesticides in whole blood by GC-MS-μECD with forensic purposesPublication . Valente, Nuno I.P.; Tarelho, Sónia; Castro, André Lobo; Silvestre, Armando; Teixeira, Helena M.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/x2). 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.
- A fast and reliable method for GHB quantitation in whole blood by GC–MS/MS (TQD) for forensic purposesPublication . Castro, André Lobo; Tarelho, Sónia; Dias, Mário; Reis, Flávio; Teixeira, Helena M.Gamma-Hydroxybutyric Acid (GHB) is an endogenous compound with a story of clinical use since the 1960’s. However, due to its secondary effects, it has become a controlled substance, entering the illicit market. A fully validated, sensitive and reproducible method for the quantification of GHB by methanolic precipitation and GC-MS/MS (TQD) in whole blood is presented. Using 100 µL of whole blood, obtained results included a LOD and LLOQ of 0.1 mg/L and a recovery of 86% in a working range between 0.1 and 100 mg/L. This method is sensitive and specific to detect the presence of GHB in small amounts of whole blood (both ante-mortem or post-mortem), and is, to the authors’ knowledge, the first GC-MS-MS TQD method that uses different precursor ions and product ions for the identification of GHB and GHB-D6 (internal standard). Hence, this method may be especially useful for the study of endogenous values in this biological sample.
- Gamma-hydroxybutyric acid endogenous production and post-mortem behaviour – The importance of different biological matrices, cut-off reference values, sample collection and storage conditionsPublication . Castro, André Lobo; Dias, Mário; Reis, Flávio; Teixeira, Helena M.Gamma-Hydroxybutyric Acid (GHB) is an endogenous compound with a story of clinical use, since the 1960's. However, due to its secondary effects, it has become a controlled substance, entering the illicit market for recreational and “dance club scene” use, muscle enhancement purposes and drug-facilitated sexual assaults. Its endogenous context can bring some difficulties when interpreting, in a forensic context, the analytical values achieved in biological samples. This manuscript reviewed several crucial aspects related to GHB forensic toxicology evaluation, such as its post-mortem behaviour in biological samples; endogenous production values, whether in in vivo and in post-mortem samples; sampling and storage conditions (including stability tests); and cut-off reference values evaluation for different biological samples, such as whole blood, plasma, serum, urine, saliva, bile, vitreous humour and hair. This revision highlights the need of specific sampling care, storage conditions, and cut-off reference values interpretation in different biological samples, essential for proper practical application in forensic toxicology.