Browsing by Author "Costa, Suzel"
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- Desenvolvimento e validação de um método para a determinação de canabinóides em urina por microextracção em seringa empacotada e GC-MSPublication . Rosendo, Luana; Rosado, Tiago; Oliveira, Patrik; Simão, Ana; Margalho, Cláudia; Costa, Suzel; Passarinha, Luís; Gallardo, Eugenia; Barroso, MárioDe acordo com o Observatório Europeu da Droga e da Toxicodependência, no último ano (dados de junho de 2022), existiam aproximadamente 22,2 milhões consumidores de canábis na Europa. A urina é uma das amostras mais utilizadas para a deteção e quantificação de canabinóides. (...)
- Determinação de canabinóides em amostras de urina por microextração em seringa empacotada e cromatografia gasosa-espetrometria de massaPublication . Rosendo, Luana; Rosado, Tiago; Oliveira, Patrik; Antunes, Cal; Anjos, O; Margalho, Cláudia; Costa, Suzel; Passarinha, Luís; Barroso, Mário; Gallardo, EugeniaA canábis é a substância ilícita mais frequentemente consumida a nível mundial. Em laboratórios de análise de drogas. A urina é uma das amostras mais utilizadas para a deteção de canabinóides. Nesta matriz biológica é possí -tretahidrocanabinol (THC), principal composto psicoativo presente na cannabis, o ácido 11-nor-9-carboxi- -tretahidrocanabinol (THC-COOH) e ainda o 11-hidroxi- -tetrahydrocannabiol (11-OH-TCH) que são utilizados como marcadores de consumo desta droga de abuso. Este trabalho descreve o desenvolvimento e validação de um método para a determinação de cannabidiol (CBD), canabinol (CBN), THC, 11-OH-THC e THC-COOH em urina com recurso à MEPS e à cromatografia gasosa acoplada à espectrometria de massas. Após otimização, a metodologia foi validada seguindo normas internacionais de validação para bioanálise. Foi obtida uma linearidade de 1-400 ng/mL para o THC e CBD, de 5-400 ng/mL para CBN e 11-OH-THC e de 10-400 ng/mL para THC-COOH, com um coeficiente de correlação em todos os casos superior a 0,99. As precisões e exatidão inter-dia, intra-dia e intermedia obtidas tiveram coeficientes de variação abaixo dos 15% e uma exatidão inferior ou igual a 15% para todos os compostos em estudo. As recuperações obtidas variaram entre 26% a 85%. Os resultados obtidos permitem afirmar que a técnica proposta apresenta uma excelente sensibilidade (1-10 ng/mL). O método desenvolvido foi ainda aplicado a amostras de indivíduos com suspeita de consumo de canábis. É necessário destacar que o procedimento descrito é o primeiro trabalho que recorre à MEPS combinada com a GC-MS para quantificação de canabinóides em amostras de urina.
- Differentiation of selegiline metabolites and illicit methamphetamine and amphetamine use in elderly postmortem cases: Insights from LC-MS/MS and immunoassay techniquesPublication . Costa, Suzel; Rosendo, Luana M.; Barroso, Mário; Franco, João MiguelAbstract: Introduction: In forensic toxicology, distinguishing between pharmaceutical metabolites and illicit substances is crucial for accurate case interpretation. This study explores two post-mortem cases involving elderly individuals where methamphetamine and amphetamine were detected, raising initial concerns about illicit drug use. Aims: To demonstrate the application of liquid chromatography-tandem mass spectrometry (LC-MS/MS) and immunoassay techniques in differentiating between selegiline metabolites and illicit methamphetamine and amphetamine. Methods: Blood samples from three deceased elderly individuals (ages 91 and 89) were analyzed using LC-MS/MS for the quantitative detection of selegiline and metabolites. Initial screening revealed methamphetamine and amphetamine levels suggestive of potential illicit use. Immunoassay testing for dextro isomers (those associated with drug abuse) was subsequently performed to differentiate between isomers. Results and Discussion: LC-MS/MS analysis confirmed selegiline in both cases, with methamphetamine and amphetamine detected. Immunoassay results were negative for dextro isomers, indicating that the detected substances were L-isomers, which is consistent with selegiline metabolism rather than illicit use. Conclusion: This study highlights the critical role of combining LC-MS/MS and immunoassay techniques in forensic toxicology. The negative immunoassay results for dextro isomers clarified that the methamphetamine and amphetamine present were metabolic byproducts of selegiline therapy. Accurate differentiation between therapeutic and illicit substances is essential to avoid misinterpretation, particularly in elderly individuals, where illicit drug use is infrequent. These findings emphasize the need for comprehensive analytical approaches in forensic investigations to ensure accurate and reliable results.
- Fatal poisoning by Hemlock water dropwort roots (Oenanthe Crocata )Publication . Costa, Suzel; Franco, João; Barroso, Mário; Carvalho, S.; Fonseca, SuzanaIntrodution : This report describes the history and investigation of a suspected plant poisoning event in Portugal, involving the death of two adult males, who have mistakenly ingested Hemlock water dropwort roots Oenanthe crocata during a 36 h resistance path in May 2017 in Santarém Portugal Six hours after beginning the path, they have called to emergency services for assistance because they suddenly become unwell reporting plants ingestion and describing that they felt nauseated, vomits, seizures and disorientation Both were found dead a few hours later in a rural area In their backpacks, in addition to food supplies, they had fennel and spearmint that were probably picked up on the route Further investigations by police authorities found that during that morning they shared several photos in social media, including screenshots of wild parsnips Pastinaca sativa.
- High concentrations of nordiazepam may impair the detection of benzoylecgonine by GC-MS with derivatizationPublication . Costa, Suzel; Rosendo, Luana M.; Barroso, Mário; Gallardo, EugeniaIntroduction: Forensic toxicology plays a pivotal role in legal investigations, particularly in detecting substances in biological samples. However, the simultaneous presence of multiple substances can pose analytical challenges. For instance, nordiazepam, a major metabolite of some benzodiazepines, can interfere with the detection of benzoylecgonine, a primary metabolite of cocaine, when using gas chromatography-mass spectrometry (GC-MS) with N- methyl-N-(trimethylsilyl) trifluoroacetamide (MSTFA) derivatization. This interference could result in false negatives for benzoylecgonine detection. Aims: This study aims to assess whether N-methyl-N-(tert-butyldimethylsilyl)-trifluoroacetamide (MBDSTFA) derivatization can reduce interference from nordiazepam, thereby improving the detection and quantification of benzoylecgonine in biological samples. Methods: Solid phase extraction (SPE) was carried out on post-mortem blood samples using Oasis® MCX columns. Microwave derivatization with MSTFA or MBDSTFA followed after the extracts were evaporated. Results and discussion: Two derivatization reagents, MSTFA and MBDSTFA, were compared using GC-MS to evaluate their effectiveness. For this assessment, both the limit of detection (LOD) and limit of quantification (LOQ) for benzoylecgonine in this chromatographic method were 10 and 25 ng/mL, respectively. MBDSTFA derivatization significantly reduced analytical interference between nordiazepam and benzoylecgonine. In contrast, MSTFA derivatization resulted in substantial interference at high concentrations of nordiazepam, potentially leading to false negatives for cocaine detection. These findings highlight the superior performance of MBDSTFA in complex toxicological analyses. Conclusion: MBDSTFA derivatization is more effective than MSTFA for minimizing interference in the detection of benzoylecgonine in the presence of nordiazepam. This method enhances the specificity of forensic toxicological analyses and helps prevent false negatives for detecting cocaine consumption through its principal metabolite, thereby supporting more reliable legal and clinical decisions.
- Impacto da Derivatização Química na Deteção de Metabolitos de Cocaína na presença de BenzodiazepinasPublication . Costa, Suzel; Rosendo, Luana; Barroso, Mário; Gallardo, EugeniaA toxicologia forense desempenha um papel crucial em investigações legais, proporcionando informações essenciais sobre a presença e o impacto de várias substâncias em amostras biológicas. No entanto, esta área enfrenta desafios significativos devido a artefactos e interferências que podem dificultar a interpretação dos resultados. Este estudo aborda os desafios analíticos decorrentes da presença simultânea de cocaína e tranquilizantes benzodiazepínicos, especificamente o nordiazepam, em amostras biológicas. De facto, o nordiazepam, uma importante benzodiazepina, pode interferir na deteção e quantificação da benzoilecgonina, o principal metabolito da cocaína, quando se utiliza a cromatografia gasosa acoplada à espectrometria de massa (GC-MS). Recorreu-se à extração de fase sólida (SPE) em amostras de sangue post-mortem, usando colunas Oasis® MCX. Após a evaporação dos extratos, procedeu-se à derivatização por micro-ondas com MSTFA (N-metil-N-(trimetilsilil)trifluoroacetamida) ou MBDSTFA (N-metil-N-(terc-butildimetilsilil)-trifluoroacetamida). A análise foi realizada por cromatografia gasosa acoplada a um detetor de massa. Os resultados demonstraram que com a derivatização por MSTFA a presença de nordiazepam causava interferências significativas na deteção de benzoilecgonina, dificultando a confirmação qualitativa deste último composto. Este fenómeno foi evidenciado em cromatogramas onde picos cromatográficos correspondentes a fragmentos iónicos da benzoilecgonina foram observados mesmo quando apenas o nordiazepam foi injetado. Por outro lado, ao utilizar MBDSTFA como reagente derivatizante, não houve interferência significativa entre nordiazepam e benzoilecgonina às concentrações de 10 ng/mL e 25 ng/mL (limite de deteção e quantificação, respetivamente, da benzoilecgonina), ao contrário do observado com a derivatização por MSTFA. Este estudo destaca a necessidade de procedimentos de derivatização adequados de modo a diminuir o número de falsos negativos nos ensaios toxicológicos e enfatiza a importância de metodologias confiáveis em investigações forenses. A implementação de processos de validação rigorosos e o uso de agentes de derivatização alternativos, quando necessário, são cruciais para evitar interferências que prejudiquem a correta identificação dos tóxicos. As conclusões apresentadas contribuem para uma melhor compreensão das limitações da toxicologia forense, oferecendo recomendações práticas para aumentar a robustez das análises toxicológicas em casos envolvendo a cocaína.
- The Determination of Cannabinoids in Urine Samples Using Microextraction by Packed Sorbent and Gas Chromatography-Mass SpectrometryPublication . Rosendo, Luana M.; Rosado, Tiago; Oliveira, Patrik; Simão, Ana Y.; Margalho, Cláudia; Costa, Suzel; Passarinha, Luís A.; Barroso, Mário; Gallardo, EugeniaCannabis is the most consumed illicit drug worldwide, and its legal status is a source of concern. This study proposes a rapid procedure for the simultaneous quantification of Δ9-tetrahydrocannabinol (THC), 11-hydroxy-Δ9-tetrahydrocannabinol (11-OH-THC), 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THC-COOH), cannabidiol (CBD), and cannabinol (CBN) in urine samples. Microextraction by packed sorbent (MEPS) was used to pre-concentrate the analytes, which were detected by gas chromatography–mass spectrometry. The procedure was previously optimized, and the final conditions were: conditioning with 50 µL methanol and 50 µL of water, sample load with two draw–eject cycles, and washing with 310 µL of 0.1% formic acid in water with 5% isopropanol; the elution was made with 35 µL of 0.1% ammonium hydroxide in methanol. This fast extraction procedure allowed quantification in the ranges of 1–400 ng/mL for THC and CBD, 5–400 ng/mL for CBN and 11-OH-THC, and 10–400 ng/mL for THC-COOH with coefficients of determination higher than 0.99. The limits of quantification and detection were between 1 and 10 ng/mL using 0.25 mL of sample. The extraction efficiencies varied between 26 and 85%. This analytical method is the first allowing the for determination of cannabinoids in urine samples using MEPS, a fast, simple, and low-cost alternative to conventional techniques
- Toxicological analysis of cocaine adulterants in blood samplesPublication . Gameiro, Rui; Costa, Suzel; Barroso, Mário; Franco, João; Fonseca, SuzanaBackground & Objectives According to the European Drug Report of 2017, cocaine was the second most widely used drug in 2016, with 3.5 million consumers between 15 and 64 years old. This pattern of consumption also occurs in Portugal (2012). Adulterants are pharmacologically active substances developed for medical purposes (analgesics, local anesthetics, antihistamines, anthelmintics and others). However, there is little knowledge about their influence in the human body when there is concomitant use with cocaine, such as an increase of cocaine toxicity even in non-toxic concentrations. The objective of this work was to validate a method that allows the identification, confirmation and quantification of cocaine adulterants in blood samples collected in vivo or post-mortem. The studied substances (atropine, phenacetin, hydroxyzine, ketamine, lidocaine and tetramisole) were selected taking into account the literature review, the analytical standards and the technical conditions. It is also intended to make a retrospective study of the prevalence of these substances in cases with a positive result for cocaine or its metabolites, as well as their relative concentrations.