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- Development and validation of a multi-substance method for routine analysis of pesticides in post-mortem samples by UPLC-MS/MSPublication . Matos, Francisco; Barroso, Mário; Antunes, Mónica; Franco, João; Fonseca, SuzanaPesticides play an important role in forensic toxicology and are usually classified as a single class of chemicals, but in fact there are several different types of compounds, including organophosphates, carbamates, pyrethroids or organochlorines, among others, with different toxicities. Pesticide analysis in post-mortem samples can be difficult due to the complexity of the samples and to the high toxicity of these compounds. The aim of this study was to develop and validate an easy to use, sensitive, and robust method, using ultra-performance liquid chromatography-tandem mass spectrometry to be incorporated in the routine flow for more than fifty pesticide analysis in post-mortem blood. The developed analytical method was fully validated according to the guiding principles of the ANSI/ASB Standard 036 and applied to routine post-mortem samples, being already detected more than 15 positive cases. This UPLC-MS/MS method is useful and a powerful tool in a toxicology lab because it is fast, simple, effective, and trustworthy. This method is able to detect and analyse pesticides in post-mortem samples. It is set to use for routine analysis and successfully applied to intoxication cases.
- Desenvolvimento e validação de um método analítico para a determinação de canabinóides em amostras de fluido oral por LC-MS/MSPublication . Antunes, Mónica; Simões, Susana; Fonseca, Suzana; Franco, João; Gallardo, Eugenia; Barroso, MárioA canábis é a droga de abuso mais consumida na Europa, pelo que várias metodologias analíticas têm sido desenvolvidas para a quantificação dos seus componentes em matrizes biológicas, especialmente sangue e urina. No entanto, cada vez mais se está a reconhecer a importância do estudo de matrizes biológicas não-convencionais, nomeadamente cabelo e fluido oral (ou saliva) – os seus procedimentos de recolha não são invasivos e estas amostras fornecem informações complementares sobre o uso de drogas, permitindo o controlo da exposição recente (saliva) e de médio a longo prazo (cabelo). Desta forma, foi desenvolvida uma metodologia analítica para a determinação e quantificação de tetrahidrocanabinol (THC), 11-hidroxi-tetrahidrocanabinol (THC-OH), 11-carboxitetrahidrocanabinol (THC-COOH), canabinol (CBN) e canabidiol (CBD) em amostras de saliva por cromatografia líquida acoplada à espectrometria de massa em tandem (LC-MS/MS). Segundo as Mandatory Guidelines for Federal Workplace Drug Testing Programs, o cut-off de THC em amostras de saliva é 2 ng/mL, exigindo um procedimento de extração otimizado e a utilização de uma técnica cromatográfica sensível. Resumidamente, a 200 μL de saliva foi adicionado o padrão interno, e as amostras foram submetidas a precipitação proteica com uma mistura de metanol/acetonitrilo (80:20, v/v) refrigerada. Depois de centrifugados, os extratos foram evaporados até à secura, reconstituídos em metanol, e 5 μL foram injetados no equipamento UPLC-QTRAP-MS 6500+ (SCIEX®), numa corrida de 14 minutos. A análise foi efetuada em modo MRM com duas transições para cada composto e uma transição para cada padrão interno. Os métodos foram validados de acordo com as diretrizes da norma ANSI/ASB 036, tendo sido estudados os parâmetros supressão iónica, interferentes, linearidade, precisão e exatidão, carryover, limites de deteção e quantificação, efeito de diluição e estabilidade das amostras extraídas. Todos os estudos destes parâmetros apresentaram resultados satisfatórios, e o método foi aplicado com sucesso a amostras reais. O método desenvolvido mostrou-se fácil, rápido, eficaz e robusto, estando apto para ser utilizado na rotina do laboratório, e sendo uma ferramenta complementar útil para o estudo do consumo recente de canabinóides.
- Documenting human exposure to cannabinoids using oral fluidPublication . Antunes, Mónica; Simões, Susana; Fonseca, Suzana; Franco, João Miguel; Gallardo, Eugenia; Barroso, MárioThe importance of studying non-conventional biological matrices such as oral fluid (OF) is increasingly being recognized. This sample presents several advantages, mainly related to its collection procedure: it is non-invasive, easy to perform by non-medical personnel, can be performed under supervision to prevent adulteration, and provides low biohazard risk. OF samples are more likely to contain parent drugs, reflecting recent drug use – a major advantage of this matrix1. A fast and robust analytical methodology was developed in OF samples for the determination of tetrahydrocannabinol (THC), 11-hydroxy-tetrahydrocannabinol (THC-OH), 11-carboxytetrahydrocannabinol (THC-COOH), cannabinol (CBN) and cannabidiol (CBD) by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS), aiming at documenting cannabis consumption. Briefly, 200-μL aliquots of OF were subjected to protein precipitation with a refrigerated methanol/acetonitrile mixture (80:20, v/v). After centrifugation, the extracts were evaporated to dryness, reconstituted in methanol, and 5-μL aliquots were injected into the UPLC-QTRAP-MS 6500+ (SCIEX®) system (in a 14-minute run). The analysis was carried out in MRM mode with two transitions for each compound and one transition for each internal standard. The method was validated according to the guidelines of ANSI/ASB 0362. Parameters such as ion suppression/enhancement, interferents, linearity, precision and accuracy, limits of detection and quantification, dilution integrity and stability were studied and showcased satisfactory results. The 2 ng/mL cut-off for THC3 was achieved, and the method was successfully applied to real samples (57.95- 898.28 ng/mL for THC; 0.17-4.09 ng/mL for THC-COOH; 1.26-44.57 ng/mL for CBN; 0.42-1007.86 ng/mL).
- Detection and quantification of selected cannabinoids in oral fluid samples by protein precipitation and LC-MS/MSPublication . Antunes, Mónica; Simões, Susana; Fonseca, Suzana; Franco, João; Gallardo, Eugenia; Barroso, MárioCannabis is the most widely consumed illicit drug worldwide. As consumption rates increase, partially due to the decriminalization of its use for medicinal and recreational purposes, analytical methods for monitoring different cannabinoids in several biological matrices have been developed. Herein, a simple and fast extraction procedure to extract natural cannabinoids from oral fluid (OF) samples was developed and fully validated according to the ANSI/ASB 2019 Standard Practices for Method Validation in Forensic Toxicology. Using only 0.2 mL of neat OF, the analytes [Δ9-tetrahidrocannabinol (THC), 11-hydroxy-Δ9-tetrahydrocannabinol (THC-OH), 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THC-COOH), cannabinol (CBN) and cannabidiol (CBD)] were extracted by protein precipitation with a mixture of methanol:acetonitrile (80:20, v/v); the extracts were centrifuged, evaporated to dryness and reconstituted in 100 µL of methanol. Analysis was performed by liquid chromatography coupled to tandem mass spectrometry (LC–MS/MS). The developed methodology produced linear results for all compounds, with working ranges of 0.1–50 ng/mL for THC, 0.5–50 ng/mL for THC-OH, CBN and CBD, and 0.05–1 ng/mL for THC-COOH. Ion suppression was observed for THC, CBN and CBD, which did not impair sensitivity considering the low limits of quantification (LOQs) and limits of detection (LODs) obtained (which varied between 0.05 and 0.5 ng/mL). The extraction procedure produced great recoveries, and the compounds were stable. No interferences were found, and the method proved to be extremely fast, selective, precise, and accurate for use in routine analysis. The method was successfully applied to authentic samples.
- Determination of biomarkers of cannabis consumption in hair samples: preliminary resultsPublication . Antunes, Mónica; Fonseca, Suzana; Simões, Susana; Franco, João; Gallardo, Eugenia; Barroso, MárioOver 96 million European adults are estimated to have consumed illicit drugs at some point in their lives, and cannabis is still the most consumed drug. The Portuguese data is obtained using surveys, but this type of study has several disadvantages, such as under or overestimation of consumption rates, which may lead to biased conclusions.Consequently, it is desirable that these studies are accompanied by drug monitoring in biological samples to circumvent the associated drawbacks.
- 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.
- 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.