Percorrer por autor "Pelixo, Rodrigo"
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- Determination of Arylcyclohexylamines in Biological Specimens: Sensors and Sample Pre-Treatment ApproachesPublication . Pelixo, Rodrigo; Barroso, Mário; Gallardo, Eugenia; Rosado, TiagoArylcyclohexylamine (ACH) compounds represent a predominant faction within new psychoactive substances. Due to their powerful dissociative effects, they are used in recreational contexts but also in situations of drug-facilitated sexual assault, and therefore, they are a constant target of analysis by forensic experts. In recent years, their consumption has been notably high, especially the use of ketamine, presenting daily challenges for laboratories in the determination of this and other ACH analogues. This review comprises the recent strategies that forensic specialists use to identify and quantify ACH compounds in the laboratory with more traditional analytical techniques and technology, and on the point-of-care testing via sensor technology. The study focuses on analogues of phencyclidine (PCP), ketamine, and eticyclidine, highlighting the consistent need for higher sensitivity in the analysis of various samples collected from real cases and simulations of possible matrices. The review also emphasises the ongoing research to develop more sensitive, quicker, and more capable sensors.
- Determination of ketamine and norketamine in hair samples by µ-QuEChERS and gas chromatography coupled to tandem mass spectrometryPublication . Pelixo, Rodrigo; Barroso, Mário; Rosado, Tiago; Gallardo, EugeniaKetamine has gained popularity in Europe as a new psychoactive substance due to its dissociative effects, which are sought after by users at raves, for unprescribed treatment of psychological issues, and in drug-facilitated crimes. Forensic experts often face challenges in proving drug use, and hair offers distinct advantages as a sample, revealing both long-term consumption and recent abuse. However, due to its complex nature, hair requires pretreatment to remove interferences and enhance analytical sensitivity. This study employs a miniaturised version of the “Quick, Easy, Cheap, Rugged, and Safe” (QuEChERS) extraction method, commonly used in food and environmental analyses. The method uses 1 mL of 5 % formic acid in acetonitrile and 250 mg ammonium formate as solvent and salt partitioning agents, along with 50 mg magnesium sulphate and 10 mg primary-secondary amine for dispersive solid-phase extraction. After this clean-up process, samples were analysed using gas chromatography coupled with tandem mass spectrometry. Following optimisation, the method was validated for detecting ketamine and its primary metabolite, norketamine. A limit of detection of 0.01 ng/mg was achieved for ketamine, and 0.8 ng/mg for norketamine, with limits of quantification of 0.05 ng/mg and 0.8 ng/mg, respectively. This established a working range of 0.05–5 ng/mg for ketamine and 0.8–5 ng/mg for norketamine. Recovery rates ranged from 47–76 % for ketamine and 14–27 % for norketamine. The method was then applied to real samples from drug users, proving the effectiveness of the µ-QuEChERS technique as a sustainable clean-up method. Despite its miniaturisation, it retained the performance of the original QuEChERS protocol and allowed obtaining high sensitivity, enabling analyte detection at a concentration below the Society of Hair Testing’s cut-off value of 0.2 ng/mg.
- Microextraction action by packed sorbent in forensic drug analysisPublication . Rosado, Tiago; Pelixo, Rodrigo; Pires, Bruno; Catarro, João Miguel; Rosendo, Luana M.; Brinca, Ana T.; Antunes, Mónica; Soares, Sofia; Simão, Ana Y.; Barroso, Mário; Gallardo, EugeniaMicroextraction by packed sorbent (MEPS) efficiently combines extraction, pre-concentration, and cleanup in a single device comprising two parts: the MEPS syringe and the packed sorbent bed1. MEPS has been used for several bioanalytical applications, including extraction of endogenous metabolites, biomarkers, and drugs from biological samples. It is particularly useful in metabolomics and pharmacokinetic studies2,3. Regarding MEPS applicability to forensic toxicology, urine is the most used specimen, followed by oral fluid (despite of its relatively high viscosity). Protein precipitation followed by centrifugation and with, or without dilution of the supernatant is the most commonly reported approach. The most detected compounds in forensic settings using MEPS are drugs of abuse [opiates and opioids (26%), cocaine (13%) cathinones (11%), dissociative hallucinogens (11%), cannabinoids and amphetamines (9% each) and other drugs (10%)] and medicinal drugs [antidepressants (9%), benzodiazepines/Z drugs (4%)]. MEPS was also applied to a beverage for forensic purposes e.g. to evaluate its composition in drug-facilitated crimes. An important feature in MEPS is the miniaturization of the sorbent. A careful selection of the sorbent will allow working with complex matrices, separating the target analytes from interferences and improve recoveries. The most widely selected sorbent was the silica based C18 that is a popular reversed-phase material (41%). Starting in the 2000s, new modifications of sorbents appeared. Overall, what the future holds for MEPS applications in forensic toxicology is promising, and ongoing research and technological advancements are likely to enhance the capabilities of MEPS approaches, making this technique an increasingly valuable tool for toxicological investigations.
- Sensors in the Detection of Abused Substances in Forensic Contexts: A Comprehensive ReviewPublication . Rosendo, Luana M.; Antunes, Mónica; Simão, Ana Y.; Brinca, Ana Teresa; Catarro, Gonçalo; Pelixo, Rodrigo; Martinho, João; Pires, Bruno; Soares, Sofia; Cascalheira, José Francisco; Passarinha, Luís; Rosado, Tiago; Barroso, Mário; Gallardo, Eugeniaorensic toxicology plays a pivotal role in elucidating the presence of drugs of abuse in both biological and solid samples, thereby aiding criminal investigations and public health initiatives. This review article explores the significance of sensor technologies in this field, focusing on diverse applications and their impact on the determination of drug abuse markers. This manuscript intends to review the transformative role of portable sensor technologies in detecting drugs of abuse in various samples. They offer precise, efficient, and real-time detection capabilities in both biological samples and solid substances. These sensors have become indispensable tools, with particular applications in various scenarios, including traffic stops, crime scenes, and workplace drug testing. The integration of portable sensor technologies in forensic toxicology is a remarkable advancement in the field. It has not only improved the speed and accuracy of drug abuse detection but has also extended the reach of forensic toxicology, making it more accessible and versatile. These advancements continue to shape forensic toxicology, ensuring swift, precise, and reliable results in criminal investigations and public health endeavours.