Navegando por Autor "Aquino Neto, Francisco Radler de"

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Comprehensive analysis by liquid chromatography Q‐Orbitrap mass spectrometry : fast screening of peptides and organic molecules.
(2018) Sardela, Vinícius Figueiredo; Martucci, Maria Elvira Poleti; Araujo, Amanda Lessa Dutra de; Leal, E. C.; Oliveira, D. S.; Carneiro, Gabriel Reis Alves; Deventer, K.; Eenoo, P. Van; Pereira, Henrique Marcelo Gualberto; Aquino Neto, Francisco Radler de
The number of substances nominally listed in the prohibited list of the World Anti‐ Doping Agency increases each year. Moreover, many of these substances do not have a single analytical target and must be monitored through different metabolites, artifacts, degradation products, or biomarkers. A new analytical method was developed and validated for the simultaneous analysis of peptides and organic molecules using a single sample preparation and LC‐Q‐HRMS detection. The simultaneous analysis of 450 target molecules was performed after cleanup on a mixed‐mode solid‐phase extraction cartridge, combined with untreated urine. The cleanup solvent and reconstitution solvent were the most important parameters for achieving a comprehensive sample preparation approach. A fast chromatographic run based on a multistep gradient was optimized under different flows; the detection of all substances without isomeric coelution was achieved in 11 minutes, and the chromatographic resolution was considered a critical parameter, even in high‐resolution mass spectrometry detection. The mass spectrometer was set to operate by switching between positive and negative ionization mode for FULL‐MS, all‐ion fragmentation, and FULL‐MS/MS2 . The suitable parameters for the curved linear trap (c‐trap) conditions were determined and found to be the most important factors for the development of the method. Only FULL‐MS/ MS2 enables the detection of steroids and peptides at concentrations lower than the minimum required performance levels set by World Anti‐Doping Agency (1 ng mL−1 ). The combination of the maximum injection time of the ions into the c‐trap, multiplexing experiments, and loop count under optimized conditions enabled the method to be applied to over 10 000 samples in only 2 months during the 2016 Rio Summer Olympic and Paralympic Games. The procedure details all aspects, from sample preparation to mass spectrometry detection. FULL‐MS data acquisition is performed in positive and negative ion mode simultaneously and can be applied to untargeted approaches.
Pharmacokinetic study of xylazine in a zebrafsh water tank, a human‑like surrogate, by liquid chromatography Q‑Orbitrap mass spectrometry.
(2020) Mato, Rebecca Rodrigues; Martucci, Maria Elvira Poleti; Anselmo, Carina de Souza; Aquino Neto, Francisco Radler de; Pereira, Henrique Marcelo Gualberto; Sardela, Vinícius Figueiredo
Purpose: This study aims to investigate a zebrafish (Danio Rerio) water tank (ZWT) as an alternative model for the study of the metabolism of xylazine. Methods: The ZWT approach for the study of metabolism consisted of two aquariums, where 18 fish and xylazine were added into the first tank. The second one, with 18 fish without drug, served as a negative control. The samples were submitted to a comprehensive analytical method developed for doping control purposes by liquid chromatography (LC) coupled with high-resolution mass spectrometry (HRMS) operating in five different acquisition modes. Glycoconjugate metabolites were evaluated indirectly by extracting the samples with and without the enzymatic hydrolysis step using β-glucuronidase. Results: In total, 11 phase I and II metabolites were detected and characterized, of which four were previously described for humans and two for horses, and five metabolites were described for the first time. The main metabolites were 4-hydroxylated (M2) and oxygenated (M1) derivatives. Both metabolites were suggested as analytical targets for xylazine misuse. Around 79% of para- and meta-hydroxylated derivatives were in glycoconjugate form, whereas for oxo-hydroxylated and sulfone-hydroxylated derivatives of xylazine, around 83% and 70% were metabolized to the glycoconjugate form, respectively. Conclusions: Xylazine was the subject of extensive metabolism in zebrafish. 4-Hydroxylated (M2) and oxygenated (M1) derivatives were the most abundant phase I metabolites as the main targets for doping control.