Analysis of corticosteroids in samples of animal origin using QuEChERS and ultrahigh-performance liquid chromatography coupled to high-resolution mass spectrometry.

A rapid and sensitive method for the confirmatory analysis of 8 synthetic corticosteroids (betamethasone, dexamethasone, prednisolone, 6 methyl prednisolone, triamcinolone, flumethasone, beclomethasone, fluocinolone acetonide) is proposed. The method is useful for detecting illegal treatments in different animal species. It consists of an extraction and clean-up using the Quick Easy Cheap Effective Rugged Safe (QuEChERS) strategy. Quantitative determination is achieved by ultra-high performance liquid chromatography coupled to high-resolution mass spectrometry with heated electrospray ionization in negative mode. Quantification is performed using surrogate matrix matched standard calibration curve with dexamethasone-D4 as the internal standard. The method was validated for analyzing liver samples according to the criteria established by Decision 2002/657/EC. Linearity was assessed in the 1-10 μg kg-1 range and linear correlation coefficients were over 0.99 for all the analytes. CCα ranged from 0.04 to 0.16 μg kg-1 for substances without maximum residue limit. The method allows confident quantification and confirmation of corticosteroids in liver samples, and its simplicity makes it suitable for analyzing large numbers of samples

Identificación y cuantificación de adulterantes de sustancias psicoactivas

Treballs Finals de Grau de Química, Facultat de Química, Universitat de Barcelona, Any: 2013, Tutora: Dra. Encarnación MoyanoThe increased consumption of psychoactive substances and the appearance of new substances (Legal Highs) represent an interesting social topic for authorities such as the NGO Cruz Roja Joventut and some research centers such as the UB. The innovation and lack of knowledge is a problem when facing the challenge of identifying and quantifying psychoactive substances. For this reason, it is a very attractive topic for analytical studies. In this final project work, a database of psychoactive substances has been created in order to accelerate the process of identification of these substances in samples obtained from consumers. Databases are essential tools for the identification and confirmation of compounds as they provide quick and accurate information about the m/z of the substances, their possible fragmentation and working mode, as well as many other properties. The created database contains 164 psychoactive substances with the corresponding parameters for their study by FIA-MS. This allowed the identification of substances in spite of the lack of standards..