Objective To establish a method that combines a series of techniques including Fourier transform infrared spectrum (FTIR), gas chromatography-mass spectrometry (GC-MS), high resolution mass spectrometry and nuclear magnetic resonance spectroscopy (NMR) for identification of unknown substances. Methods The unknown samples (off-white powder and yellow crystal) seized in the actual cases were detected by FTIR, GC-MS (methanol as solvent), high resolution mass spectrometry (methanol as solvent) and NMR (deuterated methanol as solvent). Results The mass spectrum characteristic ions of the main components in the samples measured by GC-MS were 219 (base peak), 363, 307, 304, 275, 145, 131 and 213 (base peak), 357, 301, 298, 269, 185, 171, 145 and 131, respectively. The accurate mass numbers [M+H] measured by high resolution mass spectrometry were 364.203 61 and 358.212 34, respectively. The unknown samples were identified as synthetic cannabinoid new psychoactive substances 4F-MDMB-BUTINACA and MDMB-4en-PINACA after data consultation and database retrieval and comparison, combined with infrared analysis and mass spectrometry data analysis, and their structures were confirmed by H-NMR. Conclusion The established multi-technology joint identification method can be used to identify 4F-MDMB-BUTINACA and MDMB-4en-PINACA in unknown samples. This method is fast, convenient, accurate, reliable and practical, and can provide reference for the identification of cases involving such substances in the future.
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http://dx.doi.org/10.12116/j.issn.1004-5619.2020.300501 | DOI Listing |
Int Endod J
January 2025
Department of Restorative Dentistry-Endodontics, Piracicaba Dental School, Universidade Estadual de Campinas, Piracicaba, São Paulo, Brazil.
Aim: Calcium silicate-based cements have been widely used in dentistry mainly due to their physicochemical and biological properties. Commercially available materials use radiopacifiers containing metals (bismuth, tantalum, tungsten and/or zirconium). To investigate volumetric changes, in vivo biocompatibility and systemic migration from eight commercially available materials, including powder/liquid and 'ready-to-use' presentations.
View Article and Find Full Text PDFMethods Mol Biol
January 2025
Analytic Biochemistry, Calculi and Manual Chemistry, Mass Spectrometry, ARUP Laboratories, Inc., Salt Lake City, UT, USA.
Metanephrines (metanephrine [MN] and normetanephrine [NMN]) are O-methylated metabolites derived from the catecholamines, epinephrine, and norepinephrine, respectively. High concentrations of metanephrines have been observed in individuals with pheochromocytoma, a neuroendocrine tumor. Measurement of metanephrines in urine is used to screen for the tumor.
View Article and Find Full Text PDFMethods Mol Biol
January 2025
Department of Food Quality and Nutrition, Research and Innovation Center, Fondazione Edmund Mach, San Michele all'Adige, Italy.
The final aim of metabolomics is the comprehensive and holistic study of the metabolome in biological samples. Therefore, the use of instruments that enable the analysis of metabolites belonging to various chemical classes in a wide range of concentrations is essential, without compromising on robustness, resolution, sensitivity, specificity, and metabolite annotation. These characteristics are crucial for the analysis of very complex samples, such as wine, whose metabolome is the result of the sum of metabolites derived from grapes, yeast(s), bacteria(s), and chemical or physical modification during winemaking.
View Article and Find Full Text PDFMethods Mol Biol
January 2025
Department of Medicine and Surgery, Proteomics and Metabolomics Unit, University of Milano-Bicocca, Vedano al Lambro, Italy.
Trapped ion mobility spectrometry (TIMS) using parallel accumulation serial fragmentation (PASEF) is an advanced analytical technique that offers several advantages in mass spectrometry (MS)-based lipidomics. TIMS provides an additional dimension of separation to mass spectrometry and accurate collision cross-section (CCS) measurements for ions, aiding in the structural characterization of molecules. This is especially valuable in lipidomics for identifying and distinguishing isomeric or structurally similar compounds.
View Article and Find Full Text PDFMethods Mol Biol
January 2025
Laboratory of Analytical Biochemistry & Metabolomics, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic.
A simple analytical workflow is described for gas chromatographic-mass spectrometric (GC-MS)-based chiral profiling of secondary amino acids (AAs) in biological matrices. The sample preparation is carried out directly in aqueous biological sample extracts and involves in situ heptafluorobutyl chloroformate (HFBCF) derivatization-liquid-liquid microextraction of nonpolar products into hexane phase followed by subsequent formation of the corresponding methylamides from the HFB esters by direct treatment with methylamine reagent solution. The (O, N) HFB-butoxycarbonyl-methylamide AA products (HFBOC-MA) are separated on a Chirasil-L-Val capillary column and quantitatively measured by GC-MS operated in selected ion monitoring (SIM) mode.
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