In all EU member states, the use in livestock farming of certain substances having a hormonal action is prohibited. Clenbuterol, the beta-adrenergic agonist, has some growth promoting characteristics. Screening for clenbuterol can be carried out by an immunoassay. Gas chromatography-mass spectrometry (GC-MS) is very valuable for confirmatory purposes. In full scan MS it is impossible to fulfil the EU criteria of four diagnostic ions with one single ionisation mode. Some alternative possibilities are: (1) the use of two different ionisation modes, (2) the use of different derivatization methods or (3) the use of tandem MS. Each derivatisation or ionisation mode on its own did not give a sufficient number of ions. By combining these different possibilities we were able to obtain four ions, fulfilling the EU criteria.
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http://dx.doi.org/10.1016/0021-9673(96)00465-7 | DOI Listing |
RSC Adv
January 2025
Department of Chemistry, School of Science, GITAM Deemed to be University Hyderabad-502329 India
The current research presents novel LC-TQ-MS/MS and cost-effective UPLC methods intended for the accurate quantification of mefenamic acid-N-nitroso drug substance-related impurity-NDSRI (N-MFA) in mefenamic acid (MFA) tablet and pediatric suspension dosage forms. The acceptable intake of N-MFA is derived from the TD50 (Median Toxic Dose-50%) value of N-nitroso diphenylamine. The analytical separation was achieved for the UPLC method using an XBridge BEH Shield RP18 Column (150 × 3.
View Article and Find Full Text PDFJ Chromatogr B Analyt Technol Biomed Life Sci
January 2025
Department of Chemistry, Cleveland State University, Cleveland, OH 44115, USA. Electronic address:
The integrated stress response (ISR) is a cellular defense mechanism activated under stress conditions. When the ISR is activated, it slows the production of proteins, the building blocks that cells need to function. Trans-integrated stress response inhibitor (trans-ISRIB) is a compound that can reverse the effects of ISR activation, showing promise for treating neurodegenerative diseases.
View Article and Find Full Text PDFFront Pharmacol
January 2025
Department of Pharmacy, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China.
Background: Ripretinib, a broad-spectrum tyrosine kinase inhibitor, has been approved for the treatment of advanced gastrointestinal stromal tumors in adult patients. Clinical studies have shown that higher exposure of ripretinib correlates with improved efficacy, highlighting the potential clinical significance of therapeutic drug monitoring. In this study, a simple and stable liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was attempted to be established and validated for pharmacokinetic studies of ripretinib and its metabolite DP-5439 and therapeutic drug monitoring in human plasma.
View Article and Find Full Text PDFACS Omega
January 2025
Clinical Nuclear Medicine Center, Imaging Clinical Medical Center, Institute of Nuclear Medicine, Institute of Clinical Mass Spectrometry Applied Research Center, Department of Nuclear Medicine, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai 200072, China.
Water-soluble vitamins play essential roles in normal body functions and metabolic activities. However, few methods have simultaneously measured all nine water-soluble vitamins in biological matrices. In this study, we developed a sensitive and accurate method for the simultaneous measurement of thiamine (B1), riboflavin (B2), nicotinamide (B3), pantothenic acid (B5), 4-pyridoxic acid (B6), biotin (B7), 5-methyltetrahydrofolic acid (B9), ascorbic acid (VC), and methylmalonic acid (MMA) in human serum.
View Article and Find Full Text PDFAnal Chem
January 2025
Leibniz-Institut für Analytische Wissenschaften-ISAS-e.V., Bunsen-Kirchhoff-Straße 11, D-44139 Dortmund, Germany.
The identification of polar and neutral lipid species as biomarkers in complex biological samples is a key task in clinical and life sciences. Electrospray and plasma-based ionization techniques are necessary to cover the full range of lipidomes, owing to their limited molecular polarity ranges. However, combining both to generate hybrid spectra is difficult without averaging spectra, as electrospray and plasma sources operate under vastly different conditions.
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