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5-Nitro-2-furaldehyde is proposed as a new derivatizing agent for determining four nitrofuran metabolites: 3-amino-2-oxazolidinone, 3-amino-5-methylmorpholino-2-oxazolidinone, 1-aminohydantoin, and semicarbazide in chicken eggs by HPLC with tandem mass spectrometric detection. The derivatization products were identified; they are the initial nitrofurans: furazolidone, furaltadone, nitrofurantoin, and nitrofurazone, respectively. Sample preparation includes acid hydrolysis, derivatization, fat removal by hexane extraction, and the further purification of the extracts on cartridges packed with Diapak P-3 hypercrosslinked polystyrene. The method ensures the quantitative isolation of metabolites (recovery rates are 95 to 106%) and good reproducibility (RSD [less than or equal to] 13%)., Author(s): A. O. Melekhin [sup.1] [sup.2], V. V. Tolmacheva [sup.1], E. G. Shubina [sup.2], S. G. Dmitrienko [sup.1], V. V. Apyari [sup.1], A. I. Grudev [sup.2], Yu. A. Zolotov [sup.1] [...]

Hypercrosslinked polystyrene is proposed for the multicomponent solid-phase extraction of residues of 63 veterinary preparations from various classes (sulfonamides, tetracyclines, quinolones, amphenicols, nitroimidazoles, [beta]-lactams, macrolides, lincosamides, and pleuromutilins) in their determination in chicken meat by HPLC-tandem mass spectrometry. Sample preparation includes the extraction of analytes with a McIlvaine buffer solution, fat removal by extraction with hexane, and the further purification of the extracts on cartridges with hypercrosslinked polystyrene. The method ensures the quantitative extraction of analytes (recovery rates are from 83 to 117%) and good reproducibility (RSD [less than or equal to] 12%). Veterinary preparations were identified by the exact masses of analyte ions formed in electrospray ionization on switching positive and negative polarity. The matrix effect for all veterinary drugs was below 20%. The determination was carried out by the method of matrix calibration; the limits of detection and determination were 0.01-0.3 and 0.02-1 ng/g, respectively. An analysis of contaminated chicken meat samples showed that the results are in satisfactory agreement with the data obtained by the methods adopted in the Russian Federation for the determination of various groups of antibiotics., Author(s): A. O. Melekhin [sup.1] [sup.2], V. V. Tolmacheva [sup.1], E. G. Shubina [sup.2], S. G. Dmitrienko [sup.1], V. V. Apyari [sup.1], A. I. Grudev [sup.2] Author Affiliations: (1) grid.14476.30, [...]

A quantitative multi-class multi-residue analytical method was developed for the determination of veterinary drugs in milk by high-performance liquid chromatography - tandem mass spectrometry (HPLC-MS/MS). A total of 132 veterinary drugs investigated belonged to almost 15 classes including sulfonamides, β-lactams, tetracyclines, quinolones, macrolides, nitrofurans, nitroimidazoles, phenicols, lincosamides, pleuromutilins, macrocyclic lactones, quinoxaline antibiotics, benzimidazoles, anthelmintics, coccidiostats and some others. A magnetic solid-phase extraction procedure was developed using magnetic hypercrosslinked polystyrene (HCP/Fe 3 O 4 ) for the sample preparation prior to HPLC-MS/MS without deproteinization step. The results indicated recoveries of 85-107% for 14 sulfonamides, 85-120% for 13 β-lactams, 89-115% for 4 tetracyclines, 82-119% for 14 quinolones, 82-115% for 8 macrolides, 97-109% for 4 nitrofurans, 84-115% for 10 nitroimidazoles, 89-114% for 3 phenicols, 86-111% for 3 lincosamides, 97-102% for 2 pleuromutilins, 72-88% for 4 macrocyclic lactones, 87-104% for 4 quinoxaline antibiotics, 76-119% for 21 benzimidazoles, 79-115% for 12 anthelmintics, 81-118% for 12 coccidiostats and 75-119 % for 5 unclassified drugs, with relative standard deviations (RSDs) of less than 20%, and the LOQs ranged from 0.05 to 1 μg kg -1 . This methodology was then applied to field-collected real milk samples and trace levels of some veterinary drugs were detected., (Copyright © 2022 Elsevier Ltd. All rights reserved.)