The Experts below are selected from a list of 2040 Experts worldwide ranked by ideXlab platform
Wolfgang Lindner - One of the best experts on this subject based on the ideXlab platform.
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determination of the metabolites of nitrofuran antibiotics in animal tissue by high performance liquid chromatography tandem mass spectrometry
Journal of Chromatography A, 2001Co-Authors: Alexander Leitner, Peter Zollner, Wolfgang LindnerAbstract:Abstract A LC–MS–MS method is presented to analyse simultaneously the metabolites of four nitrofuran antibacterial agents, Furazolidone, furaltadone, nitrofurazone and nitrofurantoin in animal muscle tissue. Sample clean-up and analyte enrichment was performed by solid-phase extraction (SPE) with a polystyrene sorbent following combined hydrolysis of the protein-bound drug metabolites and derivatisation of the homogenised tissue with 2-nitrobenzaldehyde. Limits of detection of 0.5–5 ng g−1 tissue and limits of determination of 2.5–10 ng g−1 tissue were achieved using electrospray ionisation in positive mode. Analyte identification and quantification was performed according to EU guidelines, using multiple reaction monitoring (MRM) with one precursor ion and two product ions as identifiers. The use of an internal standard in combination with the simplified sample preparation led to a sensitive and reliable analysis method. The yield of the derivatisation reaction was between 66 and 74% and the recovery of SPE reached 92–105% for all values between 10 and 500 ng g−1. The developed analytical protocol has been applied to contaminated tissue samples of Furazolidone- and furaltadone-treated pigs and allowed unequivocal identification and quantification of the metabolites.
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determination of the metabolites of nitrofuran antibiotics in animal tissue by high performance liquid chromatography tandem mass spectrometry
Journal of Chromatography A, 2001Co-Authors: Alexander Leitner, Peter Zollner, Wolfgang LindnerAbstract:Abstract A LC–MS–MS method is presented to analyse simultaneously the metabolites of four nitrofuran antibacterial agents, Furazolidone, furaltadone, nitrofurazone and nitrofurantoin in animal muscle tissue. Sample clean-up and analyte enrichment was performed by solid-phase extraction (SPE) with a polystyrene sorbent following combined hydrolysis of the protein-bound drug metabolites and derivatisation of the homogenised tissue with 2-nitrobenzaldehyde. Limits of detection of 0.5–5 ng g−1 tissue and limits of determination of 2.5–10 ng g−1 tissue were achieved using electrospray ionisation in positive mode. Analyte identification and quantification was performed according to EU guidelines, using multiple reaction monitoring (MRM) with one precursor ion and two product ions as identifiers. The use of an internal standard in combination with the simplified sample preparation led to a sensitive and reliable analysis method. The yield of the derivatisation reaction was between 66 and 74% and the recovery of SPE reached 92–105% for all values between 10 and 500 ng g−1. The developed analytical protocol has been applied to contaminated tissue samples of Furazolidone- and furaltadone-treated pigs and allowed unequivocal identification and quantification of the metabolites.
R J Mccracken - One of the best experts on this subject based on the ideXlab platform.
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determination of Furazolidone in animal feeds using liquid chromatography with uv and thermospray mass spectrometric detection
Journal of Chromatography A, 1997Co-Authors: R J Mccracken, Glenn D KennedyAbstract:Abstract A method is presented for the detection of the nitrofuran antibacterial, Furazolidone in animal feeds. Following solvent extraction of feed samples, the extracts were purified on an alumina column. The column eluents were separated by HPLC using a reversed phase column and detected either by UV monitoring at 365 nm, or by thermospray mass spectrometry, monitoring the ion at m/z 243. The LC-UV procedure was used to quantify Furazolidone at medicated levels (200 mg/kg) and at contamination levels of 5 and 20 mg/kg. The limit of detection was 1 mg/kg. Overall mean recoveries from fortified samples were, 93.4, 98.2 and 98.0% at concentrations of 5, 20 and 200 mg/kg, respectively. The mass spectrometric procedure was used to analyse sample extracts at concentrations
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determination of the Furazolidone metabolite 3 amino 2 oxazolidinone in porcine tissues using liquid chromatography thermospray mass spectrometry and the occurrence of residues in pigs produced in northern ireland
Journal of Chromatography B: Biomedical Sciences and Applications, 1997Co-Authors: R J Mccracken, D G KennedyAbstract:A method is presented for the detection of the Furazolidone metabolite, 3-amino-2-oxazolidinone (AOZ), in porcine tissue. Bound and extractable residues are detected following methanol-water homogenisation, repeated solvent washing and derivatisation with 2-nitrobenzaldehyde. Samples are analysed by using thermospray mass spectrometry-liquid chromatography, monitoring the positive ion m/z 253 with filament-assisted ionisation. There is no interference from tissue matrices or excess 2-nitrobenzaldehyde reagent. The limit of determination for liver and muscle is 10 ng/g. Recoveries are greater than 80%. The assay was used to investigate the occurrence of Furazolidone residues in pigs from Northern Ireland. One hundred samples were analysed. Seventeen of these contained bound AOZ residues. The stability of tissue samples post mortem was investigated in order to achieve optimum storage conditions for samples. When liver was stored at 4 degrees C, the concentration of bound AOZ decreased by 22% within 48 h. However, there were no significant changes in AOZ concentrations in liver that was stored at -20 degrees C for six months.
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determination of Furazolidone in porcine tissue using thermospray liquid chromatography mass spectrometry and a study of the pharmacokinetics and stability of its residues
Analyst, 1995Co-Authors: R J Mccracken, John W Blanchflower, Chris Rowan, Maurice A Mccoy, Glenn D KennedyAbstract:A method is presented for the detection of the nitrofuran, Furazolidone, in porcine tissue. Following methanol–buffer extraction of the tissue, liquid partitioning, and solid-phase clean-up, samples are analysed by using thermospray LC–MS monitoring the positive ion m/z 243 with filament-assisted ionization. The LOD is 1 µg kg–1. The assay is used to investigate the depletion of Furazolidone from tissue and sample stability post mortem. It is necessary to snap-freeze samples by immersion in liquid nitrogen immediately upon collection in order to improve the stability of residues in tissue.
Alexander Leitner - One of the best experts on this subject based on the ideXlab platform.
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determination of the metabolites of nitrofuran antibiotics in animal tissue by high performance liquid chromatography tandem mass spectrometry
Journal of Chromatography A, 2001Co-Authors: Alexander Leitner, Peter Zollner, Wolfgang LindnerAbstract:Abstract A LC–MS–MS method is presented to analyse simultaneously the metabolites of four nitrofuran antibacterial agents, Furazolidone, furaltadone, nitrofurazone and nitrofurantoin in animal muscle tissue. Sample clean-up and analyte enrichment was performed by solid-phase extraction (SPE) with a polystyrene sorbent following combined hydrolysis of the protein-bound drug metabolites and derivatisation of the homogenised tissue with 2-nitrobenzaldehyde. Limits of detection of 0.5–5 ng g−1 tissue and limits of determination of 2.5–10 ng g−1 tissue were achieved using electrospray ionisation in positive mode. Analyte identification and quantification was performed according to EU guidelines, using multiple reaction monitoring (MRM) with one precursor ion and two product ions as identifiers. The use of an internal standard in combination with the simplified sample preparation led to a sensitive and reliable analysis method. The yield of the derivatisation reaction was between 66 and 74% and the recovery of SPE reached 92–105% for all values between 10 and 500 ng g−1. The developed analytical protocol has been applied to contaminated tissue samples of Furazolidone- and furaltadone-treated pigs and allowed unequivocal identification and quantification of the metabolites.
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determination of the metabolites of nitrofuran antibiotics in animal tissue by high performance liquid chromatography tandem mass spectrometry
Journal of Chromatography A, 2001Co-Authors: Alexander Leitner, Peter Zollner, Wolfgang LindnerAbstract:Abstract A LC–MS–MS method is presented to analyse simultaneously the metabolites of four nitrofuran antibacterial agents, Furazolidone, furaltadone, nitrofurazone and nitrofurantoin in animal muscle tissue. Sample clean-up and analyte enrichment was performed by solid-phase extraction (SPE) with a polystyrene sorbent following combined hydrolysis of the protein-bound drug metabolites and derivatisation of the homogenised tissue with 2-nitrobenzaldehyde. Limits of detection of 0.5–5 ng g−1 tissue and limits of determination of 2.5–10 ng g−1 tissue were achieved using electrospray ionisation in positive mode. Analyte identification and quantification was performed according to EU guidelines, using multiple reaction monitoring (MRM) with one precursor ion and two product ions as identifiers. The use of an internal standard in combination with the simplified sample preparation led to a sensitive and reliable analysis method. The yield of the derivatisation reaction was between 66 and 74% and the recovery of SPE reached 92–105% for all values between 10 and 500 ng g−1. The developed analytical protocol has been applied to contaminated tissue samples of Furazolidone- and furaltadone-treated pigs and allowed unequivocal identification and quantification of the metabolites.
Ayfer Yediler - One of the best experts on this subject based on the ideXlab platform.
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determinations of residual Furazolidone and its metabolite 3 amino 2 oxazolidinone aoz in fish feeds by hplc uv and lc ms ms respectively
Journal of Agricultural and Food Chemistry, 2007Co-Authors: Ayfer YedilerAbstract:The antibacterial drug Furazolidone belonging to the group of nitrofuran antibacterial agents has been widely used as an antibacterial and antiprotozoal feed additive for poultry, cattle, and farmed fish in China. During application a large proportion of the administered drug may reach the environment directly or via feces. Although the use of Furazolidone is prohibited in numerous countries, there are indications of its illegal use. It is known that Furazolidone can be rapidly metabolized to 3-amino-2-oxazolidinone (AOZ) in the body of the target organism. In this study, a total of 21 fish feed samples, including 17 commercial fish feeds from local markets in China (representing 15 different formulations) and 4 fish feeds obtained from Germany and Turkey, respectively, are analyzed to determine whether the drug is still illegally used or commercially available feeds are contaminated by this drug. High-performance liquid chromatography (HPLC) and liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) methods have been implemented to determine Furazolidone and its metabolite AOZ in fish feeds containing animal protein, respectively. An efficient and convenient cleanup method for the determination of Furazolidone in fish feeds is developed, and a simple cleanup method for the determination of AOZ is used. Method recoveries for samples used were determined as 87.7-98.3% for Furazolidone at two spike levels of 2.0 and 5.0 ng g(-1) and as 95.6-102.8% for AOZ at spike levels of 0.4 and 0.8 ng g(-1). Limits of detections were 0.4 ng g(-1) for Furazolidone and 0.05 ng g(-1) for AOZ. The established methods are therefore suitable for the determination of Furazolidone and its metabolite AOZ in fish feeds at trace contamination levels. Using the established methods, all fish feed samples have been proved to be Furazolidone negative; however, AOZ is tested in 16 of 17 fish feeds obtained from local markets in the Hubei province of China, with a positive rate as high as 94.1%.
Pascal Mottier - One of the best experts on this subject based on the ideXlab platform.
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analysis of matrix bound nitrofuran residues in worldwide originated honeys by isotope dilution high performance liquid chromatography tandem mass spectrometry
Journal of Agricultural and Food Chemistry, 2004Co-Authors: Seuping Khong, Eric Gremaud, Janique Richoz, Thierry Delatour, Philippe A Guy, Richard H Stadler, Pascal MottierAbstract:A sensitive and selective isotope dilution liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESIMS/MS) method is presented for the simultaneous analysis of the metabolites of four nitrofuran veterinary drugs, that is, Furazolidone, furaltadone, nitrofurantoin, and nitrofurazone, in honey samples. The method entails a combined hydrolysis of protein-bound drug metabolites and derivatization of the resulting metabolites with 2-nitrobenzaldehyde (NBA) during an overnight incubation, followed by a liquid-liquid extraction and a cleanup on a polymeric solid-phase extraction cartridge. Mass spectral acquisition is carried out in the positive ion mode by applying multiple reaction monitoring (MRM) of three diagnostic transition reactions for each analyte under survey. A reliable quantification is obtained by the use of one deuterated analogue per analyte (NBA-d(4) derivative). The method has been validated in honey according to the European Union criteria for the analysis of veterinary drug residues in food. Expressed in underivatized nitrofuran metabolite concentrations, the decision limits (CCalpha) ranged within 0.07-0.46 microg/kg, and the detection capabilities (CCbeta) were within 0.12-0.56 microg/kg. The method has been successfully applied in a survey of honeys of various geographical origins, showing that Furazolidone is the main nitrofuran antibiotic administered to treat bacterial diseases of bees.
