The Experts below are selected from a list of 360 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.
Kate M Barry - One of the best experts on this subject based on the ideXlab platform.
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comparison of dairy phospholipid preparative extraction Protocols in combination with analysis by high performance liquid chromatography coupled to a charged aerosol detector
International Dairy Journal, 2016Co-Authors: Kate M Barry, T G Dinan, Brian A Murray, Philip M KellyAbstract:Abstract Different fat extraction methodologies, Rose Gottlieb (RG), Folch with CaCl 2 (F1) and Folch without CaCl 2 (F2) were evaluated alongside a high performance liquid chromatography (HPLC)-based Analytical Protocol involving a charged aerosol detector (CAD) to optimise the separation and quantification of dairy phospholipids (PLs). Total PL recovery by F2 proved to be 1.8- and 2.5-fold greater than RG and F1, respectively. Alteration of the HPLC elution program maximised peak separation and reduced co-elution of individual PLs detected by CAD. Two-fold reduction in retention time variability was achieved,
Honghai Wang - One of the best experts on this subject based on the ideXlab platform.
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development of an on line matrix solid phase dispersion fast liquid chromatography tandem mass spectrometry system for the rapid and simultaneous determination of 13 sulfonamides in grass carp tissues
Journal of Chromatography A, 2011Co-Authors: Yanbin Lu, Qing Shen, Hong Zhang, Honghai WangAbstract:Abstract A novel Analytical Protocol based on interfacing on-line matrix solid-phase dispersion (MSPD) with high-performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS) was developed for extraction and determination of 13 sulfonamide residues in grass carp tissues. The target analytes were separated on a fused-core C18-silica column with a period of 7 min and quantified by a triple–quadrupole linear ion-trap mass spectrometer in positive ion multiple-reaction monitoring (MRM) mode. The proposed method was optimized and validated according to Commission Decision 2002/657/EC. The matrix-matched calibration curves were performed at six concentration levels and good linear relationship (R2 = 0.993–0.998) was observed within the range of 0.1–100 ng mL−1. The mean values of relative standard deviation of intra- and inter-day ranging from 1.8% to 7.8% and from 2.8% to 10.3% were obtained, respectively. Moreover, satisfied recoveries (69.0–96.3%) of all studied sulfonamides were demonstrated in different spiked levels, with RSDs ≤ 13.2%. The proposed method has been applied successfully to the analysis of sulfonamides in several grass carp samples, and the results indicated that this novel instrumental coupling was fast, sensitive, reliable and environmental friendly with good prospects.
E Castellucci - One of the best experts on this subject based on the ideXlab platform.
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analysis of natural and artificial ultramarine blue pigments using laser induced breakdown and pulsed raman spectroscopy statistical analysis and light microscopy
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2009Co-Authors: Iacopo Osticioli, N F C Mendes, Austin Nevin, Maurizio Becucci, E CastellucciAbstract:Abstract Pulsed laser induced breakdown spectroscopy (LIBS) and Raman spectroscopy were performed using a novel laboratory setup employing the same Nd:YAG laser emission at 532 nm for the analysis of five commercially available pigments collectively known as “ultramarine blue”, a sodium silicate material of either mineral origin or an artificially produced glass. LIBS and Raman spectroscopy have provided information regarding the elemental and molecular composition of the samples; additionally, an Analytical Protocol for the differentiation between natural (lapis lazuli) and artificial ultramarine blue pigments is proposed. In particular LIBS analysis has allowed the discrimination between pigments on the basis of peaks ascribed to calcium. The presence of calcite in the natural blue pigments has been confirmed following Raman spectroscopy in specific areas of the samples, and micro-Raman and optical microscopy have further corroborated the presence of calcite inclusions in the samples of natural origin. Finally multivariate analysis of Laser induced breakdown spectra using principal component analysis (PCA) further enhanced the differentiation between natural and artificial ultramarine blue pigments.
Maria Careri - One of the best experts on this subject based on the ideXlab platform.
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investigation of different sample pre treatment routes for liquid chromatography tandem mass spectrometry detection of caseins and ovalbumin in fortified red wine
Food Control, 2014Co-Authors: Monica Mattarozzi, Marco Milioli, Chiara Bignardi, Lisa Elviri, Claudio Corradini, Maria CareriAbstract:Different sample treatment Protocols for the liquid chromatography–electrospray-tandem mass spectrometry (LC–ESI-MS/MS) analysis of potential residuals of ovalbumin and caseins added to red wines were developed. In particular, attention was paid to the simultaneous detection and quantitation of fining agent residues, i.e. ovalbumin, α- and β-casein, in wine samples. The different sample treatment methods were compared in terms of protein recovery. The use of denaturing agents combined with size exclusion concentration and purification allowed to obtain a reproducible (RDS < 20%) Analytical Protocol with good recoveries (73(±2) – 109(±4)% range) for digested proteins from 12.5 mL of wine sample. Matrix-matched calibration from LC–ESI-MS/MS analysis indicated that the devised method allowed detection of target peptides in the 0.01–0.8 μg/mL range. Finally, method applicability and selectivity was demonstrated by using fining agents commonly exploited in winery industry and by analyzing 20 commercial red wine samples.