Search results for "Liquid chromatography–mass spectrometry"
showing 10 items of 167 documents
Occurrence of Free and Conjugated Mycotoxins in Aromatic and Medicinal Plants and Dietary Exposure Assessment in the Moroccan Population.
2021
Aromatic and medicinal plants (AMPs), as herbal material, are subjected to contamination by various mycotoxin-producing fungi, either free and conjugated. Such a problem is associated with poor storage practices, and lack of adopting good agricultural practices and good harvesting practices. Nevertheless, AMPs are poorly investigated. The purpose of this study was to investigate the co-occurrence of 15 mycotoxins (four aflatoxins (AFB1, AFB2, AFG1, and AFG2), ochratoxin A (OTA), beauvericin (BEA), four enniatins (ENA, ENA1, ENB, and ENB1), zearalenone (ZEN), alternariol (AOH), tentoxin (TENT), T-2, and HT-2 toxins) in 40 samples of AMPs frequently consumed in Morocco by using liquid chromat…
Multimycotoxin analysis in water and fish plasma by liquid chromatography-tandem mass spectrometry
2015
High performance liquid chromatography-mass spectrometry was used for the determination of 15 mycotoxins in water and fish plasma samples, including aflatoxins, fumonisins, ochratoxin A, sterigmatocistin, fusarenon-X and emerging Fusarium mycotoxins. In this work, dispersive liquid-liquid microextraction (DLLME) was assessed as a sample treatment for the simultaneous extraction of mycotoxins. Results showed differences in recovery assays when different extraction solvents were employed. Ethyl acetate showed better recoveries for the major part of mycotoxins analyzed, except for aflatoxins B2, G1 and G2, which showed better recoveries when employing chloroform as extractant solvent. Fumonisi…
Analysis of perfluorinated compounds in sewage sludge by pressurized solvent extraction followed by liquid chromatography–mass spectrometry
2011
Perfluorinated compounds (PFCs) are widely used in everyday life and one of the main recipients of these compounds is waste water treatment plants (WWTPs). Due to the structure and physicochemical properties of PFCs, these compounds could be redistributed from influent water to sludge. This work reports a new validated protocol for the analysis of 13 perfluorinated acids, 4 perfluorosulfonates and the perfluorooctanesulfonamide. The present work has been focused to develop a sensitive and robust method for the analysis of 18 PFCs in sewage sludge, based on pressurized solvent extraction (PSE) followed by solid phase extraction (SPE) clean-up, analytes separation by liquid chromatography and…
Monitoring of five postharvest fungicides in fruit and vegetables by matrix solid-phase dispersion and liquid chromatography/mass spectrometry
2002
Abstract A method was developed for monitoring dichloran, flutriafol, o-phenylphenol, prochloraz, and tolclofos-methyl in fruits and vegetables, using matrix solid-phase dispersion and liquid chromatography with mass spectrometry detection. The method was used to determine fungicide content in 200 samples of chards, onions, peppers, bananas, lemons, and oranges. Of the samples examined, 54% contained o-phenylphenol with concentrations ranging from 0.005 to 3.34 mg/kg and 35% showed prochloraz in the range of 0.06–1.95 mg/kg. Dichloran, flutriafol, and tolclofos-methyl were detected only occasionally. Only 4% of the samples exceeded the European Union maximum residue limits. The pesticides i…
Assessing drugs of abuse distribution in Turia River based on geographic information system and liquid chromatography mass spectrometry
2017
Drugs of abuse are continuously discharged into wastewaters as part of their elimination process. Pollution at very low concentrations appears to be broad in environmental compartments near populated areas. A total of 42 drugs of abuse and metabolites were analysed in surface water samples collected in 2012 and 2013 by solid phase extraction and liquid chromatography coupled to mass spectrometry. Analytical results of target compounds were georeferenced and integrated into a geographical information systems (GIS). Ecotoxicological risk of drugs of abuse detected in the Turia River was evaluated in this study by calculating risk quotient (RQ). In 2012, 6 compounds were detected in a total of…
Development of pipette tip-based poly(methacrylic acid-co-ethylene glycol dimethacrylate) monolith for the extraction of drugs of abuse from oral flu…
2019
Abstract In this work, a monolithic polymer based on poly(methacrylic acid-co-ethylene glycol dimethacrylate) (MAA-co-EDMA) was prepared inside 200 μL pipette tips for the extraction of drug of abuse from oral fluid samples. After an appropriate surface tip modification, several polymerization mixtures with different monomer/cross-linker ratios, and percentage of porogen were studied. The most appropriate monolith to easily flow organic solvents and oral fluid samples was prepared with a MAA/EDMA ratio of 8:92 wt/wt and dodecanol containing 10 wt% toluene, as porogenic solvent. Parameters affecting the extraction procedure were evaluated and the monolith was characterized in terms of bindin…
Evaluation of beauvericin and enniatins in Italian cereal products and multicereal food by liquid chromatography coupled to triple quadrupole mass sp…
2013
In this study, 48 multicereal baby foods samples including 25 of pasta and 23 of multicereal baby foods from supermarkets of Campania region (Italy) were analysed for evaluating the presence of beauvericin (BEA) and enniatins (ENs) A, A1, B, B1 and B4. Subsequently to evaluate the risk exposure of Italian population and infant population over the consumption of pasta or multicereal baby food, was, respectively, evaluated. For the above mentioned evaluation, a method developed in our laboratory by liquid chromatography tandem mass spectrometry was used. A liquid phase dispersion procedure was optimised for the simultaneous extraction of BEA and the five ENs from multicereal baby food samples…
Versatile, sensitive liquid chromatography mass spectrometry – Implementation of 10 μm OT columns suitable for small molecules, peptides and proteins
2016
AbstractWe have designed a versatile and sensitive liquid chromatographic (LC) system, featuring a monolithic trap column and a very narrow (10 μm ID) fused silica open tubular liquid chromatography (OTLC) separation column functionalized with C18-groups, for separating a wide range of molecules (from small metabolites to intact proteins). Compared to today’s capillary/nanoLC approaches, our system provides significantly enhanced sensitivity (up to several orders) with matching or improved separation efficiency, and highly repeatable chromatographic performance. The chemical properties of the trap column and the analytical column were fine-tuned to obtain practical sample loading capacities…
Nanoparticle Size Is a Critical Physicochemical Determinant of the Human Blood Plasma Corona: A Comprehensive Quantitative Proteomic Analysis
2011
In biological fluids, proteins associate with nanoparticles, leading to a protein "corona" defining the biological identity of the particle. However, a comprehensive knowledge of particle-guided protein fingerprints and their dependence on nanomaterial properties is incomplete. We studied the long-lived ("hard") blood plasma derived corona on monodispersed amorphous silica nanoparticles differing in size (20, 30, and 100 nm). Employing label-free liquid chromatography mass spectrometry, one- and two-dimensional gel electrophoresis, and immunoblotting the composition of the protein corona was analyzed not only qualitatively but also quantitatively. Detected proteins were bioinformatically cl…
Label-free profiling of skeletal muscle using high-definition mass spectrometry
2014
We report automated and time efficient (2 h per sample) profiling of muscle using ultra-performance liquid chromatography (LC) coupled directly with high-definition mass spectrometry (HDMSE). Soluble proteins extracted from rat gastrocnemius (n=10) were digested with trypsin and analysed in duplicate using a 90 min RPLC gradient. Protein identification and label-free quantitation were performed from HDMSE spectra analysed using TransOmics Informatics for Proteomics software. In total 1,514 proteins were identified. Of these, 811 had at least 3 unique peptides and were subsequently used to assess the dynamic range and precision of LC-HDMSE label-free profiling. Proteins analysed by LC-HDMSE …