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Quero S.,Fundacio Institute DInvestigacio Germans Trias i Pujol | Quero S.,Autonomous University of Barcelona | Garcia-Nunez M.,Fundacio Institute DInvestigacio Germans Trias i Pujol | Garcia-Nunez M.,Autonomous University of Barcelona | And 15 more authors.
Future Microbiology | Year: 2016

Aim: To compare the discriminatory power of pulsed-field gel electrophoresis (PFGE) and sequence-based typing (SBT) in Legionella outbreaks for determining the infection source. Materials & methods: Twenty-five investigations of Legionnaires' disease were analyzed by PFGE, SBT and Dresden monoclonal antibody. Results: The results suggested that monoclonal antibody could reduce the number of Legionella isolates to be characterized by molecular methods. The epidemiological concordance PFGE-SBT was 100%, while the molecular concordance was 64%. Adjusted Wallace index (AW) showed that PFGE has better discriminatory power than SBT (AWSBT→PFGE = 0.767; AWPFGE→SBT = 1). The discrepancies appeared mostly in sequence type (ST) 1, a worldwide distributed ST for which PFGE discriminated different profiles. Conclusion: SBT discriminatory power was not sufficient verifying the infection source, especially in worldwide distributed STs, which were classified into different PFGE patterns. © 2016 Future Medicine Ltd.

Rubies A.,Laboratori Of Lagencia Of Salut Publica Of Barcelona | Rubies A.,CIBER ISCIII | Antkowiak S.,University of Strathclyde | Granados M.,University of Barcelona | And 3 more authors.
Food Chemistry | Year: 2015

We present a simple method for extracting avermectines from meat, based on a QuEChERS approach followed by liquid chromatography (LC) coupled to triple quadrupole (QqQ) tandem mass spectrometry (MS/MS). The compounds considered are ivermectin, abamectin, emamectin, eprinomectin, doramectin and moxidectin. The new method has been fully validated according to the requirements of European Decision 657/2002/CE (EU, 2002). The method is suitable for the analysis of avermectins at concentration as low as 2.5 μg kg-1, and allows high sample throughput. In addition, the detection of avermectins by high resolution mass spectrometry using a quadrupole-Orbritrap (Q-Orbitrap) hybrid instrument has been explored, and the target Selected Ion Monitoring data dependent MS/MS (t-SIM-dd MS/MS) mode has been found to provide excellent performance for residue determination of target analytes. © 2015 Elsevier Ltd. All rights reserved.

Rubies A.,Laboratori Of Lagencia Of Salut Publica Of Barcelona | Guo L.,Laboratori Of Lagencia Of Salut Publica Of Barcelona | Guo L.,University of Barcelona | Centrich F.,Laboratori Of Lagencia Of Salut Publica Of Barcelona | And 2 more authors.
Analytical and Bioanalytical Chemistry | Year: 2016

We developed a Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) method for the high throughput determination of 10 non-steroidal anti-inflammatory drugs (NSAIDs) in milk samples using high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) with a triple quadrupole (QqQ) instrument and an electrospray ionization (ESI) source. The new extraction procedure is highly efficient, and we obtained absolute recoveries in the range 78.1–97.1 % for the extraction and clean-up steps. Chromatographic separation is performed in the gradient mode with a biphenyl column and acidic mobile phases consisting of water and acetonitrile containing formic acid. The chromatographic run time was about 12 min, and NSAID peaks showed a good symmetry factor. For MS/MS detection, we used multiple reaction monitoring (MRM) mode, using ESI in both positive and negative modes. Our method has been validated in compliance with the European Commission Decision 657/2002/EC, and we obtained very satisfactory results in inter-laboratory testing. Furthermore, we explored the use of a hybrid high resolution mass spectrometer, combining a quadrupole and an Orbitrap mass analyzer, for high resolution (HR) MS/MS detection of NSAIDs. We achieved lower NSAID quantification limits with Q-Orbitrap high resolution mass spectrometry (HRMS/MS) detection than those achieved with the QqQ instrument; however, its main feature is its very high selectivity, which makes HRMS/MS particularly suitable for confirmatory analysis. © 2016 Springer-Verlag Berlin Heidelberg

Rubies A.,Laboratori Of Lagencia Of Salut Publica Of Barcelona | Rubies A.,CIBER ISCIII | Munoz E.,Laboratori Of Lagencia Of Salut Publica Of Barcelona | Munoz E.,CIBER ISCIII | And 7 more authors.
Journal of Chromatography A | Year: 2015

A new method for the analysis of lipophilic marine biotoxins (okadaic acid, dinophysistoxins, azaspiracids, pectenotoxins, yessotoxins, spirolids) in fresh and canned bivalves has been developed. A QuEChERS methodology is applied; i.e. the analytes are extracted with acetonitrile and clean-up of the extracts is performed by dispersive solid phase extraction with C18. The extracts are analyzed by ultra-high performance liquid chromatography coupled to a hybrid quadrupole-Orbitrap mass spectrometer, operating in tandem mass spectrometry mode, with resolution set at 70,000 (m/z 200, FWHM). Separation of the analytes, which takes about 10min, is carried out in gradient elution mode with a BEH C18 column and mobile phases based on 6.7mM ammonia aqueous solution and acetonitrile mixtures. For each analyte the molecular ion and 1 or 2 product ions are acquired, with a mass accuracy better than 5ppm. The quantification is performed using surrogate matrix matched standards, with eprinomectin as internal standard. The high-throughput method, which has been successfully validated, fulfills the requirements of European Union legislation, and has been implemented as a routine method in a public health laboratory. © 2015 Elsevier B.V.

Munoz E.,Laboratori Of Lagencia Of Salut Publica Of Barcelona | Munoz G.,Laboratori Of Lagencia Of Salut Publica Of Barcelona | Pineda L.,Laboratori Of Lagencia Of Salut Publica Of Barcelona | Serrahima E.,Laboratori Of Lagencia Of Salut Publica Of Barcelona | Centrich F.,Laboratori Of Lagencia Of Salut Publica Of Barcelona
Journal of AOAC International | Year: 2012

A multiresidue method based on GC or LC and MS or MS/MS for the determination of 204 pesticides in diverse food matrixes of animal and plant origin is described. The method can include different stages of cleanup according to the chemical characteristics of each sample. Samples were extracted using accelerated solvent extraction. Those with a high fat content or that contained chlorophyll required further purification by gel permeation chromatography and/or SPE (ENVI-Carb). The methodology developed here was fully validated; the LOQs for the 204 pesticides are presented. The LOQ values lie between 0.01 to 0.02 mg/kg. However, in some cases, mainly in baby food, they were as low as 0.003 mg/kg, thereby meeting European Union requirements on maximum residue levels for pesticides, as outlined in European regulation 396/2005 and the Commission Directive 2003/13/EC. The procedure has been accredited for a wide scope of pesticides and matrixes by the Spanish Accreditation Body (ENAC) following ISO/IEC 17025:2005, as outlined in ENAC technical note NT-19.

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