Search results for "Ultra high performance"
showing 7 items of 7 documents
Effect of Sunlight Exposure on Anthocyanin and Non-Anthocyanin Phenolic Levels in Pomegranate Juices by High Resolution Mass Spectrometry Approach
2020
Quali-quantitative analyses of anthocyanins and non-anthocyanin phenolic compounds performed with the use of liquid chromatography coupled with high resolution mass spectrometry, were evaluated in juice of pomegranate fruits (&lsquo
Wide-range screening of banned veterinary drugs in urine by ultra high liquid chromatography coupled to high-resolution mass spectrometry
2012
In this work, an ultra high performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS) methodology is proposed for the multi-class multi-residue screening of banned and unauthorized veterinary drugs in bovine urine, using an Orbitrap Exactive™ analyzer working at a resolving power of 50,000 FWHM in full scan, both in positive and negative mode. The method currently covers 87 analytes belonging to different families such as steroid hormones, β-agonists, resorcylic acid lactones (RAL), stilbens, tranquillizers, nitroimidazoles, corticosteroids, NSAIDs, amphenicoles, thyreostatics and other substances such as dapsone. A database including the elemental composition, the po…
Ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry to identify contaminants in water: an insight on environment…
2013
Ultra-high pressure liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-QqTOF-MS) acquiring full scan MS data for quantification, and automatic data dependent information product ion spectra (IDA-MS/MS) without any predefinition of the ions by the user was checked for identifying organic contaminants in water samples. The use of a database with more than 2000 compounds achieved high confidence results for a wide number of contaminants based upon retention time, accurate mass, isotopic pattern and MS/MS library searching. More than 20 contaminants, mostly pharmaceuticals, but also mycotoxins and polyphenols were unambiguously identified. Furthermore, the combination of s…
Determining the Environmental Benefits of Ultra High Performance Concrete as a Bridge Construction Material
2017
Ultra High Performance Concrete (UHPC) is a material that is attracting attention in the construction industry due to the high mechanical strength and durability, leading to structures having low maintenance requirements. The production of UHPC, however, has generally higher environmental impact than normal strength concrete due to the increased demand of cement required in the concrete mix. What is still not sufficiently investigated, is if the longer lifetime, slimmer construction and lower maintenance requirements lead to a net environmental benefit compared to standard concrete bridge design. This study utilizes life cycle assessment (LCA) to determine the lifetime impacts of two compar…
The influence of steel fibres on compressive and tensile strength of ultra high performance concrete : A review
2020
Abstract This review paper presents the effects of steel fibre reinforcement regarding the compressive and tensile strength of UHPC. The intention is to give an overview of the research field and supply guidance for future research. Relevant papers were identified through a systematic literature search. An accumulation of the results shows that fibres have potential for improving the tensile strength of UHPC. The effect depends on fibre content, type and hybrid combinations. The effect of fibres on compressive strength seems to be questionable. Variations in test specimen geometry and other factors might also influence the results.
Fast analysis of polyphenols and alkaloids in cocoa-based products by ultra-high performance liquid chromatography and Orbitrap high resolution mass …
2018
The cocoa varieties Criollo, Forastero and Trinitario, which have different organoleptic properties, quite often are mixed together in cocoa-based products. The objective of this work was to develop a rapid method for the simultaneous determination of polyphenols (n = 35) and alkaloids (n = 2) in cocoa-based products by using the high throughput advantages provided by the Q Exactive Hybrid Quadrupole-Orbitrap Mass Spectrometer (FIRMS). The proposed procedure was optimized and validated in terms of selectivity and specificity (mass accuracy 0.990), accuracy (recovery range from 89.1 to 112.4%) and precision (relative standard deviation < 10%). The method was applied to 80 cocoa-based samples…
Analysis of β2-agonists in cattle hair samples using a rapid UHPLC–ESI–MS/MS method
2016
A simple and efficient method was developed for simultaneous analysis of five illegal residual β2-agonists in cattle hair. β2-Agonists were quantified by ultra high performance liquid chromatography coupled with electrospray ionisation tandem mass spectrometry operating in positive multiple-reaction monitoring mode. The method was validated as quantitative confirmatory method according to the EU Decision 2002/657/EC: instrumental linearity, specificity, precision, recovery, decision limit (CCα) and detection capability (CCβ) were evaluated. The recovery were greater than 90% and the method appeared suitable for the control of these β2-agonists in cattle hair samples with LOQ values between …