Search results for "flame"
showing 10 items of 108 documents
Evaluation of analytical performance of gas chromatography coupled with atmospheric pressure chemical ionization Fourier transform ion cyclotron reso…
2019
Abstract A new analytical method was established and validated for the analysis of eighteen halogenated flame retardants (HFRs)in food products. Gas chromatography (GC) coupled to Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) employing atmospheric pressure chemical ionization (APCI) was used for the identification and quantitation of contaminants. Intra-laboratory validation of the method was performed with respect to recovery, repeatability, linear calibration ranges, instrumental and method limits of quantitation (i-LOQ and m-LOQ), and trueness was verified where possible by analysis of reference materials (RMs). The validation results indicated recoveries of ana…
Multi-analyte method for the analysis of legacy and alternative brominated and chlorinated flame retardants in food products of animal origin using g…
2019
Abstract An analytical method was developed and validated for the analysis of 32 halogenated flame retardants (HFRs), including 13 polybrominated diphenyl ethers (PBDEs), 9 dechlorane-related compounds (DRCs) and 10 of the so-called alternative BFRs in food samples of animal origin. Gas chromatography (GC) coupled with magnetic sector high resolution mass spectrometry (HRMS) was used for the instrumental analysis. Intralaboratory validation of the developed method was performed in terms of recovery, repeatability, linear calibration ranges, instrumental and method limits of quantitation (i-LOQ and m-LOQ). Where possible, trueness was verified by the analysis of reference materials (RMs). Fo…
Rayuela de visiones imaginarias del flamenco
2008
El imaginario colectivo no sólo ha incidido en el arte y en el espectador sino que también se ha transformado en el tiempo. Desde la literatura, intelectuales, compositores, investigadores, artistas plásticos hasta las nuevas tecnologías, han construido una complejidad de sustratos que permanecen con diferente intensidad y que configuran el calidoscopio de la visión artística. En estas líneas nos aproximamos a distintas visiones sobre el flamenco, la crítica social de la generación del 98; al lado más humano del romanticismo de Glinka; a los nuevos ingenios: “fonoarqueología” y primeras imágenes fotográficas del flamenco, centrándonos en los procesos técnicos y químicos; el mundo de la inve…
Emerging brominated flame retardants and dechlorane-related compounds in European eels (Anguilla anguilla) from Latvian lakes
2017
Abstract Fifteen halogenated flame retardants (HFRs) including seven emerging brominated flame retardants (EBFRs) and eight dechlorane-related compounds (DRCs) were analyzed in eels (Anguilla anguilla) sampled from five Latvian lakes. Out of the seven EBFRs, hexabromocyclododecane (HBCD) and decabromodiphenyl ethane (DBDPE) were found in eels in quantifiable concentrations, up to 6.58 and 33.0 ng g−1 lipid weight (l.w.), respectively. The mean total concentration of DRCs (∑DRC) in the samples was 0.62 ng g−1 l.w. and the geographical distribution of DRC contamination was nearly uniform among the selected lakes. Dechlorane 602 (Dec 602) was the predominant component, whereas the composition …
Preparation of photocatalysts by physical methodologies
2021
The synthesis of photocatalytic materials is an important task for obtaining better results in terms of activity and/or selectivity in photocatalysis. This chapter reports an overview of the main methodologies using physical techniques to obtain bulky, supported powders or films and coatings to be used as heterogeneous photocatalysts. The classical chemical methodologies for the preparation of photocatalytic materials are presented in the previous chapter, so the information presented here complements the aforementioned one. Materials scientists and engineers have made significant progresses in the improvement of methods of synthesis of nanomaterial solids by developing different apparatuse…
"Haters gonna hate": characterizing hater comments on YouTube thanks to impoliteness theories
2017
International audience; Previous studies have shown that comments on YouTube tend to show a “low degree of neutral stance” (Sindoni, 2014: 203). Comments are often either strongly positive or negative. Negative comments themselves commonly display all forms of aggressive and impolite behaviour (sarcasm, name-calling, hostility, ad personam attacks and a whole variety of other deliberate face-threatening acts). The epitome of this behaviour is the so-called “hater”, a commenter that deliberately posts abusive comments (“you suck”, “”Miranda sings is shit”, “fuck you Miranda sings”), generally unconnected to the content of the video and/or not constructive (see definitions in Lange: 2007). Ev…
La calle y el espacio público en la pintura gótica hispana
2001
En los siglos finales de la Edad Media los pintores comenzaron a utilizar su propio entorno como fuente de inspiración para ambientar la historia sagrada. En concreto en la Península Ibérica se han conservado algunas obras en cuyo fondo se reproducen, con mayor o menor fidelidad, calles y plazas de aspecto claramente medieval. El objeto del presente artículo es analizar esas vistas en su doble vertiente: como encuadramiento de las escenas y como elementos de la realidad, observando los modelos que se seguían resaltando la validez de estas fuentes iconográficas para el estudio de la vida cotidiana en el pasado.
Quantification of poisons for Ziegler Natta catalysts and effects on the production of polypropylene by gas chromatographic with simultaneous detecti…
2020
[EN] This article describes a new simultaneous method for the analysis of sulfur-type poisons, hydrocarbons and permanent gases affecting the productivity of the Ziegler Natta catalyst during the synthesis of polypropylene on an industrial scale in a fluidized-bed reactor. The identification was achieved employing a configuration of the seven-valve chromatographic system, with events at different times, allowing distribution of the sample through multiple columns, and finally reaching the helium ionization detectors of pulsed discharge, flame ionization and mass spectrometry. The results obtained show a good precision of the method used because the variability was less than 1.02% in area an…
Stability of Plant Sterols in Ingredients Used in Functional Foods
2011
The content of plant sterol (PS) and their oxidation products (POPs) in eight ingredients used to enrich functional foods was studied. A gas chromatographic (GC) technique with mass-spectrometric detection was used for identification, while GC with a flame ionization detector (GC-FID) was used for quantification. β-Sitosterol was the most abundant phytosterol, and the main POPs found were derived from this compound (7α/β-hydroxysitosterol, 7-ketositosterol, and sitostanetriol). The total amount of POPs found in the ingredients ranged from 29.03 to 110.02 μg/100 g PS. The β-sitosterol oxidation rates ranged from 10 to 50 μg β-sitosterol oxides/100 g of β-sitosterol. In view of this low rate …
Analysis of eicosapentaenoic and docosahexaenoic acid geometrical isomers formed during fish oil deodorization.
2006
International audience; Addition of long-chain polyunsaturated fatty acids (LC-PUFAs) from marine oil into food products implies preliminary refining procedures of the oil which thermal process affects the integrity of LC-PUFAs. Deodorization, the major step involving high temperatures, is a common process used for the refining of edible fats and oils. The present study evaluates the effect of deodorization temperature on the formation of LC-PUFA geometrical isomers. Chemically isomerized eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were used as reference samples. Fish oil samples have been deodorized at 180, 220 and 250 °C for 3 h and pure EPA and DHA fatty acid methyl esters…