Enginyeria Química i Química Analítica: Enviaments recents
Ara mostrant els elements 141-160 de 790
Assessment of experimental factors affecting the sensitivity and selectivity of the spectrophotometric estimation of proanthocyanidins in foods and nutraceuticals
The assessment of a reliable method for the determination of active proanthocyanidins (PACs) in functional foods, nutraceuticals, and foodstuffs is still a pending analytical challenge. In general, pharmaceutical and food ...
El residu: paràbola de la maionesa i l'allioli
...I posant-se enmig dels seus deixebles, els va proposar aquesta paràbola: El regne dels homes és semblant a un jove príncep que heretà un palau i, per celebrar-ho, preparà un gran banquet per a tots els seus amics. Disposà ...
Reverse osmosis concentrate treatment by chemical oxidation and moving bed biofilm processes
In the present work, four oxidation techniques were investigated (O3, O3/UV, H2O2/O3, O3/H2O2/UV) to pre-treat reverse osmosis (RO) concentrate before treatment in a moving-bed biofilm reactor (MBBR) system. Without previous ...
Authentication of Cocoa Products Based on Profiling and Fingerprinting Approaches: Assessment of Geographical, Varietal, Agricultural and Processing Features
Cocoa and its derivative products, especially chocolate, are highly appreciated by consumers for their exceptional organoleptic qualities, thus being often considered delicacies. They are also regarded as superfoods due ...
Field-Amplified Sample Injection-Micellar Electrokinetic Chromatography for the Determination of Benzophenones in Food Simulants
A field-amplified sample injection-micellar electrokinetic chromatography (FASI-MEKC) method for the determination of 14 benzophenones (BPs) in a food simulant used in migration studies of food packaging materials was ...
Ammoniacal nitrogen recovery from swine slurry using a gas-permeable membrane: pH control strategies and feed-to-trapping volume ratio
Gas-permeable membrane (GPM) technology is gaining interest to recover nitrogen from residual effluents due to its effectiveness, simple operation and capacity of producing a nutrient rich product with fertilising value. ...
Mercury films on commercial carbon screen-printed devices for the analysis of heavy metal ions: a critical evaluation
The suitability of mercury films on commercial screen-printed electrodes for the analysis of heavy metal ions is critically tested for the particular case of Pb(II)-ions. Although determination is possible by anodic stripping ...
LINEAR UNMIXING PROTOCOL FOR HYPERSPECTRAL IMAGE FUSION ANALYSIS APPLIED TO A CASE STUDY OF VEGETAL TISSUES
Hyperspectral imaging (HSI) is a useful non-invasive technique that offers spatial and chemical information of samples. Often, different HSI techniques are used to obtain complementary information from the sample by combining ...
Aula invertida utilizando dispositivos móviles para mejorar el aprendizaje de espectrometría de masas en estudiantes del Máster Universitario en Química Analítica de la Universidad de Barcelona
Una estrategia de aprendizaje activo basada en aula invertida utilizando dispositivos móviles ha sido desarrollada como actividad de evaluación continua para mejorar la adquisición de conocimientos en espectrometría de ...
Estimation of the octanol-water distribution coefficient of acidic compounds by microemulsion electrokinetic chromatography
The feasibility of extending the determination of the lipophilicity of partially ionized acids (log Do/w) by microemulsion electrokinetic chromatography (MEEKC) is tested. Theoretical considerations predict that a linear ...
Porphyrin binding mechanism is altered by protonation at the loops in G-quadruplex DNA formed near the transcriptional activation site of the human c-kit gene
Background G-quadruplex DNA structures are hypothesized to be involved in the regulation of gene expression and telomere homeostasis. The development of small molecules that modulate the stability of G-quadruplex structures ...
Rheological behavior of hydrophobically modified hydroxyethyl cellulose solutions: A linear viscoelastic model
The rheological behavior of hydrophobically modified hydroxyethyl cellulose HMHEC, an associative thickener, was studied and compared with that of hydrophobically modified ethoxylated urethanes HEURs and nonassociative ...
Effects of inorganic nitrogen (NH4Cl) and biodegradable organic carbon (CH3COONa) additions on a pilot-scale seawater biofilter
Biofilters degrade only a small fraction of the natural organic matter (NOM) contained in seawater which is the leading cause of biofouling in downstream processes. This work studies the effects of chemical additions on ...
Simplified screening approach of anabolic steroid esters using a compact atmospheric solid analysis probe mass spectrometric system
Due to the absence of chromatographic separation, ambient ionization mass spectrometry had the potential to improve the throughput of control laboratories in the last decades and will soon be an excellent approach for ...
Liquid-phase synthesis of butyl levulinate with simultaneous water removal catalyzed by ion exchange resins
The liquid-phase synthesis of butyl levulinate by esterification of levulinic with an excess of 1-butanol (initial molar ratio 1:3) and simultaneous water removal has been studied at atmospheric pressure and at the boiling ...
Development and validation of an enzyme linked immunsorbent assay for fluoriquinolones in animal feeds
An enzyme-linked immunosorbent assay (ELISA) for analysis of fluoroquinolones residues in animal feeds has been developed and validated according to Commission Decision 2002/657/EC criteria. Initially, direct and indirect ...
Mercury (II) and methylmercury determination in waters by liquid chromatography hyphenated to cold vapour atomic fluorescence spectrometry after online short-column preconcentration
This paper reports a method developed for the simultaneous determination of methylmercury (MeHg+) and mercury(II) (Hg2+) species in water by liquid chromatography coupled to online UV irradiation and cold vapour atomic ...
Optimization of the One-Pot Synthesis of Butyl Levulinate from Fructose and 1-Butanol
The one-pot synthesis of butyl levulinate from fructose and 1- butanol has been optimized using the ion-exchange resin Dowex 50Wx2 as a catalyst in a batch reactor. The effects of temperature (120−150 °C), initial quantity ...
Hierarchical meso-mesoporous and macro-mesoporous silica templated by mixtures of polyoxyethylene fluoroalkyl ether and triblock copolymer
We report here the synthesis of different kinds of hierarchical porous silica materials by using mixtures of an amphiphilic block copolymer (Pluronic P123) and a nonionic fluorinated surfactant. In particular, we have taken ...
Identification of metabolites and thermal transformation products of quinolones in raw cow milk by liquid chromatography coupled to high resolution mass spectrometry.
The presence of residues of antibiotics, metabolites, and thermal transformation products (TPs), produced during thermal treatment to eliminate pathogenic microorganisms in milk, could represent a risk for people. Cow"s ...
