Browsing Química by Title
Now showing items 85-104 of 313
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Dealing with long‐range interactions in the determination of polyelectrolyte ionization properties. Extension of the transfer matrix formalism to the full range of ionic strengths
(Wiley, 2016-11-14)The ionization state of charged macromolecules in solution is usually determined by the extent of the binding processes. These processes are very sensitive to the ionic strength of the medium, which are of long-range nature. ... -
Detection of silver nanoparticles in seawater at ppb levels using UV-visible spectrophotometry with long path cells
(Elsevier, 2017-03-01)Silver nanoparticles (AgNPs) are emerging contaminants that are difficult to detect in natural waters. UV-visible spectrophotometry is a simple technique that allows detection of AgNPs through analysis of their characteristic ... -
Determinación rápida del contenido en cromo en licores y baños de curtición
(Asociación Química Española de la Industria del Cuero, 2000)En el presente trabajo se presenta una nueva metodología desarrollada para la determinación de cromo en licores de curtición y baños residuales, basada en la espectrofotometría y la utilización de calibración multivariante. ... -
Determination of carotenoids by liquid chromatography/mass spectrometry: effect of several dopants
(Springer Verlag, 2011)Various carotenoids were analyzed by ultra-high-pressure liquid chromatography with tandem mass spectrometry detection (UHPLC-MS/MS). Three different techniques to ionize the carotenoids were compared: electrospray ionization ... -
Determination of free metal ion concentrations using screen-printed electrodes and AGNES with the charge as response function
(Wiley, 2011)AGNES (Absence of Gradients and Nernstian Equilibrium Stripping) has been implemented with screen-printed electrodes (SPE) for the determination of the free concentration of Zn2+, Cd2+ and Pb2+. For SPE, the stripped charge ... -
Determination of free metal ion concentrations with AGNES in low ionic strength media
(Elsevier, 2013-01-15)The determination of free metal ion concentrations of heavy metals, like Zn2+ or Cd2+, with AGNES (Absence of Gradients and Nernstian Equilibrium Stripping) requires an adequate selection of parameters such as deposition ... -
Determination of free Zn2+ concentration in synthetic and natural samples with AGNES (Absence of Gradients and Nernstian Equilibrium Stripping) and DMT (Donnan Membrane Technique)
(Elsevier, 2012-04-01)The determination of free Zn2+ ion concentration is a key in the study of environmental systems like river water and soils, due to its impact on bioavailability and toxicity. AGNES (Absence of Gradients and Nernstian ... -
Determination of the complexing capacity of synthetic and real wine for Zn using Absence of Gradients and Nerstian Equilibrium Stripping technique
(American Chemical Society, 2013-02-06)The complexing capacity of synthetic (0.011 M tartrate in 13.5% ethanol) and real wine (Raimat Abadia) in titrations with added total Zn concentrations up to 0.03 M has been determined following the free Zn concentrations ... -
Determination of the free metal Ion concentration using AGNES Implemented with environmentally friendly bismuth film electrodes
(American Chemical Society, 2015-06-16)Ex-situ plated Bi film electrodes (Bi-FE) have been employed, for the first time, to measure the free concentration of Pb(II) in aqueous solutions using AGNES (Absence of Gradients and Nernstian Equilibrium Stripping) with ... -
Determination of the iodine value of biodiesel using 1H NMR with 1,4-dioxane as an internal standard
(Elsevier, 2010)Iodine values (IVs) of some biodiesel samples were analyzed using both 1H NMR and a standard iodometric method. 1H NMR was carried out with and without 1,4-dioxane as an internal standard (IS). The results obtained using ... -
Determination of Zn2+ concentration with AGNES using different strategies to reduce the deposition time
(Elsevier, 2005)Absence of gradient and Nernstian equilibrium stripping (AGNES) senses the free ion concentration of Zn(II) in solutions containing different ligands, being unaffected by the lack of reversibility of the Zn2+/Zn0 couple ... -
Development of aroma-synthesising capacity throughout fruit maturation of ‘Mondial Gala’ apples
(Taylor & Francis, 2008)Emission of aroma volatile compounds (AVCs) and the activity of some related enzymes were monitored during ontree maturation of ‘Mondial Gala’ apples. Volatile esters were quantitatively prominent among the AVCs ... -
Differential contribution of the two major polygalacturonases from Penicillium digitatum to virulence towards citrus fruit
(Elsevier, 2018-10)The fungus Penicillium digitatum is the causal agent of the citrus green mould, the major postharvest diseases of citrus fruit. Lesions on the surface of infected fruits first appear as soft areas around the inoculation ... -
Direct determination of free metal concentration by implementing stripping chronopotentiometry as second stage of AGNES
(The Royal society of Chemistry, 2011)The electroanalytical technique Absence of Gradients and Nernstian Equilibrium Stripping (AGNES) has been extended by applying stripping chronopotentiometry (SCP) as the re-oxidation stage in the determination of the free ... -
Direct determination of free Zn concentration in samples of biological interest
(Elsevier, 2022)The speciation of essential metal ions in biological fluids, such as blood plasma and serum, is of fundamental importance to understand the homeostasis of these elements. The activity of metal ions such as Zn2+ in extracellular ... -
Dispersive liquid–liquid microextraction and injection-port derivatization for the determination of free lipophilic compounds in fruit juices by gas chromatography-mass spectrometry
(Elsevier, 2017)A method consisting of dispersive liquid–liquid microextraction (DLLME) followed by injection-port derivatization and gas chromatography-mass spectrometry (GC–MS) for the analysis of free lipophilic compounds in fruit ... -
Dissolution and phosphate-induced transformation of ZnO nanoparticles in synthetic saliva probed by AGNES without previous solid-liquid separation. Comparison with UF-ICP-MS
(American Chemical Society, 2019-02-26)The variation over time of free Zn2+ ion concentration in stirred dispersions of ZnO nanoparticles (ZnO NPs) prepared in synthetic saliva at pH 6.80 and 37 degrees C was followed in situ (without solid liquid separation ... -
Dissolution Kinetics and Solubility of ZnO Nanoparticles Followed by AGNES
(American Chemical Society, 2012)There is a current debate on whether the toxicity of engineered ZnO nanoparticles (NPs) can be traced back to their nanoscale properties or rather to the simple fact of their relatively high solubility and consequent ... -
Dissolved concentrations and organic speciation of copper in the Amazon River estuary and mixing plume
(Elsevier, 2021-06-24)The Amazon is Earth's largest river by volume output, making it an important source of trace metals and dissolved organic matter (DOM) to the Atlantic Ocean. Despite major recent anthropogenic disruptions to the Amazon ... -
Dissolved iodide in marine waters determined with Diffusive Gradients in Thin-films technique
(Elsevier, 2021)For the first time, Diffusive Gradient in Thin-films (DGT) focuses on the inorganic iodine species iodate (IO3) and iodide (I). A silver-doped Cl resin (AgdCl), which is known to selectively accumulate I, was used to ...