Enginyeria Química i Química Analítica: Recent submissions
Now showing items 201-220 of 790
Multivariate curve resolution: a powerful tool for the analysis of conformational transitions in nucleic acids
A successful application is reported of the multivariate curve resolution alternating least‐squares method (MCR‐ALS) for the analysis of nucleic acid melting and salt‐induced transitions. Under conditions where several ...
Liquid-phase synthesis of butyl tert-butyl ether catalysed by ion-exchange resins: kinetic modelling through in-depth model discrimination
The kinetics of the butyl tert-butyl ether (BTBE) synthesis reaction over Amberlyst¿ 35 as the catalyst has been studied at 303-356 K in the liquid phase in two different reactor systems: batch and fixed-bed. Internal mass ...
Characterization of solute-solvent interactions in liquid chromatography systems: A fast method based on Abraham's linear solvation energy relationships
The Abraham's solvation parameter model, based on linear solvation energy relationships (LSER), allows the accurate characterization of the selectivity of chromatographic systems according to solute-solvent interactions ...
Study of the interaction of the palmatine alkaloid with hybrid G-quadruplex/duplex and i-motif/duplex DNA structures
There is an increasing interest in the study of guanine or cytosine-rich sequences that may fold into G-quadruplex (G4) or i-motif (iM) structures showing a short hairpin (or stem-loop) stabilized by Watson-Crick base ...
Evaluation of on-line solid-phase extraction capillary electrophoresis-mass spectrometry with a nanoliter valve for the analysis of peptide biomarkers
On-line solid-phase extraction capillary electrophoresis-mass spectrometry (SPE-CE-MS) is a powerful technique for high throughput sample clean-up and analyte preconcentration, separation, detection, and characterization. ...
A novel methodology for the determination of neutral perfluoroalkyl and polyfluoroalkyl substances in water by gas chromatographyatmospheric pressure photoionisation-high resolution mass spectrometry
Here, we developed and validated a new gas chromatography-atmospheric pressure photoionisation high-resolution mass spectrometry (GC-APPI-HRMS) method combined with headspace solid-phase microextraction (HS-SPME) for the ...
Proyecto Institucional de Fomento de la Calidad Docente en la Facultad de Química de la Universidad de Barcelona (UB)
Se presenta el Proyecto Institucional de Fomento de la Calidad Docente de la Facultad de Química, promovido por el decanato y por el VR de Docencia de la UB, en el marco del Proyecto de Investigación, Mejora e Innovación ...
Equations for the Correlation and Prediction of Partition Coefcients of Neutral Molecules and Ionic Species in the Water-Isopropanol Solvent System
We use literature data on solubilities of 46 compounds in the water-isopropanol (IPA) system to obtain the corresponding partition coefficients, P, for transfer from water to water- IPA mixtures. We have then used our ...
A new multivariate standard addition strategy for stripping voltammetric electronic tongues: application to the determination of Tl(I) and In(III) in samples with complex matrices
A new multivariate standard addition strategy applicable to stripping methods was proposed as an extention of the classical univariate standard addition method for the resolution of complex samples involving overlapped ...
Equilibrium solubility measurement of ionizable drugs-consensus recommendations for improving data quality
This commentary addresses data quality in equilibrium solubility measurement in aqueous solution. Broadly discussed is the 'gold standard' shake-flask (SF) method used to measure equilibrium solubility of ionizable drug-like ...
Encapsulation of ginger oil in alginate-based shell materials
Hydrogels consisting of a blend of sodium alginate and k -carrageenan aqueous solutions were prepared using Ca 2+ as the gelling agent in a shell material formulation for encapsulation of food-grade ginger oil. A preliminary ...
Evaluation of the Ability of PAMPA Membranes to Emulate Biological Processes through the Abraham Solvation Parameter Model
Two parallel artificial membrane permeability assay (PAMPA) systems intended for emulating skin permeability have been characterized through the solvation parameter model of Abraham using multilinear regression analysis. ...
Determination of the retention factor of ionizable compounds in microemulsion electrokinetic chromatography
Determination of the retention factor of ionized compounds in microemulsion electrokinetic chromatography requires two mobility measurements at the same pH: one in the presence of the microemulsion and another in plain ...
Anaerobic co-digestion effluent as substrate for chlorella vulgaris and scenedesmus obliquus cultivation
Anaerobic digestate supernatant can be used as a nutrient source for microalgae cultivation, thus integrating phytoremediation processes with high value products storage in microalgae biomass. Microalgae are able to use ...
Determination of phthalic acid esters in drinking water and olive oil by ultra-high performance liquid chromatography-electrospray-tandem mass spectrometry: Study of phthalate migration from plastic bottles to drinking water at different domestic exposure conditions
A UHPLC-ESI-MS/MS method for the determination of ten phthalates in mineral water and olive oil samples was developed. A hold-back column placed between pump and injection valve allowed preventing phthalate instrumental ...
Tailored Jeffamine molecular tools for ordering mesoporous Silica
Herein, we report the formation of organized mesoporous silica materials prepared from a novel nonionic gemini surfactant, myristoyl-end capped Jeffamine, synthesized from a polyoxyalkyleneamine (ED900). The behavior of ...
Pulsed amperometric detection: Extending the applicability of HPLC to substances with two-step redox processes.
Electrochemical detection coupled to liquid chromatography provides high selectivity compared to optical detection due to the lower number of electrochemically active compounds. Nevertheless, not all electrochemically ...
Lipophilicity of amphoteric and zwitterionic compounds: a comparative study of determination methods
Common drugs intended for action in plasma (antibacterials, antiallergics, diuretics¿) often display both acidic and basic behavior, and some of these amphoteric compounds can appear as zwitterions. In such cases, accurate ...
Antimony in Polyethylene Terephthalate-Bottled Beverages: The Migration Puzzle
A novel strategy to assess the main variables that potentially affect the migration of antimony from PET bottles to beverages, including mineral waters and juices, is herein proposed. In a preliminary step, an LC-ICP-MS ...
A chemometric survey about the ability of voltammetry to discriminate pharmaceutical products from the evolution of signals as a function of pH.
Many pharmaceutical products are electroactive and, therefore, can be determined by voltammetry. However, most of these substances produce signals in the same region of oxidative potentials, which makes it difficult to ...
