https://hdl.handle.net/2072/478813 Thu, 09 Apr 2026 01:38:11 GMT 2026-04-09T01:38:11Z https://hdl.handle.net/2445/228682 A new method for the determination of $^{210}Po$ in environmental samples using plastic scintillation resins Rotger, Jordi.; Tent Petrus, Joana Ma.; Bagán Navarro, Héctor; Rigol Parera, Anna; Tarancón Sanz, Alex We have developed a new method using a selective plastic scintillation resin (PSresin) based on Aliquat-336 for analysing 210Po in water samples. The PSresin effectively isolates 210Po while removing main interferences such as 210Pb and 210Bi by loading the sample in a HCl 1 mol L−1 medium and rinsing with HCl 1 mol L−1 and 6.25 mol L−1, consecutively. We optimized the rinse volumes and conducted a search for suitable chemical analogues of polonium to be used as tracers throughout the procedure. Zinc and cadmium were identified as the most suitable elements for preconcentration and separation of 210Po on the PSresin. We compared our PSresin method with reference methods (UNE-EN ISO 13161 and IAEA/AQ/12) based on alpha spectrometry by analysing drinking water samples. The results showed that the PSresin method is faster and provides accurate results, although the alpha spectrometry methods achieve lower detection limits. Tue, 07 Apr 2026 14:37:01 GMT https://hdl.handle.net/2445/228682 2026-04-07T14:37:01Z https://hdl.handle.net/2445/222206 Bioaggregachromism of Asymmetric Monomethine CyanineDyes as Noncovalent Binders for Nucleic Acids Ilieva, Sonia; Petkov, Nikolay; Gargallo Gómez, Raimundo; Novakov, Christo; Ragelow, Miroslav; Todorova, Nadezhda; Vasilev, Aleksey; Chesmedzhieva, Diana Two new asymmetric monomethine cyanine dyes, featuring dimethoxy quinoliniumor methyl quinolinium end groups and benzothiazole or methyl benzothiazole endgroups were synthesized. The chemical structures of the two dyes—(E)-6,7-dimethoxy-1-methyl-4-((3-methylbenzo[d]thiazol-2(3H)-ylidene)methyl)quinolin-1-ium iodide (3a) and(E)-4-((3,5-dimethylbenzo[d]thiazol-2(3H)-ylidene)methyl)-1,2-dimethylquinolin-1-ium iodide(3b)—were confirmed through NMR spectroscopy and MALDI-TOF mass spectrometry.A new methodology was developed to study monocationic dyes in the absence of amatrix and cationizing compounds in MALDI-TOF mass experiments. The newly synthesizeddyes contain hydrophobic functional groups attached to the chromophore, enhancingtheir affinity for the hydrophobic regions of nucleic acids within the biological matrix. Thedyes’ photophysical properties were investigated in aqueous solutions and DMSO, as wellas in the presence of nucleic acids. The dyes exhibit notable aggregachromism in both pureaqueous and buffered solutions. The observed aggregation phenomena were further elucidatedusing computational methods. Fluorescence titration experiments revealed that uponcontact with nucleic acids, the dyes exhibit bioaggregachromism–aggregachromism on thesurfaces of the respective biomolecular matrix (RNA or DNA). This bioaggregachromismwas further confirmed by CD spectroscopy. Given the pronounced aggregachromismdetected, we conclude that the dyes investigated in this study are highly suitable for useas fluorogenic probes in biomolecular recognition techniques. The unique absorption andfluorescence spectra of these dyes make them promising fluorogenic markers for variousbioanalytical methods related to biomolecular recognition. Mon, 14 Jul 2025 11:59:58 GMT https://hdl.handle.net/2445/222206 2025-07-14T11:59:58Z https://hdl.handle.net/2445/218283 Mejora del aprendizaje en química analítica a través de actividades teórico-prácticas: acercar el laboratorio al aula y el aula al laboratorio Fuguet i Jordà, Elisabet; Amézqueta, Susana; Guiteras, Jacinto; López, José Fermin; Rigol Parera, Anna; Benavente Moreno, Fernando J. (Julián) Un problema recurrente en los estudios de Química es la dificultad que presenta el estudiantado para relacionar los conceptos teóricos con las aplicaciones prácticas y viceversa. En este trabajo se muestra el desarrollo de dos actividades de Química Analítica básica, dirigidas a una asignatura teórica y a otra práctica, con la finalidad de interrelacionar sus conocimientos y mejorar los aprendizajes. En la asignatura teórica se ha introducido una sesión de laboratorio demostrativa que da pie a una actividad que se trabaja simultáneamente a las explicaciones teóricas del profesor sobre equilibrios en disolución. En la asignatura práctica se ha profundizado en los conceptos teóricos de una valoración potenciométrica a partir de la reproducción del experimento con un simulador. En ambos casos las valoraciones, tanto por parte del profesorado como del alumnado, han sido altamente positivas y se ha constatado que ambas actividades cumplen el propósito para el cual fueron diseñadas. Thu, 30 Jan 2025 18:42:33 GMT https://hdl.handle.net/2445/218283 2025-01-30T18:42:33Z https://hdl.handle.net/2445/207250 Recovery of rare earth elements from acidic mine waters by integration of a selective chelating ion-exchanger and a solvent impregnated resin Hermassi, H.; Granados i Juan, Mercè; Valderrama, C,; Ayora, C.; Cortina Pallàs, José Luis A polymeric ion-exchange resin, incorporating methyl-amino-phosphonic (TP260) functionalities, and a solvent impregnated resin (SIR) incorporating tri-methylpentylphosphinic acid (TP272), were evaluated for the selective separation of Rare Earth Elements (REE) from Transition (TE), post -Transition (PTE), and Alkaline Earth (AE) Elements in acidic mine waters (AMW). The influence of the functional groups nature and the acidity dependence were studied and their effects on efficiencies for REE removal and separation from TE/PTE were analysed Both resins provided good separation factors of REE from TE/PTE by acidity control of the treated effluent once Fe(III), the major component in AMW, had been removed by precipitation. The TP272 resin, containing tri-methylpentylphosphinic acid (Cyanex 272) onto the polymeric network, showed higher affinity towards Heavy REE (HRRE) than for Light REE (LRRE) by acidity control (pH > 4). Higher pre-concentration factors were achieved for TP272 impregnated resin (e.g., 20–30) in comparison with the TP260 phosphonic resin (2−5), as the pH extraction window is in the moderate pH region (1−5). The integration in series of both resins could be used to separate and recover HREE and LREE from TE/PTE from AMW generated concentrates could be used to recover REE as secondary resources for the clean energy technology industry. Wed, 07 Feb 2024 16:52:19 GMT https://hdl.handle.net/2445/207250 2024-02-07T16:52:19Z