Dipòsit Digital de la Universitat de Barcelona
El Dipòsit Digital de la Universitat de Barcelona és el repositori institucional que conté en format digital els materials derivats de l'activitat docent, investigadora i institucional de la comunitat universitària.
Enviaments recents
ArticleAuthentication of flours using chromatographic and spectroscopic techniques: A comprehensive review(Elsevier B.V., 2026-07-23) Pages-Rebull, J.; Serrano i Plana, Núria; Díaz Cruz, José Manuel; Pérez Ràfols, Clara; Ozen, Banu; Tokatli, FigenBackground: Flour is a powdered substance obtained by grinding cereal grains or other starch-rich foods, formed through a milling process that reduces the grain to a fine powder. Flour is a staple ingredient highly susceptible to adulteration, mislabelling, and cross-contamination, posing risks to food safety, quality, and consumer trust. The increasing complexity of flour matrices and supply chains has intensified the need for reliable analytical tools for authentication. Scope and approach: This review systematically evaluates recent advances in chromatographic and spectroscopic techniques for flour authentication, covering studies from 2015 to 2025 (chromatography) and 2020–2025 (spectroscopy). Both targeted and non-targeted approaches are discussed, including GC, LC, and CE, as well as NIR, FTIR, hyperspectral imaging, fluorescence, Raman, and LIBS. Particular attention is given to chemometric and machine learning strategies for classification and quantification, alongside key methodological considerations such as sample preparation, data processing, and validation. Key findings and conclusions: Chromatographic methods provide high sensitivity and molecular specificity, enabling targeted detection of markers, while spectroscopic techniques offer rapid, non-destructive, and high-throughput screening based on chemical fingerprints. Despite significant progress, major challenges remain, including matrix complexity, environmental variability, limited standardization, and poor model transferability across instruments and datasets. Detection of low-level adulteration in complex or blended flours remains particularly challenging. Future research is expected to focus on multi-sensor data fusion, expansion of open spectral databases, robust validation frameworks, and integration of portable devices with digital infrastructures. These developments will be essential to improve robustness, scalability, and real-world implementation of flour authentication strategies.- ArticleAtomically-dispersed transition metal electrocatalysts supported on lignin-derived carbons for cathodic hydrogen peroxide synthesis using a gas-diffusion electrode(Elsevier B.V., 2026-05-14) Zuccante, G.; Escaja Sánchez, Nuria; Sirés Sadornil, Ignacio; Muhyuddin, Mohsin; Santoro, CarloHydrogen peroxide (H2O2) is nowadays a commodity chemical, with a particularly relevant application in wastewater treatment. However, its industrial production is energy demanding, highly polluting and potentially dangerous. Lately, oxygen reduction reaction (ORR) conducted on a gas-diffusion electrode (GDE) has been explored to deploy a more sustainable synthesis route. In this work, a set of lignin-derived carbons, either metal-free or loaded with atomically dispersed transition metals (Fe, Co and Ni), was successfully synthesized for the electrogeneration of H2O2. For some electrocatalysts, the rotating ring-disk electrode (RRDE) analysis showed a peroxide selectivity () over 90% and a number of transferred electrons of ∼2. Accordingly, the type of metal and the carbon porosity had a major influence on the performance of GDEs during bulk electrolysis. In galvanostatic assays conducted in 0.05 M Na2SO4 medium at pH 5.9 and 10 mA cm−2, the carbon obtained from direct lignin pyrolysis at 400 °C outperformed a commercial GDE, showing the highest H2O2 yield (13.8 mM after 360 min), with a maximum current efficiency of 85% and relatively low energy consumption (∼ 8 ). Such optimum performance is related to its optimal porosity and hydrophobicity. Moreover, upon functionalization with Fe, an effective electro-Fenton (EF) catalyst was obtained, allowing a 97% removal of the drug lisinopril using only 0.1 g L−1 of suspended catalyst. This work demonstrates the possibility of producing cost-effective electrocatalysts from waste for H2O2 production and wastewater treatment.
- ArticleEvaluating the stability and efficiency of Fe(III)-DTPA complex for prednisolone degradation by solar photoelectro-Fenton process at neutral pH(Elsevier B.V., 2026-07-17) Tirira, Paola; Díaz Redondo, Ivan; Lopez Vinent, Nuria; Zhou, Minghua; Cabot Julià, Pere-Lluís; Sirés Sadornil, IgnacioThe stability of the Fe(III)-DTPA complex for its use as a promising homogeneous catalyst to solve the pH bottleneck in solar photoelectro-Fenton (SPEF) process was evaluated for the first time. Viability depends on its resistance to photodegradation and attack by reactive oxygen species; ideally, it should allow sufficient release of free iron catalyst while preserving ligand stability to prevent iron precipitation. Here, Fe(III)-to-ligand molar ratio was first optimized to ensure complete chelation within a wide pH range, as well as high photostability against UVA and sunlight and resistance to •OH attack. Results showed that Fe(III)-DTPA complex at ratios of 1:1 and 1:2 remained stable at pH 3–9 for at least 180 min. Notably, the 1:2 complex exhibited superior photostability and oxidative resistance during SPEF treatment, minimizing the iron precipitation. As a proof of concept, removal of the glucocorticoid prednisolone (PREDN) by SPEF at pH 7 was investigated. Complete degradation of 0.055 mM PREDN in 50 mM Na2SO4 medium containing 0.05 mM Fe(III)-DTPA (1:2) was achieved after 90 min at 30 mA cm−2. Although 95% of the complex was also degraded, the organic species derived from iron complex maintained a significant percentage of soluble iron (> 40%). Additionally, phytotoxicity and QSAR tests revealed that an initially pronounced toxicity due to by-products generated from DTPA and PREDN resolved into a non-toxic mixture with enhanced biodegradability. Therefore, Fe(III)-DTPA complex (1:2) can be considered a sustainable catalyst for SPEF treatment of drugs at circumneutral pH, combining acceptable operational stability and environmental safety.
- ArticleTracking Microhydration of the NaCl Rocksalt Molecule by Quantum Chemical Calculations and Penning Ionization Electron Spectroscopy in Helium Nanodroplets(Wiley-VCH, 2026-05-01) Pi Pericay, Martí; Barranco Gómez, ManuelThe microhydration of rock salt (NaCl) molecules was investigated theoretically by density-functional theory and force field calculations and experimentally by high-resolution Penning ionization electron spectroscopy (PIES) in helium nanodroplets. The calculations reveal a transition from contact ion pair structures to solvent-separated ion pairs at n = 12–15. However, it takes n % 17 water molecules to form a complete solvation shell around the Cl− anion and as many as n % 34 to fully hydrate the Na+ cation, thus the entire NaCl molecule. Although NaCl molecules are predicted to be fully submerged inside the droplets, the PIES of NaCl are highly resolved, in stark contrast to other molecular species. Codoping the droplets with a controlled number of n = 1–10 water molecules leads to efficient quenching of the NaCl Penning ionization signal and to its full suppression for n ≳ 30, in line with the calculations.
- ArticleTracking Microhydration of the NaCl Rocksalt Molecule by Quantum Chemical Calculations and Penning Ionization Electron Spectroscopy in Helium Nanodroplets(Wiley-VCH, 2026-05-01) Pi Pericay, Martí; Barranco Gómez, Manuel; Ltaief, LB; Sishodia, Keshav; Richter, Robert; Eloranta, Jussi; Krishnan, Sivarama; Calvo, Florent; Mudrich, MarcelThe microhydration of rock salt (NaCl) molecules was investigated theoretically by density-functional theory and force field calculations and experimentally by high-resolution Penning ionization electron spectroscopy (PIES) in helium nanodroplets. The calculations reveal a transition from contact ion pair structures to solvent-separated ion pairs at n = 12–15. However, it takes n % 17 water molecules to form a complete solvation shell around the Cl− anion and as many as n % 34 to fully hydrate the Na+ cation, thus the entire NaCl molecule. Although NaCl molecules are predicted to be fully submerged inside the droplets, the PIES of NaCl are highly resolved, in stark contrast to other molecular species. Codoping the droplets with a controlled number of n = 1–10 water molecules leads to efficient quenching of the NaCl Penning ionization signal and to its full suppression for n ≳ 30, in line with the calculations.