Articles publicats en revistes (Enginyeria Química i Química Analítica)

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Analytical methods for cinnamon authentication
(Elsevier B.V., 2024-04-01) Pages-Rebull, Josep; Pérez Ràfols, Clara; Serrano i Plana, Núria; Díaz Cruz, José Manuel
Cinnamon is a widely marketed spice used in worldwide cuisines and medicinal applications. Although Cinnamomum verum is considered as “true cinnamon”, other cinnamon species (particularly Cinnamomum cassia) are also commercialized. The higher price of Cinnamomum verum makes it vulnerable to adulteration mainly by the addition of products of the same class, which also results in a health issue as Cinnamomum cassia presents a higher content of the hepatoxic compound coumarin. Scope and approach This review discusses the most important aspects of cinnamon authentication from an analytical perspective, focusing on analytical techniques and chemometric methods, and emphasizing the differences between targeted and non-targeted approaches. Additionally, the most common analytical markers employed in the authentication of cinnamon are summarized. Key findings and conclusions Targeted analysis is mainly based on either liquid or gas chromatography, as they allow the quantification of a large number of compounds, particularly when coupled to mass spectrometry. The most common analytical markers in cinnamon authentication are cinnamaldehyde, coumarin, eugenol, and cinnamyl alcohol. In contrast, more straightforward techniques like nuclear magnetic resonance or infrared spectroscopy, which can directly analyse solid samples, are usually preferred for non-targeted analysis. Regarding chemometrics, most studies are limited to exploratory analysis and the ones employing classification chemometric methods are mostly devoted to the differentiation among cinnamon species. The quantification of partial adulterations is still an on-going research field, although this is a likely case of adulteration in the current market.
Application of Raman and chemometrics to the mechanochemical synthesis of 4,4-bipyridine/cobalt based MOF using twin screw extrusion
(Elsevier B.V., 2024-03-15) Metawea, Ahmed; Soto López, Rodrigo; Khraisheh, Majeda; Walker, Gavin; Albadarin, Ahmad B.
The process optimization of 4,4-bipyridine based metal organic framework (MOF) synthesis by twin screw extrusion (TSE) is investigated using cobalt nitrate hexahydrate (Co(NO3)2·6H2O) as the metal precursor. The effects of operating parameters including liquid to solid ratio (L/S), screw speed and feeding rate on the product composition are examined. The collected MOF samples were characterized offline by powder X-ray diffraction, Raman spectroscopy, thermogravimetric analysis, and scanning electron microscopy. It was found that the explored feeding and screw rates are insufficient to generate a pure MOF. However the MOF product was obtained using an optimum L/S ratio i.e., 0.5, which improved the wettability and mixing of reactants to allow effective interactions at a molecular level, facilitating the complete reaction inside the extruder. Partial least square based multivariate analysis of the collected Raman spectra was used to obtain predictive models to quantify MOF purity, which reached a maximum of 87.0 wt% using 0.5 L/S, 100 g/h feeding rate and 100 rpm screw speed.
Analysing polypeptide antibiotics residues in animal muscle tissues: The crucial role of HRMS
(Elsevier B.V., 2024-06-15) Rúbies Prat, Antoni; Beguiristain Seguí, Iñaki; Tibon, Jojo; Cortés Francisco, Nuria; Granados i Juan, Mercè
High resolution mass spectrometry (HRMS) has undergone an exciting phase of technological evolution. Time of flight instruments with significantly higher resolution and larger dynamic range have become available. Furthermore, a new type of mass spectrometer, the Orbitrap gave a significant impetus to high resolution mass spectrometry. These instruments are directly challenging the more traditional tandem mass spectrometers (QqQ). Recent studies show that sufficiently high resolving HRMS instrumentation is not only suited for screening but can be used for reliable quantitative purposes. HRMS should be able to dislodge QqQ in most analytical fields when some currently still existing HRMS hard and even more relevant software related limitations will be solved.
Application of HPLC-UV combined with chemometrics for the detection and quantification of ‘true cinnamon’ adulteration
(Elsevier B.V., 2024-05-01) Pages-Rebull, J.; Sagristà, Gemma; Pérez Ràfols, Clara; Serrano i Plana, Núria; Díaz Cruz, José Manuel
Cinnamon is one of the most popular spices used in cuisines worldwide. Among its different species, Ceylon cinnamon (“true cinnamon") is the one with the most health benefits due to its high concentration in the antioxidant eugenol and the ultra-low content of the hepatotoxic compound coumarin. However, the higher price of Ceylon cinnamon makes it vulnerable to fraudulent adulteration with more economic species of cinnamon, such as Cassia and Saigon. Thus, for the detection of frauds in cinnamon samples, a HPLC-UV method was developed for the determination of 4 characteristic cinnamon compounds: eugenol, cinnamaldehyde, coumarin and cinnamic acid. The obtained data were analyzed by PLS to attain not only the authentication of cinnamon species but also the detection and quantification of partial adulterations. Several mixtures prepared in the laboratory using different cinnamon powder samples considered ‘pure’ Ceylon, Cassia or Saigon were tested, concluding that the proposed approach allows a clear identification of Ceylon cinnamon and a suitable quantification of the Ceylon: non-Ceylon ratio regardless of the commercial sample selected (RMSE <0.06 for both training and test sets).
Resilience towards organic load and activated sludge variations in co-fermentation for carboxylic acid production
(Elsevier B.V., 2024) Perez-Esteban, N.; Vives-Egea, Júlia; Dosta Parras, Joan; Astals Garcia, Sergi; Peces, Miriam
Two perturbations were investigated in acidogenic co-fermentation of waste activated sludge (WAS) and food waste in continuous mesophilic fermenters: increasing the organic loading rate (OLR) and changing the WAS. A control reactor maintained an OLR of 11 gVS/(L·d), while a test reactor had a prolonged OLR change to 18 gVS/(L·d). For each OLR, two WAS were studied. The change in OLR led to differentiated fermentation product profile without compromising the fermentation yields (∼300 mgCOD/gVS). At 11 gVS/(L·d), the product profile was dominated by acetic, butyric, and propionic acids while at 18 gVS/(L·d) it shifted to acetic acid, ethanol, and caproic acid. Reverting the OLR also reverted the fermentation profile. The biomass immigration with the WAS changed the fermentation microbial structure and introduced acetic acid-consuming methanogens, which growth was only delayed by the OLR increase. Microbial monitoring and post-fermentation tests can be used for early detection of acetic acid-consuming events.
Integrated Biofilm Dispersion and Virulence Responsiveness for Targeted Treatment of Pseudomonas aeruginosa Infection in Lungs
(Wiley-VCH, 2024-10-08) Ivanov, Ivan; Tzanov, Tzanko; Ivanova, Kristina; Ramon, Eva; Wnorowska, Urszula; Todorova, Katerina; Ivanova, Aleksandra; Bastos-Arrieta, Julio; Puertas-Segura, Antonio; Deptula, Piotr; Damyanova, Tsvetozara; Paunova-Krasteva, Tsvetelina; Bucki, Robert
The self-organization of microbes into biofilms provides multiple benefits including tolerance to mechanical stress and resistance to immune defences and antibiotics. Coupled to a compromised mucociliary function, these traits have dire consequences in cystic fibrosis patients – persistent infections are the main reason for morbidity and mortality. Thereby, disease progression is associated with universal colonization by Pseudomonas aeruginosa, which selects for a slimy phenotype to adapt to the lung microenvironment. Recognizing this, drug-delivery vehicles that break down the mucoid extracellular matrix made of alginate are designed to enable better penetration and biofilm dispersion. In parallel, a protective layer responds to the proteolytic activity of the pathogen and thus controls drug availability. To realize this architecture, silica nanoparticles are loaded with imipenem, and then coated with elastin and alginate lyase in a layer-by-layer fashion using ultrasound. The nanoscale formulations eradicate up to 80% of the total biomass and reduce the bacterial viability in biofilms by 3 logs, considerably outperforming the bulk antibiotic in vitro, whereby the effects are correlated to changes in the viscoelasticity. Furthermore, the stimuli-responsive nanocarriers are safe and effective in animal models of P. aeruginosa infection, presenting a considerable therapeutic promise in the challenging context of lung diseases.
PET-Driven Fluorescence Modulation in Halochromic Styryl Hemicyanine Dyes Targeting DNA Minor Groove
(MDPI, 2025-11-30) Aleksandrova, Teodora; Pashev, Aleksandar; Ilieva, Sonia; Gargallo Gómez, Raimundo; Cheshmedzhieva, Diana; Vasilev, Aleksey
A new series of styryl hemicyanine dyes featuring substituted N-phenylpiperazine end groups was synthesized using an environmentally friendly procedure. The photophysical properties of the dyes were systematically investigated in organic solvents of varying polarity and when bound to DNA, using a combination of spectroscopic techniques. The dyes show strong negative solvatochromism and exhibit fluorescence quenching upon DNA binding. The dyes are definitely halochromic, exhibiting pronounced fluorescent acidochromism, accompanied by a photoinduced electron transfer (PET) effect. Titration with acid of the dye–DNA complexes restores fluorescence, indicating suppression of the PET and, at the same time, rigidizing of the chemical structure. UV/VIS and fluorescence titration, circular dichroism spectroscopy, and molecular docking methods were used to investigate the interaction mode between the dyes and DNA. Density functional theory (DFT) and time-dependent density functional theory (TDDFT) quantum chemical calculations were employed in deciphering the observed spectroscopic behavior and PET-related effects. The obtained results suggest the dyes’ potential as pH-responsive fluorescent probes for nucleic acid environments.
Study of Total Ammoniacal Nitrogen Recovery Using Polymeric Thin-Film Composite Membranes for Continuous Operation of a Hybrid Membrane System
(MDPI, 2025-06-18) Shahgodari, Shirin; Llorens Llacuna, Joan; Labanda, Jordi
This study examined total ammoniacal nitrogen (TAN) rejection by two reverse osmosis (RO) and two nanofiltration (NF) membranes as a function of pH for three ammonium salts to optimize conditions for a hybrid membrane system that can produce high-purity TAN streams suitable for reuse. The results showed that TAN rejection was significantly influenced by membrane type, feed pH, and the ammonium salt used. This study represents the first attempt to simulate real manure wastewater conditions typically found in pig manure. TAN rejection for (NH4)2SO4 and NH4HCO3 reached up to 95% at pH values below 7, with the SW30 membrane showing the highest performance (99.5%), attributed to effective size exclusion and electrostatic repulsion of SO42− and HCO3 ions. In contrast, lower rejection was observed for NH4Cl, particularly with the MPF-34 membrane, due to its higher molecular weight cut-off (MWCO), which diminishes both exclusion mechanisms. TAN rejection decreased markedly with increasing pH across the BW30, NF90, and MPF-34 membranes as the proportion of uncharged NH3 increased. The lowest rejection rates (<15%) were recorded at pH 11.5 for both NF membranes. These results reveal a notable shift in separation behavior, where NH3 permeation under alkaline conditions becomes dominant over the commonly reported NH4+ retention at low pH. This novel insight offers a new perspective for optimizing membrane-based ammonia recovery in systems simulating realistic manure wastewater conditions. TAN recovery was evaluated using a hybrid membrane system, where NF membranes operated at high pH promoted NH3 permeation, and the SW30 membrane at pH 6.5 enabled TAN rejection as (NH4)2SO4. This hybrid system insight offers a new perspective for optimizing membrane-based ammonia recovery in systems simulating realistic manure wastewater conditions. Based on NH3 permeation and membrane characteristics, the NF90 membrane was operated at pH 9.5, achieving a TAN recovery of 48.3%, with a TAN concentration of 11.7 g/L, corresponding to 0.9% nitrogen. In contrast, the MPF-34 membrane was operated at pH 11.5. The NF90–SW30 system also achieved a TAN recovery of 48.3%, yielding 11.7 g/L of TAN with a nitrogen content of 1.22%. These nitrogen concentrations indicate that both retentate streams are suitable for use as liquid fertilizers in the form of (NH4)2SO4. A preliminary economic assessment estimated the chemical consumption cost at 0.586 EUR/kg and 0.729 EUR/kg of (NH4)2SO4 produced for the NF90–SW30 andMPF-34–SW30 systems, respectively.
Authentication of Honey Geographical Origin Using Liquid Chromatography-Low Resolution Mass Spectrometry (LC-LRMS) Fingerprints
(Springer Science + Business Media, 2026) Mostoles, Danica; Mara, Andrea; Sanna, Gavino; Saurina, Javier; Sentellas, Sonia; Núñez Burcio, Oscar
Honey is a natural sweetener produced by honeybees and is widely appreciated by consumers because of its multiple beneficial properties. Because of its high value, honey is placed as a targeted product for fraudulent practices. In this work, LC-LRMS fingerprinting was employed for classifying honey samples from 10 countries. Good classification and prediction performance were achieved based on a classification decision tree by consecutive paired PLS-DA models using a hierarchical model builder (HMB), obtaining sensitivity and specificity values higher than 83.3% and 92.6%, respectively, except for the case of China versus Japan. Tentative association of some phenolic compounds was accomplished, which provides useful chemical markers for country discrimination. For instance, methoxyphenylacetic acid, previously identified in New Zealander honeys, was tentatively annotated to m/z 165.0, detected in honey from New Zealand and Australia. The prediction of “unknown” samples was successful for most cases, obtaining sensitivity and specificity values of 100% for most countries. Good classification based on the continent of production was also accomplished, obtaining perfect discrimination among samples produced in Oceania and good classification performance was observed in Asian and European samples. Finally, the obtained fingerprints demonstrated to be useful chemical descriptors to quantify, as a proof of concept, adulterated Spanish honey with honey from Italy, China, and Serbia using partial least squares (PLS) regression, obtaining internal and external validation prediction errors lower than 23%.
Dealing with missing data blocks in Multivariate Curve Resolution. Towards a general framework based on a single factorization model.
(Elsevier B.V., 2024) Gómez Sánchez, Adrián; Ruckebusch, Cyril; Tauler Ferré, Romà; Juan Capdevila, Anna de
Multivariate Curve Resolution (MCR) deals with the mixture analysis problem by decomposing a data set with mixed information into a bilinear model of pure component contributions. Multiset analysis deals with fused data blocks linked to related experiments and/or techniques. Nevertheless, experiments and techniques often show differences that lead, when concatenated, to incomplete multisets with missing blocks of information. Incomplete multisets aim at incorporating all available information in the initial blocks of measurements but require adapted algorithms to be properly handled. This work presents the evolution of the different perspectives adopted to analyze incomplete multisets with advantages and drawbacks. Finally, a new methodology is proposed that adapts to any data configuration with missing entries without the need to perform data imputation or multiple factorizations. The new method adapts very well to analytical applications where the blocks of information to be fused are not acquired in equivalent experimental conditions.
Consistent acidogenic co-fermentation of waste activated sludge and food waste under thermophilic conditions
(Elsevier Ltd., 2025) Pérez Esteban, Noemí; Tully, Rose; Peces, Miriam; Dosta Parras, Joan; Astals Garcia, Sergi
Acidogenic co-fermentation of waste activated sludge (WAS) and food waste (FW) under thermophilic conditions enhances process consistency, while overcoming the problem of acetic acid consumption due to growing methanogens. Two long-term continuous co-fermentation experiments were carried out with a WAS:FW mixture (70:30 % in VS) at organic loading rate of 8 gVS/(L·d). Experiment 1 assessed the impact of temperature (35 °C and 55 °C) and WAS origin (WAS_A and WAS_B) in two collection periods. Experiment 2 evaluated the consistency at 55 °C by testing three WAS origins (WAS_A, WAS_B and WAS_C) in 3 additional collection periods. Experimental results showed that at 55 °C, the solubilisation yield was enhanced compared to 35 °C, although this did not always lead to higher fermentation yield. The fermentation product profile was affected by the operating temperature, with 55 °C promoting the accumulation of acetic and butyric acids. Acetic acid consumption was only detected at 35 °C in fermenters treating WAS_A, whereas it was not observed in fermenters treating WAS_B. This consumption was prevented at 55 °C, as none of the 13 fermenters continuous operation showed acetic acid consumption. Acetic acid consumption was attributed to species midas_s_9557 (genus Methanosarcina), an aceticlastic methanogen, which did not grow under 55 °C. Temperature had a more significant effect on the microbial community structure than WAS origin. Functional redundancy was demonstrated by each fermenter having its own distinct microbial consortium while maintaining constant metabolic functions at 55 °C. Overall, the acidogenic co-fermentation of WAS and FW at 55 °C is regarded as a robust and consistent biotechnology.
Construction and validation of parametric models to predict radiumsorption in soils
(Elsevier B.V., 2024-06-10) Serra Ventura, Joan; Vidal Espinar, Miquel; Rigol Parera, Anna
Elucidating the factors affecting the transfer of naturally occurring radionuclides (NOR) between environmental compartments is a key part of the assessment of ecosystem's exposure to naturally occurring radionuclide materials (NORM). For that, the sorption and desorption solid-liquid distribution coefficients (Kd) of radium (Ra) were quantified in a collection of 31 soil samples with contrasting edaphic properties under controlled conditions in laboratory batch experiments. Ra sorption was demonstrated to be moderate to high, with Kd (Ra) values ranging from 102 to 103 L kg−1. Ra sorbed was mostly irreversible, as evidenced by desorption percentages lower than 2 %. An exploratory analysis with partial least squares (PLS) regression identified the soil properties that correlated with Kd (Ra) and discarded those that were not relevant for describing Kd variability. A dataset of the sorption Kd (Ra) values and associated soil properties was built from our own data and from the literature after performing an in-depth review of similar Ra sorption studies. For the first time, Kd (Ra) parametric prediction models were constructed using univariate linear regression (ULR) and multivariate linear regression (MLR). Ra sorption in soils was mostly explained by the soil properties directly or indirectly related to the available exchange sites, such as the levels of water-soluble and exchangeable Ca and Mg as well as the pH of the contact solution. The most promising models explained around 80 % of the Kd (Ra) data variance, only needing Kd (Ca + Mg) or additional soil descriptors such as pH, Mn content, and the specific surface area. The validation of the proposed models confirmed that Kd (Ra) can be predicted with only a few soil properties that can be characterised in routine analysis. Thus, the proposed models could be used to estimate the interaction of Ra in soils in risk assessment.
Phosphorus recovery via vivianite precipitation in anaerobic digestion and fermentation processes: A comprehensive review
(Elsevier B.V., 2025-10-13) Aguilar-Pozo, V.B.; Tamayo, P.; Casallas-Ojeda, Miguel; Siscar, E.; Fonoll, X.; Chimenos Ribera, Josep Ma.; Astals Garcia, Sergi
Phosphorus recovery is gaining importance due to its supply risk. Wastewater treatment plants (WWTPs) are sinks of phosphorus from municipal and industrial discharges, making them ideal sites for recovery. In WWTPs, the dosage of FeCl3 favours spontaneous formation of vivianite (Fe3(PO4)2⋅8H2O). The optimal Fe:P molar ratio and pH are 2.5:1 and 7–9, respectively. These conditions can achieve phosphate recoveries as vivianite of 70–90 % after the anaerobic digestion (AD) stage. Nonetheless, excessive addition of iron ions and/or vivianite formation in AD can hinder organic matter degradation and lower biogas yields. Anaerobic fermentation (AF) and seeding have enhanced phosphorus recovery yields. The former mobilises more phosphorus and iron into the soluble fraction, while the latter promotes larger crystal sizes by reducing the supersaturation demand. Vivianite precipitation is a promising technology for phosphorus recovery due to its potential applications in industry and agriculture, all while supporting the circular economy. This literature review provides a comprehensive overview of current knowledge on vivianite precipitation in WWTPs, including detection and quantification methods. It also identifies key disadvantages of vivianite formation in WWTPs and provides valuable recommendations for future research.
Honey geographical origin characterization and authentication based on spectrophotometric assays, physicochemical parameters and LC-MS/MS polyphenolic profiling
(MDPI, 2025-11) Mostoles, Danica; de Krijger, Fleur; Mara, Andrea; Sanna, Gavino; Saurina, Javier; Sentellas, Sonia; Núñez Burcio, Oscar
Honey is a highly consumed natural sweetener produced by honeybees from the nectar of plants, secretions of living parts of plants, or insect excretions. Its high value is due to its nutritional value and multiple benefits to human health. However, due to the diversity in geographical origins, the properties of honey can vary depending on the region of production, leading to discrepancies in honey pricing. Therefore, it is essential to examine these variations by analyzing several parameters in honey from diverse regions. In this work, honeys from 8 countries were characterized by measuring several physicochemical parameters and spectrophotometric assays aiming at geographical origin authentication. In addition, the polyphenolic profile of the samples was obtained by LC-LRMS. An acceptable discrimination of the samples was obtained when considering all variables altogether, with classification errors lower than 31.9%.
Nixtamalization of maize to reduce mycotoxin exposure: a human biomonitoring intervention study in Soweto, South Africa
(MDPI, 2025-10-25) Njobeh, Patrick B.; De Saeger, Sarah; Maris, Elias; Ndlangamandla, Palesa; Adelusi, Oluwasola A.; Akinmoladun, Oluwakamisi F.; Odukoya, Julianah O.; Fagbohun, Richard T.; Oyeyinka, Samson A.; Sekhejane, Palesa; Peró Gascón, Roger; De Boevre, Marthe; Croubels, Siska
Mycotoxin contamination is a global threat to food safety and human health, especially in regions facing food insecurity, such as Sub-Saharan Africa. This intervention study evaluates the effectiveness of nixtamalization, a traditional alkaline cooking method, in reducing mycotoxin levels in maize and corresponding urinary biomarkers of exposure. Forty adult healthy volunteers from an informal settlement in Kliptown, Soweto (South Africa), were randomly assigned to consume control maize or visibly moldy maize subjected to nixtamalization. Nixtamalization achieved a reduction of fumonisin B3 and deoxynivalenol (DON) to unquantifiable or undetectable levels in maize, while reducing fumonisin B1 (FB1), fumonisin B2, and zearalenone (ZEN) by 95%, 95%, and 89%, respectively. Aflatoxin B1 was unquantifiable before and eliminated after treatment. Biomarker analysis revealed that after consumption of either control or nixtamalized maize, urinary levels of FB1, ZEN, and its metabolites α- and β-zearalenol (α- and β-ZEL) did not show significant differences between groups (p>0.05). DON and tenuazonic acid levels were not affected by the intervention (p>0.05), with urinary detection frequencies remaining above 90%. These results demonstrate nixtamalization effectively lowers mycotoxin levels in maize, resulting in exposure levels comparable to control maize, and highlight human biomonitoring as a sensitive tool for evaluating food safety interventions.
Determination of dyes in candies in an analytical chemistry laboratory subject
(Omnia Science, 2025) Carrera, Laura; Serraïma, Dídac; Bagán Navarro, Héctor
The use of everyday life samples in laboratory subjects enhances motivation among students and, therefore, improves their learning outcomes. Candies are a common sample in students’ everyday life, which makes their dye content an interesting analyte to determine. Food dyes are usually found in candies to increase their attractiveness by providing a bright, intense colour. Their determination is interesting due to increasing concerns in society about the use of food additives. Therefore, this learning experience aims to quantify the content of food dyes in candy samples by UV-Vis spectrometry, taking advantage of their intrinsic colour. For this determination, students need to extract the dye from the candy, take the solution to an appropriate volume and measure the absorbance. Using the external calibration curve method, students calculate the dye concentration and then use this information to compare it with the limits established by the legislation. During this practical, students have optimized the experimental procedure, addressing the different problems that appeared. Also, several points were detected as good learning opportunities to discuss important aspects of the analytical chemistry. From this practical, students learn about the UV-Vis spectrometry technique, improve their practical skills of laboratory working and enhance their critical reasoning and information searching skills. This enables students to contextualize the analysis performed by understanding the importance of a concentration value obtained to solve a real problem and makes the acquired knowledge more significant, profound and constructive.
Acid dissociation constants in selected dipolar non-hydrogen-bond-donor solvents (IUPAC Technical Report)
(International Union of Pure and Applied Chemistry., 2025-12-01) Leito, Ivo; Kaljurand, Ivari; Piirsalu, Mare; Tshepelevitsh, Sofja; Zheng, Jonathan W.; Rosés Pascual, Martí; Gal, Jean-François
This compilation includes more than 9000 pK a values determined in seven dipolar non-hydrogen-bond-donor solvents {dimethyl sulfoxide, acetonitrile, N,N-dimethylformamide, pyridine, acetone, 4-methyl-1,3-dioxolan-2-one (propylene carbonate), oxolane (tetrahydrofuran)} for close to 5000 acids collected from around 800 original works published during the last 60 years. The data have been critically evaluated on the basis of defined quality criteria and depending on situation, kept as they were originally published, marked as doubtful/unreliable (around 2700 values) or corrected (around 2400 values). To enable automated processing and mining, the data are presented as a set of spreadsheets, together with structural codes (SMILES and InChI strings), compound class qualifiers, and comments. The document contains also comprehensive educational background information on the acid-base processes in non-aqueous media, as well as brief descriptions of the main measurement methods, with focus on the reliability of the data and sources of uncertainty. The full dataset is available at the permanent address https://doi.org/10.5281/zenodo.12608876.
LC-HRMS Fingerprinting and Chemometrics for the Characterization and Classification of Lotus Cultivars from Uruguay: A Study on Phenolic Composition
(Frontiers Media, 2025-08) Olivaro, Cristina; Núñez, Nerea; Basile, Patricia; Mederos, América; Reyno, Rafael; Saurina, Javier; Núñez Burcio, Oscar
Introduction: The Lotus genus, part of the legume family, comprises over 180 species distributed across diverse ecosystems worldwide. Its broad genetic diversity enables adaptation to various environmental conditions and represents a valuable resource for breeding programs targeting key agronomic traits. One of the most attractive features of Lotus species is the presence of condensed tannins in the forage, which, in ruminants, help prevent bloat, exhibit antiparasitic properties, enhance the absorption of non-ammonia nitrogen compounds, and reduce greenhouse gas emissions. Aims and methods: This study aimed to develop a UHPLC-HRMS method for classifying ten Lotus cultivars produced in Uruguay using a non-targeted metabolomic fingerprinting approach. Five cultivars belong to Lotus corniculatus, three to Lotus uliginosus, and two are interspecific hybrids. The analysis focused on phenolic compound-rich fingerprints. Principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) were used for data exploration and classification, and to identify key phenolic compounds with high discriminant potential. Finally, cultivar-specific polyphenolic compounds were tentatively identified based on chromatographic and high-resolution mass spectrometry (HRMS/MS) data obtained from all cultivars. Results: When defining four classes (L. uliginosus, L. corniculatus, and the two hybrids), the optimal PLS-DA model required six latent variables and achieved 100% classification accuracy, with both sensitivity and specificity reaching 100%. Additional PLS-DA models were developed to assess intra-species discrimination among the 3 L. uliginosus and 5 L. corniculatus cultivars, with varying degrees of separation observed. In each PLS-DA model, VIP loadings scores allowed the selection of the most discriminant phenolic compounds for each class under study. A total of 105 compounds, including phenolic acids, flavonols, flavan-3-ols, proanthocyanidins, and organic acids, were tentatively identified by analyzing all cultivars.
An FIA-MS Method for Rapid Coffee Adulteration Detection: A Comparative Study with a Non-Targeted LC-MS Approach
(MDPI, 2025-08) Núñez Burcio, Oscar; Núñez, Nerea; Saurina, Javier
Coffee adulteration is a growing concern in the food industry due to economic and quality implications. This study evaluates a rapid, non-targeted fingerprinting method based on flow injection analysis–mass spectrometry (FIA-MS) for detecting common coffee adulterants. A total of 119 samples were analyzed, including 43 coffee samples and 76 samples of common coffee adulterants (16 chicory, 10 barley, and 50 flour samples). FIA-MS combined with chemometric analysis allowed for the classification of pure and adulterated coffee samples with over 95% accuracy. Compared to LC-MS, the FIA-MS method showed a similar performance while offering significantly faster analysis and lower solvent consumption, making it a practical and sustainable option for high-throughput screening. For PLS regression studies, calibration and prediction errors were consistently below 0.91% and 11.7%, respectively. Furthermore, the methodology was compared with a non-targeted LC-MS approach, showing an excellent performance.
Cobalt ferrite magnetic nanoparticles as stirring actuators to improve UV–Vis spectroelectrochemical measurements in normal reflection mode.
(Springer Verlag, 2025-08-01) Cutillo‑Foraster, Alessandra; Özbek, Nurhayat; Otero‑de-Muller, Lluís; Bastos-Arrieta, Julio; Serrano i Plana, Núria; Díaz Cruz, José Manuel
Spectroelectrochemical (SEC) measurements using UV–Vis radiation in normal reflection mode (or normal configuration)are less sensitive than parallel approaches, since the volume of sample monitored has a much lower proportion of the diffusionlayer created by the electrochemical processes, i.e., the region where relevant optical changes take place. In contrast,the normal configuration is more robust and reproducible and, as of today, is the only commercially available. This workpresents a strategy to enhance normal reflection SEC measurements of Fe(III)/(II)-orthophenanthroline system using ascreen-printed carbon electrode (SPCE), improving competitiveness with parallel designs. This method required the designof a new measuring cell based on the geometry of the commercial one, but replacing the eight magnets by a non-magneticclosing system. The developed approach involves adding cobalt ferrite magnetic nanoparticles (CoFe2O4 MNPs) to theanalyte solution and coupling the SEC cell to a conventional magnetic stirrer. The resulting nanostirring, driven by MNPsmovement, enhances mass transport toward the electrode. This accelerates diffusion layer renewal, leading to a noticeableincrease of both electrochemical and optical signals.

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Articles publicats en revistes (Enginyeria Química i Química Analítica)

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El CRAI romandrà tancat del 24 de desembre de 2025 al 6 de gener de 2026. La validació de documents es reprendrà a partir del 7 de gener de 2026.

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