Articles publicats en revistes (Enginyeria Química i Química Analítica)

URI permanent per a aquesta col·leccióhttps://hdl.handle.net/2445/20401

Estadístiques

Examinar

Mostrant 1 - 20 de 773

An expanded framework for Swab Touch Spray-Mass Spectrometry towards the detection of allergenic protein residues on food preparation surfaces
(Elsevier B.V., 2025-02-19) Toma, Lorenzo; Piergiovanni, Maurizio; Gentili, Silvia; Mattarozzi, Monica; Careri, Maria; Moyano Morcillo, Encarnación
Background Ambient Mass Spectrometry (AMS) encompasses a group of techniques that have emerged as powerful strategies for direct, in-situ and high-throughput analysis, also in compliance with the principles of green analytical chemistry. Swab Touch Spray-Mass Spectrometry (Swab TS-MS) is a home-made AMS technique that involves the use of a medical swab as sampling tool and electrospray probe. To date, Swab TS-MS has been applied only for the analysis of small molecules, especially in forensic and medical fields, leaving the analysis of peptides and proteins still unexplored. Results In the present study, the application framework of Swab TS-MS was expanded towards the detection of proteins, focusing on residues of allergenic ingredients as contaminants of food preparation surfaces. Lysozyme from chicken egg white was selected as case study of allergenic protein. Since none of the experimental conditions explored allowed the detection of intact lysozyme, a bottom-up procedure based on tryptic digestion for lysozyme detection by Swab TS-MS, operating in MS/high resolution (HR)MS tandem mode, was investigated. In parallel, liquid chromatography-tandem mass spectrometry was used to develop and characterize an in-situ digestion/swabbing strategy, allowing to reach a LOD value of 0.003 μg/cm2 of egg white powder consistent with that of lateral flow immunoassay technique. Finally, the developed in-situ digestion/swabbing procedure was coupled to the Swab TS-MS/HRMS method, permitting the direct analysis of egg white powder residues on stainless steel surfaces, reaching a LOD of 68 μg/cm2 egg white powder, corresponding to 2.4 μg/cm2 of lysozyme. Significance This study should be intended as a first step for the application of Swab TS-MS technique in protein analysis: the developed in-situ digestion and sampling strategy suitable for Swab TS-MS direct analysis of food allergen has a valuable impact towards the availability of MS-based multiplexed detection tool useful for the development of efficient surface cleaning procedures.
Prenatal exposure to persistent organic pollutants and sex-specific neonatal outcomes in the ENVIRONAGE birth cohort.
(Elsevier, 2026-02-15) De Saeger, Sarah; Raes, Jeroen; Nawrot, Tim S.; Vanhaecke, Lynn; Covaci, Adrian; Cseresznye, Adam; Ouden, Fatima den; Engelen, Liesa; Maris, Elias; Ait Bamai, Yu; Paepe, Ellen De; Poma, Giulia; Derrien, Muriel; Vich Vila, Arnau; Hemeryck, Lieselot Y.; Peró Gascón, Roger
Early-life exposure to environmental contaminants, such as endocrine disrupting persistent organic pollutants (POPs), including polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and organochlorine pesticides (OCPs), is linked to adverse neonatal outcomes. However, the sex-specific effects of POP mixtures and the potential mediating roles of biological pathways, such as inflammation, remain insufficiently understood. This study aimed to investigate these aspects within the ENVIRONAGE birth cohort. The study population consisted of newborns (n = 402) from the ENVIRONAGE birth cohort, of which cord plasma levels of POPs were quantified using GC-ECNI/MS. Neonatal birth outcomes were derived from anthropometric measurements obtained at birth and via questionnaires completed postpartum. Among the 28 targeted POPs, nine were found in more than 50 % of the samples with CB 170, 180 and 153 detected in over 98 % of them. In single-pollutant models, several PCBs were inversely associated with ponderal index, while CB 118 was positively associated with head circumference in males (FDR-adjusted p < 0.05). Weighted Quantile Sum (WQS) regression revealed that in males, the POP mixture was inversely associated with birth weight (β = −141.21, p < 0.05) and ponderal index (β = −0.11, p < 0.01) and positively associated with head circumference (β = 0.53, p < 0.01) and the odds of preterm birth (OR = 2.91, p < 0.05). Conversely, among females, the POP mixture was associated with reduced odds of small-for-gestational-age (SGA) (OR = 0.21, p < 0.05) and below normal APGAR scores (OR = 0.39, p < 0.05). Mediation analysis indicated that the association between p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) and reduced birth weight/length was significantly mediated by eosinophil levels.
Zwitterionic-hydrophilic interaction capillary liquid chromatography coupled to tandem mass spectrometry for the characterization of human alpha-acid-glycoprotein N-glycan isomers
(Elsevier B.V., 2017-10-23) Mancera Arteu, Montserrat; Giménez López, Estela; Barbosa Torralbo, José; Peracaula, R.; Sanz Nebot, María Victoria
In this work, a μZIC-HILIC-MS/MS methodology was established in negative ion mode for the characterization of glycan isomers. The possibility to separate the glycan isomers by the μZIC-HILIC strategy coupled to a high resolution tandem mass spectrometry detection permitted us to obtain valuable information about each glycan structure. The most important diagnostic ion fragments previously described to characterize structural features of glycans, were evaluated in this study using hAGP as model glycoprotein. The assignation of hAGP glycan isomers performed in our previous work using the GRIL strategy in combination with exoglycosidase digestion [1] was used in this paper to confirm or discard some ion fragments reported in the literature and delve into the structural characterization of glycan isomers. Sialic acid as well as fucose linkage-type glycan isomers were assigned using this approach and daughter ions with higher diagnostic value were determined. The location of α2-3/α2-6 sialic acids on antennas and a deeper characterization of several highly sialylated tri- and tetraantennary glycans was also possible using the established MS/MS method. Moreover, relying on the characterization performed in Ref. [1], core and antenna fucosylation were differentiated in this work using specific ion fragments obtained in the tandem mass spectra. This methodology was also applied to hAGP purified from control and pathological serum samples, which corroborated its robustness and its potential for finding novel glycan-based biomarkers in patho-glycomic studies.
Fotoionización a presión atmosférica para el análisis de compuestos halogenados mediante Cromatografía de gases-espectrometría de masas
(Sociedad Española de Química Analítica (SEQA), 2023-12) Moyano Morcillo, Encarnación; Ayala Cabrera, Juan Francisco; Santos Vicente, Francisco Javier
Durante años, la determinación de una gran variedad de contaminantes orgánicos persistentes halogenados se ha llevado a cabo mediante el acoplamiento GC-MS, utilizando generalmente técnicas de ionización de alto vacío, com la ionización electrónica (EI) o la ionización química (CI). Sin embargo, algunos de estos compuestos presentan problemas con estas técnicas de ionización, como la elevada fragmentación que produce la EI o la baja eficacia de ionización en CI. Para solventar todos estos problemas y mejorar la capacidad de detección se han incorporado en los equipos GC-MS de nuevas fuentes, como la ionización química a presión atmosférica (APCI) y la fotoionización a presión atmósferica (APPI), que producen una ionización suave que permite preservar las moléculas originales generando iones moleculares o iones resultado de su protonación y desprotonación. En este trabajo se pretende dar una descripción de los fundamentos de APPI para GC-MS y mostrar algunas de las aplicaciones desarrolladas utilizando GC-APPI-HRMS para el análisis de diferentes familias de contaminantes halogenados en muestras medioambientales.
Identification and characterization of isomeric N-glycans of human alfa-acid-glycoprotein by stable isotope labelling and ZIC-HILIC-MS in combination with exoglycosidase digestion
(Elsevier B.V., 2016) Mancera Arteu, Montserrat; Giménez López, Estela; Barbosa Torralbo, José; Sanz Nebot, María Victoria
In this study, a ZIC-HILIC-MS methodology for the analysis of N-glycan isomers was optimized to obtain greater detection sensitivity and thus identify more glycan structures in hAGP. In a second step, this method was combined with glycan reductive isotope labelling (GRIL) through [12C6]/[13C6]-aniline and exoglycosidase digestion to characterize the different glycan isomers. The GRIL method allows the peak areas resulting from two different labelled samples to be compared, since neither retention time shifts nor variations in the ionization of glycans between these samples are obtained. First, sialic acid linkage assignations were performed for most hAGP glycan isomers with α2-3 sialidase digestion. Bi-, tri- and tetraantennary glycan isomers with different terminal sialic acid linkages to galactose (α2-3 or α2-6) were assigned, and the potential of this technique for the structural characterization of isobaric isomers was therefore demonstrated. Furthermore, fucose linkage isomers of hAGP glycans were also characterized using this isotope-labelling approach in combination with α1-3,4 fucosidase and β1-4 galactosidase digestion. α1-3 antennary fucoses and α1-6 core fucosylation were detected in hAGP fucosylated glycans. These established methodologies can be extremely useful for patho-glycomic studies to characterize glycoproteins of biomedical interest and find novel glycan isomers that could be used as biomarkers in cancer research.
Exploring metal-organic framework-coated blades for direct and high-throughput screening analysis of complex biological matrices
(American Chemical Society, 2025-08-20) Negrín-Santamaría, Isaac; Trujillo-Rodríguez, María J.; Moyano Morcillo, Encarnación; Ayala, Juan A; Zuloaga, Olatz; Pasán, Jorge; Pino, Verónica; Ayala Cabrera, Juan Francisco
Ambient ionization mass spectrometry techniques (AIMS) have become an emerging approach over the last years due to their simplicity, permitting high-throughput sample analysis by direct coupling to mass spectrometry while ensuring short analysis times. Among AIMS techniques, coated-blade spray (CBS) has stood out as it ensures a significant enhancement of overall sensitivity, undoubtedly useful for human biofluid analysis. In parallel, the incorporation of advanced smart materials, such as metal-organic frameworks (MOFs), into analytical devices is rising due to their outstanding ability to trap efficiently target analytes such as industrial chemicals with diverse functionalities and polarities. This study integrates neat MOFs in CBS devices, without the need of any composite or additional materials, through a simple and mild strategy, and their use in the determination of xenobiotics present in human urine samples. Moreover, a suspect screening workflow by high-resolution mass spectrometry (HRMS) has been developed for the first time to extend the chemical coverage of AIMS techniques. This simultaneous approach ensures a proper analytical quality performance, achieving limits of quantification (LOQs) down to 0.1 ng·mL^-1 despite only requiring 8 min for the entire procedure.
Resolution of overlapping optical signals: Dual sensing vs chemometrics
(Elsevier B.V., 2025-11-01) Pérez Ràfols, Clara; Serrano i Plana, Núria; Fuguet i Jordà, Elisabet; Díaz Cruz, José Manuel; Rafols Llach, Clara
Signal overlapping is a common issue that often prevents the full implementation of UV–Vis dip probes in on-site analysis, even in the case of relatively simple chemical systems. In this work, two strategies for the resolution of optical signals without the need of sample treatment are compared: (i) dual sensing based on the combination of optical and electrochemical signals; and (ii) data treatment of optical signal by means of chemometrics. For this purpose, two different systems were evaluated. The first one comprised pyrocatechol (CC) and isonicotinamide (INAM) as an example of a system containing only one electroactive species and the second one contained CC and isoniazide (INH) as an example of a chemical system with two electroactive compounds. Both strategies proved successful in the resolution of the optical overlapping in static conditions (i.e., non-stirred solutions), with slopes in the range of 0.88–1.08 and R2 values higher than 0.989 for the representation of predicted vs expected concentration values for both chemical systems. Nevertheless, only chemometrics was able to resolve both systems in dynamic conditions (slopes in the range of 0.873–1.10 and R2 values higher than 0.99), as the increased transport of INH significantly affected electrochemical measurements. Dual sensing was also successful in the resolution of CC and INAM (slopes in the range of 1.014–1.035 and R2 values higher than 0.99), proving even better than chemometric analysis, particularly in the region of lower CC concentrations.
Characterization of HPLC columns: a comparison of Tanaka and Abraham methods
(Elsevier B.V., 2025-09-12) Subirats i Vila, Xavier; Rosés Pascual, Martí
Characterization of the selectivity of HPLC columns is an essential need in many chromatographic development methods. Different tests and procedures have been developed for this purpose. In this paper, we analyze two of the most used methods, the Tanaka tests and the Abraham solvation parameter model, and compare the information obtained for neutral solutes in two columns with different stationary phases: a C18 and a CN columns. The Tanaka tests use pairs of solutes to characterize column selectivities caused by hydrophobicity, shape, and hydrogen bonding interactions of neutral solutes with the mobile and the stationary phases. Abraham model provides information on the selectivities caused by the interactions of cavity creation, hydrogen bond basicity, hydrogen bond acidity, and dipolarity/polarizability of the solute with the mobile and stationary phases from the retention of a relatively larger set of neutral solutes. Analysis of the solute’s characteristics and retention in the two columns shows that the Tanaka selectivity for solute hydrophobicity is equivalent to the selectivity obtained from the Abraham term for the differences in the cavity formation of the solute in mobile and stationary phases. Abraham model does not consider shape selectivity, but the apparent shape selectivity measured by the Tanaka test does not consider the influence on retention/selectivity caused by differences in the size, dipolarity/polarizability, and hydrogen bonding capabilities of the test solutes. If these differences are taken into account, the differences in the selectivity coefficient obtained for steric interaction may be considerable. Tanaka selectivity for hydrogen bonding is a mixing of selectivities for hydrogen bonding from solute to the chromatographic phases (column hydrogen bond basicity) and from the phases to the solute (column hydrogen bond acidity). The Abraham method differentiates between the two types of selectivities: hydrogen bond acidity and hydrogen bond basicity. Additionally, Abraham method provides information on the dipolarity and polarizability selectivities. Finally, new selectivity coefficients are proposed for the interactions of the Abraham model; solute cavity formation (or hydrophobicity), hydrogen bond basicity, hydrogen bond acidity, dipolarity/polarizability, and excess polarizability.
Progress on the Link between Nutrient Availability and Toxin Production by Ostreopsis cf. ovata: Field and Laboratory Experiments
(MDPI, 2023-03) Medina-Pérez, Noemí Inmaculada; Cerdán-García, Elena; Rubió, Francesc; Viure, Laia; Estrada, Marta; Moyano Morcillo, Encarnación
This study aimed to improve the understanding of the nutrient modulation of Ostreopsis cf. ovata toxin content. During the 2018 natural bloom in the NW Mediterranean, the total toxin content (up to ca. 57.6 ± 7.0 pg toxin cell−1) varied markedly. The highest values often coincided with elevated O. cf. ovata cell abundance and with low inorganic nutrient concentrations. The first culture experiment with a strain isolated from that bloom showed that cell toxin content was higher in the stationary than in the exponential phase of the cultures; phosphate- and nitrate-deficient cells exhibited similar cell toxin variability patterns. The second experiment with different conditions of nitrogen concentration and source (nitrate, urea, ammonium, and fertilizer) presented the highest cellular toxin content in the high-nitrogen cultures; among these, urea induced a significantly lower cellular toxin content than the other nutrient sources. Under both high- and low-nitrogen concentrations, cell toxin content was also higher in the stationary than in the exponential phase. The toxin profile of the field and cultured cells included ovatoxin (OVTX) analogues -a to -g and isobaric PLTX (isoPLTX). OVTX-a and -b were dominant while OVTX-f, -g, and isoPLTX contributed less than 1-2%. Overall, the data suggest that although nutrients determine the intensity of the O. cf. ovata bloom, the relationship of major nutrient concentrations, sources and stoichiometry with cellular toxin production is not straightforward.
A novel methodology for the determination of neutral perfluoroalkyl and polyfluoroalkyl substances in water by gas chromatographyatmospheric pressure photoionisation-high resolution mass spectrometry
(Elsevier B.V., 2020-03-01) Ayala Cabrera, Juan Francisco; Contreras Llin, Albert; Moyano Morcillo, Encarnación; Santos Vicente, Francisco Javier
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 determination of neutral perfluoroalkyl and polyfluoroalkyl substances (PFASs) in water samples. The method includes fluorotelomer olefins (FTOs), fluorotelomer alcohols (FTOHs), fluoroctanesulfonamides (FOSAs) and sulfonamido-ethanols (FOSEs). The feasibility of the GC-APPI interface for the ionisation of the target compounds was evaluated, achieving the best results using negative-ion dopant-assisted ionisation with acetone and a source and capillary temperatures of 225 oC and 175 oC, respectively. Under optimal conditions, FTOs and FTOHs mass spectra showed intense in-source CID fragment ions from the fluoroalkyl chain but also the superoxide [M+O2]-· adduct ion. For FOSAs, [M-H]- was the main ion generated, while FOSEs mass spectra showed fragment ions corresponding to the different cleavages of the functional group. The high ionisation efficiency achieved with the GC-APPI interface provided limits of the detection lower than those obtained using traditional GC-MS ionisation techniques, with a high sensitivity, selectivity and precision. For water analysis, a fast and simple HS-SPME procedure was developed, avoiding evaporation steps, which could lead to the loss of the most volatile compounds. The developed HS-SPME GC-APPI-HRMS method showed a good analytical performance for the analysis of river water samples, providing very low limits of detection (0.02e15 ng L 1), good repeatability (RSD < 11%) and trueness (relative error < 12%).
Chemical exposure in childhood: A. study on organophosphate flame retardants and plasticizers
(Elsevier, 2026-01-01) Proost, Sebastian; Vich Vila, Arnau; Raes, Jeroen; Vanhaecke, Lynn; De Boevre, Marthe; De Saeger, Sarah; Nawrot, Tim S.; Poma, Giulia; Covaci, Adrian; Ouden, Fatima den; Cseresznye, Adam; Engelen, Liesa; Maris, Elias; Bosschaerts, Stijn; Gys, Celine; Cleys, Paulien; Ait Bamai, Yu; Peró Gascón, Roger; Hemeryck, Lieselot Y.; Paepe, Ellen De
Humans are exposed daily to contaminants such as organophosphorus flame retardants (PFRs), legacy plasticizers (LPs), and alternative plasticizers (APs). To date, most biomonitoring studies in children have only focused on analysis of LP metabolites and a subset of PFRs and APs. This study investigated exposure to multiple PFRs, LPs and APs in the ENVIRONAGE birth cohort quantifying 13 PFR metabolites in 655 urine samples, while we measured 8 LP and 13 AP metabolites in urine of 328 children. For PFRs, more than 50% of children were exposed to TNBP, TPHP, TDCIPP, TCIPP and EHDPHP. More than 93% of children were exposed to the measured LPs (DEP, DiBP, DnBP, BBzP and DEHP), while for APs more than 50% of children showed exposure to DEHA, DEHTP, DINCH and DIDP. Concentrations of PFR metabolites were higher in summer, while the presence of a pet in the house was associated with higher LP metabolite concentrations. Risk characterization ratios (RCRs) for single compounds and hazard indices (HIs) for compound classes suggested no risk for adverse health effects due to PFR exposure. For LPs, two children showed a HI above 1, while for APs, ten children had a HI above 1. The results indicate widespread exposure to PFRs and plasticizers, with most children being exposed to levels that are considered safe. However, the current study confirms a shift in exposure from LPs to APs, implying the need for further research on exposure to multiple APs in future studies.
Development and validation of an LC-MS/MS method for the simultaneous detection of urinary inflammatory biomarkers in a Flemish birth cohort
(Elsevier B.V., 2026-01-15) Raes, Jeroen; Vanhaecke, Lynn; Nawrot, Tim S.; Covaci, Adrian; Ouden, Fatima den; Cseresznye, Adam; Engelen, Liesa; Maris, Elias; Paepe, Ellen De; Poma, Giulia; Proost, Sebastian; Vich Vila, Arnau; Hemeryck, Lieselot Y.; Peró Gascón, Roger; De Saeger, Sarah
Chronic inflammation is a significant contributor to various diseases but its assessment via blood sampling presents challenges, particularly in children. The evaluation of urinary biomarkers, including 3-bromotyrosine (Bty), 3-chlorotyrosine (Cty) and leukotriene E4 (LTE4), offers a non-invasive alternative. This study presents the optimization and validation of a sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the simultaneous quantification of Bty, Cty and LTE4 in urine. Under optimized conditions, sample preparation was based on SPE using Oasis MAX cartridges, followed by LC-MS/MS analysis. Method performance was validated using the ICH 10 guidelines, resulting in satisfactory results for all analytes in terms of recovery, linearity, limits of quantification, precision and accuracy. Recovery rates ranged from 82% to 97%, while matrix effects were observed within the range of -11% to 26%. Linear range spanned from 0.08 to 20 ng/mL for the three analytes. Application to 332 urine samples from the ENVIRONAGE birth cohort (Belgium), comprising of children aged 4–11 years, revealed detection frequencies of 18% for LTE4, 19% for Cty and 50% for Bty. Notably, creatinine-corrected Cty and LTE4 exhibited statistically significant Spearman correlations with established systemic inflammation markers. Specifically, Cty was positively correlated with absolute monocyte count (ρ = 0.53, p < 0.05), while LTE4 showed a positive correlation with relative eosinophil levels (ρ = 0.46, p < 0.05) and a negative correlation with the relative neutrophil levels (ρ = -0.56, p < 0.01). These results highlight the validated method as a valuable tool for investigating distinct inflammatory pathways in epidemiological settings and clinical research.
Towards biomimetic electrochromatography: Fast method for the Abraham's characterization of solute-solvent interactions in micellar and microemulsion electrokinetic systems
(Elsevier B.V., 2025-09-13) Idrees, Rabia; Subirats i Vila, Xavier; Amézqueta, Susana; Rosés Pascual, Martí
This study presents a fast method for the characterization of solute-solvent interactions in micellar and microemulsion electrokinetic chromatography based on the linear solvation energy relationships proposed by Abraham. The magnitude of the different types of interactions between solutes and chromatographic phases is determined from the differences in migration observed for pairs of solutes, and the effect of the different cohesion of the dispersed phase and the dispersive medium is determined from the injection of a mixture of homologous compounds, using in all injections nonanophenone as dispersed phase marker. For excess polarizability interactions (e), the compounds 8-hydroxyquinoline and 1,2-dimethoxybenzene are used. The dipolarity/polarizability coefficient (s) is assessed with 1,4- or 1,2-dicyanobenzene and 2-methylbenzaldehyde. To evaluate the solute hydrogen bond acceptor capacity (a), 3-ethoxyphenol and 2-chloroacetophenone are employed, and the hydrogen bond donor capacity (b) is characterized using 2,3,5,6-tetramethylpyrazine and 2,6-dimethylanisole. Finally, the cavity term (v) is determined using a mixture of n-alkyl phenone homologues in the range of acetophenone to heptanophenone, depending on the nature of the electrokinetic system. This fast approach allows for results comparable to the conventional methodology, which is based on the injection of a relatively large number of solutes and subsequent analysis using multiple linear regressions, but significantly reducing the time and resources invested in the characterization of electrokinetic chromatography systems. This novel method was assayed with micellar solutions prepared from bile salts (SC, SDC), anionic surfactants (SDS, LDS), and cationic surfactants (CTAB, TTAB), and microemulsions consisting of heptane, 1-butanol, and surfactants (SDS, SC, and TTAB) at different concentrations and pH values. Provided that electrokinetic chromatography has a high potential mimicking biological systems due to the availability of surfactants and cosurfactants of different natures and the wide operational pH range, this study aims to contribute to the development of biomimetic chromatography by proposing a screening method based on the Abraham’s solvation parameter model, widely used in the characterization of biological systems.
Analysis of O-glycopeptides by acetone enrichment and capillary electrophoresis-mass spectrometry
(American Chemical Society, 2017-11-03) Mancera Arteu, Montserrat; Giménez López, Estela; Benavente Moreno, Fernando J. (Julián); Barbosa Torralbo, José; Sanz Nebot, María Victoria
Acetone precipitation was evaluated as a rapid, simple, low-cost, and efficient method for the selective purification of O-glycopeptides from enzymatic digests of glycoproteins. Ovalbumin (OVA), human and bovine α1-acid glycoprotein (hAGP and bAGP), human apolipoprotein C–III (APO-C3), and recombinant human erythropoietin (rhEPO) were used to obtain enzymatic digests with a broad and varied set of peptides, N-glycopeptides, and O-glycopeptides. After digestion and before capillary electrophoresis mass spectrometry (CE-MS) analysis, the amount of ice-cold acetone added to the digests was optimized to maximize recoveries of O-glycopeptides. Furthermore, the different behavior of peptides, N- and O-glycopeptides was explained by studying with multivariate data analysis methods the influence of several physicochemical parameters and properties related to their composition and structure. Principal component analysis (PCA) and, afterward, partial least-squares discriminant analysis (PLS-DA) were used to identify the most significant variables and their importance to differentiate between peptides, N-glycopeptides and O-glycopeptides, or within these classes. This information was useful to understand precipitation of these compounds after addition of acetone and for the selection of the optimal conditions for purification of specific O-glycopeptide biomarkers. Special attention was paid to O126-glycopeptide glycoforms of rhEPO because of their applicability in biopharmaceutical quality control and doping analysis.
RBD-Based ELISA and Luminex Predict Anti-SARS-CoV-2 Surrogate-Neutralizing Activity in Two Longitudinal Cohorts of German and Spanish Health Care Workers
(American Society for Microbiology, 2023-02-14) Aguilar, Ruth; Li, Xue; Crowell, Claudia S.; Burrell, Teresa; Vidal, Marta; Rubio, Rocío; Jiménez, Alfons; Hernández-Luis, Pablo; Hofmann, Dieter; Mijočević, Hrvoje; Jeske, Samuel; Christa, Catharina; D'Ippolito, Elvira; Lingor, Paul; Knolle, Percy A; Roggendorf, Hedwig; Priller, Alina; Yazici, Sarah; Carolis, Carlo; Mayor Aparicio, Alfredo Gabriel; Schreiner, Patrik; Poppert, Holger; Beyer, Henriette; Schambeck, Sophia E.; Izquierdo Lázaro, Luis; Tortajada, Marta; Angulo Aguado, Ana; Soutschek, Sophia E.; Engel Rocamora, Pablo; Garcia-Basteiro Alberto L.; Busch, Dirk H; Moncunill Piñas, Gemma; Protzer, Ulrike; Dobaño, Carlota, 1969- ; Gerhard, Markus
The ability of antibodies to neutralize severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an important correlate of protection. For routine evaluation of protection, however, a simple and cost-efficient anti-SARS-CoV-2 serological assay predictive of serum neutralizing activity is needed. We analyzed clinical epidemiological data and blood samples from two cohorts of health care workers in Barcelona and Munich to compare several immunological readouts for evaluating antibody levels that could be surrogates of neutralizing activity. We measured IgG levels against SARS-CoV-2 spike protein (S), its S2 subunit, the S1 receptor binding domain (RBD), and the full length and C terminus of nucleocapsid (N) protein by Luminex, and against RBD by enzyme-linked immunosorbent assay (ELISA), and assessed those as predictors of plasma surrogate-neutralizing activity measured by a flow cytometry assay. In addition, we determined the clinical and demographic factors affecting plasma surrogate-neutralizing capacity. Both cohorts showed a high positive correlation between IgG levels to S antigen, especially to RBD, and the levels of plasma surrogate-neutralizing activity, suggesting RBD IgG as a good correlate of plasma neutralizing activity. Symptomatic infection, with symptoms such as loss of taste, dyspnea, rigors, fever and fatigue, was positively associated with anti-RBD IgG positivity by ELISA and Luminex, and with plasma surrogate-neutralizing activity. Our serological assays allow for the prediction of serum neutralization activity without the cost, hazards, time, and expertise needed for surrogate or conventional neutralization assays. Once a cutoff is established, these relatively simple high-throughput antibody assays will provide a fast and cost-effective method of assessing levels of protection from SARS-CoV-2 infection. IMPORTANCE Neutralizing antibody titers are the best correlate of protection against SARS-CoV-2. However, current tests to measure plasma or serum neutralizing activity do not allow high-throughput screening at the population level. Serological tests could be an alternative if they are proved to be good predictors of plasma neutralizing activity. In this study, we analyzed the SARS-CoV-2 serological profiles of two cohorts of health care workers by applying Luminex and ELISA in-house serological assays. Correlations of both serological tests were assessed between them and with a flow cytometry assay to determine plasma surrogate-neutralizing activity. Both assays showed a high positive correlation between IgG levels to S antigens, especially RBD, and the levels of plasma surrogate-neutralizing activity. This result suggests IgG to RBD as a good correlate of plasma surrogate-neutralizing activity and indicates that serology of IgG to RBD could be used to assess levels of protection from SARS-CoV-2 infection.
Pulsed amperometric detection: Extending the applicability of HPLC to substances with two-step redox processes.
(Elsevier B.V., 2025-11-05) Pages-Rebull, Josep; Pérez Ràfols, Clara; Serrano i Plana, Núria; Díaz Cruz, José Manuel
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 active substances may be detected with the classical amperometric detection that involves the application of a single potential. For instance, in flow conditions, the main biomarkers of cinnamon (eugenol, coumarin, cinnamaldehyde and cinnamic acid) require an oxidation step prior to their amperometric detection. Pulsed amperometric detection (PAD) is proposed to address the electrochemical determination of substances with such complex redox behaviour in flow conditions because it allows the application of multiple potential steps that mimic the sequential stages that would be performed in static voltammetric measurements. PAD waveform has been optimized resulting in two scenarios (tox>> tred and tox <
Modeling nitrogen recovery and water transport in gas-permeable membranes
(Elsevier, 2025-02) Da Silva, C.; Serra Toro, Andreu; Pelizzaro, V.; Valentino, Francesco; Astals Garcia, Sergi; Mas i Pujadas, Francesc; Dosta Parras, Joan
This study presents a new modeling approach for nitrogen recovery in gas-permeable membrane (GPM) con- tactors, including both ammonia and water transport dynamics. A distinct feature of the model is its capacity to model water transport across the membrane, which has been overlooked in most publications. Osmotic pressure differences are used to predict the behavior of ammonia and water transport in the GPM contactor. Experiments carried out to develop, test and calibrate the model examined the dynamics of ammonia and water transport through the GPM contactor at various nitrogen concentrations. Specifically, the GPM contactor was tested for nitrogen recovery from high-strength synthetic wastewaters (2.4–10.6 g N/L) at 35 ◦C and at pH 9. The initial volume of the trapping solution (diluted H2SO4) was 10 times lower than that of the synthetic wastewater, aiming to concentrate the recovered nitrogen. The estimated ammonia transport constant (Km) ranged between (1.2 - 2.1)⋅10–6 m/s and water transport constant Kw between (2.8 - 8.2)⋅10–10 m/(s bar). Numerical determi- nation of the model parameters revealed high R2 values, demonstrating strong agreement with experimental data.
Scintillating iron imprinted polymers (Sc-Fe-IIP): Novel material for 55 Fe selective recognition
(Elsevier B.V., 2025) Giménez Guerra, Isaac; Bagán Navarro, Héctor; Tarancón, A.
In the coming years, numerous nuclear power plants are expected to reach the end of their operational lifespans, leading to a substantial increase in the demand for analyses during the decommissioning process. Of particular concern is 55Fe, a fission product originating from neutron activation of stable iron. The conventional methods for determining 55Fe using liquid scintillation are known for being time-consuming, complex, and involving multiple steps to eliminate interferences. In this work, the first scintillating imprinted polymer for 55Fe has been developed (Sc-Fe-IIP). Several tests have been conducted to define the polymerization procedure, the components of the polymer, and their proportions, making it possible to combine selective retention and scintillation capabilities for 55Fe determination in one material. The optimum Sc-Fe-IIP is composed of styrene, divinylbenzene, and vinyl phosphonic acid, together with a complex of Fe with acrylic acid and scintillation fluorescence solutes. The iron capacity is up to 17 mg per gram of Sc-Fe-IIP, and the selectivity is 95 %, with reduced retention of copper (4 %) and no retention of nickel or cobalt. Regarding scintillation capabilities, the Sc-Fe-IIP showed a detection efficiency of 4.90 %.
Rheological study of pullulan-pectin mixtures to prepare gel beads using the drip method and evaluation as gallic acid release systems.
(Elsevier B.V., 2025-01-16) Santamaría Hernández, Esther; Maestro Garriga, Alicia; Chowdhury, Sultana; Vílchez Maldonado, Susana; González, Carlos
Pullulan (PUL) is a polysaccharide that can form gels using sodium trimetaphosphate (STMP). This gelationoccurs at basic pH and has very slow kinetics, so that gel beads cannot be formed by the dripping method sincePUL diffuses towards the medium before it can gel. To accelerate the gelling process and be able to obtainpullulan beads, hybrid gels were formed, mixing PUL with pectin (PEC). Then, STMP was added to gel the PUL,and Ca2+ was separately added to gel the PEC for comparative purposes. In both cases, the minimum concentrationof gelling agent to obtain a gel was reduced by 90%. The gelation of these STMP-hybrid gels waspractically instantaneous, thus allowing the production of beads by dripping the polysaccharide solution in anaqueous STMP solution. The PUL-PEC gels were characterized by FT-IR, which confirmed the junction of thePUL-PEC molecules by hydrogen bonds in the gel, as well as de-esterification of methoxyl groups and ionizationof acid groups. The addition of PEC did not affect the swelling degree of the PUL gel, probably since it wasgoverned by STMP-PUL junctions, but it increased the water holding capacity, which was related to the presenceof more -OH groups to retain water by hydrogen bonds. PUL-PEC beads loaded with gallic acid were successfullyprepared by the dripping method to evaluate their suitability as delivery systems for active ingredients. Therelease profiles show that they were systems comparable to beads formed by other biopolymers and thereforecapable of adequately releasing active ingredients.
Effect of prechlorination prior to activated carbon adsorption on trihalomethanes formation during final disinfection
(Elsevier, 2025-12-17) Gibert Agulló, Oriol; Beltrán Abadia, José Luis; Pablo, Joan de
Granular Activated Carbon (GAC) is commonly used in water treatment for the removal of Dis-solved Organic Matter (DOM) and diminution of the formation of Disinfection By-Products (DBP)during final disinfection. The aim of the present study was to evaluate whether prechlorinationprior to GAC affected the character of DOM and could result in a decrease of trihalomethanes(THM) levels in finished water when postchlorination was applied. DOM character was analysedby fluorescence Excitation-Emission Matrices coupled to Parallel Factor Analysis (EEM + PAR-AFAC). Four different waters (three synthetic solutions containing structurally diverse model andidentifiable fluorescent DOM -tyrosine, tryptophan, and humic substances- and real groundwater)were treated and compared. The solutions were sequentially subjected to prechlorination (atthree different NaClO doses: 0, 4, and 8 mg/L), GAC adsorption, and posthclorination. The resultsshowed that applying prechlorination prior to GAC adsorption resulted in lower concentrations ofTHM in postchlorinated water in comparison to the traditional practice of applying chlorinationonly after the GAC stage. The dose of 4 mg/L NaClO minimised the levels of THM in the finishedwater. The results also revealed that the fulvic-like EEM + PARAFAC component C1G (with λexc= 240 and 325 nm, and λem = 405 nm) showed a high correlation with THM levels and thereforeappeared to be a very good predictor for THM formation. While promising with groundwater, thisnew approach to control THM in chlorinated finished water should be tested with water sourcescontaining DOM with different properties before raising the technology readiness levels to pilotand real full-scale treatment trains.

Examinar

Enviaments recents