Artículos (Química Analítica)

URI permanente para esta colecciónhttps://hdl.handle.net/11441/10909

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Impact of Frozen Storage on Sensory, Physicochemical, and Volatile Compounds Parameters of Different Extra Virgin Olive Oils
(Multidisciplinary Digital Publishing Institute (MDPI), 2024-11-24) Díaz Montaña, Enrique Jacobo; Barbero López, María; Aparicio Ruiz, Ramón; García González, Diego Luis; Morales Millán, María Teresa; Universidad de Sevilla. Departamento de Química Física; Universidad de Sevilla. Departamento de Química Analítica; Ministerio de Ciencia, Innovación y Universidades (MICIU). España
Storage is important for virgin olive oil, a product obtained only during the harvest period, which requires a year-round storage until its best-before date. Low temperatures slow undesirable reactions, though this method is not widely applied. The objective of this paper is to assess the impact of frozen storage on the volatile composition and sensory properties of virgin olive oils. The quality parameters, volatile composition, and sensory profiles were analyzed for samples stored under different conditions (time 0, sixth month supermarket and frozen storage, and long-term-frozen). The physicochemical parameters of the samples stored under supermarket conditions showed significant differences (p < 0.05), with the frozen-storage sample after three months of storage. Additionally, the samples stored under supermarket conditions showed higher volatile concentrations than frozen ones, with increased concentrations of aldehydes and acids producing sensory defects. Thirty-two samples, considered as the long-term-frozen, were divided into three groups depending on the frozen-storage time (1, 6 or 10 years). These long-term-frozen storage samples confirmed the suitability of the proposed oxidation markers (pentanal, hexanal, heptanal, nonanal, acetic, propanoic, butanoic, and hexanoic acids) for differentiating storage conditions and times. This work highlights the oxidation process under different storage conditions and suggests oxidation markers.
Variability of Faecal Microbiota and Antibiotic Resistance Genes in Flocks of Migratory Gulls and Comparison with the Surrounding Environment
(Elsevier, 2024) Jarma, D.; Sacristán Soriano, O.; Borrego, C. M.; Hortas, F.; Peralta Sánchez, Juan Manuel; Balcázar, J. L.; Green, A. J.; Alonso Álvarez, Esteban; Sánchez Melsió, A.; Sánchez Ordóñez, Marta Isabel; Universidad de Sevilla. Departamento de Química Analítica; Universidad de Sevilla. Departamento de Zoología; Gobierno de España; Ministerio de Ciencia, Innovación y Universidades (MICIU). España; Generalitat de Catalunya
Gulls commonly rely on human-generated waste as their primary food source, contributing to the spread of antibiotic-resistant bacteria and their resistance genes, both locally and globally. Our understanding of this process remains incomplete, particularly in relation to its potential interaction with surrounding soil and water. We studied the lesser black-backed gull, Larus fuscus, as a model to examine the spatial variation of faecal bacterial communities, antibiotic resistance genes (ARGs), and mobile genetic elements (MGEs) and its relationship with the surrounding water and soil. We conducted sampling campaigns within a connectivity network of different flocks of gulls moving across functional units (FUs), each of which represents a module of highly interconnected patches of habitats used for roosting and feeding. The FUs vary in habitat use, with some gulls using more polluted sites (notably landfills), while others prefer more natural environments (e.g., wetlands or beaches). Faecal bacterial communities in gulls from flocks that visit and spend more time in landfills exhibited higher richness and diversity. The faecal microbiota showed a high compositional overlap with bacterial communities in soil. The overlap was greater when compared to landfill (11%) than to wetland soils (6%), and much lower when compared to bacterial communities in surrounding water (2% and 1% for landfill and wetland water, respectively). The relative abundance of ARGs and MGEs were similar between FUs, with variations observed only for specific families of ARGs and MGEs. When exploring the faecal carriage of ARGs and MGEs in bird faeces relative to soil and water compartments, gull faeces were enriched in ARGs classified as High-Risk. Our results shed light on the complex dynamics of antibiotic resistance spread in wild bird populations, providing insights into the interactions among gull movement and feeding behavior, habitat characteristics, and the dissemination of antibiotic resistance determinants across environmental reservoirs.
Quantification of Linear Alkylbenzene Sulphonates in Complex Sludge Samples: Influence of Matrix Effects in Calibration Methods
(Elsevier, 2024) Martín Bueno, Julia; Mejías Padilla, Carmen; Santos Morcillo, Juan Luis; Aparicio Gómez, Irene; Alonso Álvarez, Esteban; Heinze, John; Universidad de Sevilla. Departamento de Química Analítica; Universidad de Sevilla
Linear Alkylbenzene Sulfonates (LAS) are among the priority organic pollutants in sludge owing to their high concentrations, due to its use as a major cleaning agent (surfactant) in laundry detergents and household cleaning products, and to the concentration limits of 2,600 mg/kg outlined in the EU directive draft for land application of sludge. In this work, a method has been optimized and validated for the accurate quantification of LAS homologues C10-C13 in different types of samples in the sludge treatment and disposal process including primary, secondary, and digested sludge, compost, and soil. The type of matrix had a significant impact on the method's validation process, resulting in the need of the use of distinct dilution factors for each matrix. Overall, the procedure propose involves a cost-effective and user-friendly technique that combines both extraction and clean-up in a single step (ultrasound-assisted extraction and dispersive solid phase extraction). Analytical determination is conducted using liquid chromatography-tandem mass spectrometry. The method demonstrated excellent accuracy (relative recoveries exceeding 84.5 % across all types of sludge samples) and the limit of quantification enables the measurement of LAS concentrations up to 1000 times lower than the concentration limits stipulated in the EU directive draft. For an accurate quantification, three calibration approaches were tested (external calibration, standard addition, and matrix-matched calibration). Standard addition was the preferred method for quantitative analysis. It helps mitigate matrix effects that could otherwise distort the accuracy of analyte measurements, making it crucial for quality control, especially in monitoring applications where matrix effects may introduce bias into concentration calculations.
Occurrence, Dissipation Kinetics and Environmental Risk Assessment of Antibiotics and their Metabolites in Agricultural Soils
(Elsevier, 2024) Mejías Padilla, Carmen; Martín-Pozo, Laura; Santos Morcillo, Juan Luis; Martín Bueno, Julia; Aparicio Gómez, Irene; Alonso Álvarez, Esteban; Universidad de Sevilla. Departamento de Química Analítica; Ministerio de Ciencia e Innovación (MICIN). España; Universidad de Sevilla; European Union (UE)
Antibiotics are among the emerging contaminants of greatest concern to the scientific community. However, the occurrence and behaviour of their metabolites in soils have been scarcely studied. To address this research gap, this study investigates the occurrence, sorption, dissipation kinetics, and environmental risk of highly important antibiotics (sulfamethazine, sulfadiazine, sulfamethoxazole, trimethoprim) and their main metabolites in Mediterranean agricultural soils. Batch experiments were conducted under natural conditions for 120 days. Five different dissipation kinetics models were applied to elucidate antibiotics degradation. The sorption isotherms were evaluated by three different models. Most of the antibiotics and metabolites tested showed a good fit with the Linear Isotherm model (R2 >0.96) and biphasic dissipation kinetic models (R2 >0.90). The dissipation and the endpoints values (DT50 and DT90) depended on the soil type properties. A Lixisol soil demonstrated reduced degradation of the investigated compounds. Trimethoprim showed the highest persistence, followed by sulfamethazine, sulfamethoxazole, and sulfadiazine. Parent compounds exhibited lower degradation rates than their metabolites. Remaining antibiotic concentrations were found to be below the predicted no-effect concentration in soil, suggesting that they may not pose a risk to terrestrial biota. This study provides valuable insights into the behaviour of these antibiotics and their metabolites in soil.
Determination of Pesticide Residues in Five Different Corn-based Products Using a Single and Simple Solid–liquid Extraction without Clean-up Steps Followed by Comprehensive Two-dimensional Liquid Chromatography Coupled to Tandem Mass Spectrometry
(Elsevier, 2024) Arena, Katia; Martín-Pozo, Laura; Laganà Vinci, Roberto; Cacciola, Francesco; Dugo, Paola; Mondello, Luigi; Universidad de Sevilla. Departamento de Química Analítica; Ministerio de Ciencia, Innovación y Universidades (MICIU). España; Ministerio de Ciencia e Innovación (MICIN). España
Pesticide residues in food products are a critical issue concerning food safety. Recent studies have increasingly focused on developing selective, rapid, innovative, and environmentally friendly analytical methods for detecting pesticides in foodstuffs. This study presents a novel analytical method utilizing comprehensive two-dimensional liquid chromatography-tandem mass spectrometry for the simultaneous determination of one hundred and thirteen multiclass pesticides in corn products. The method simplifies the process with a single-step solid–liquid extraction and benefits from two-dimensional separation to enhance resolution and minimize matrix effects. The methodology was validated according to European Commission DG-SANTE (SANTE/11312/2021) and European Committee for Standardization (EN 15662, 2018) guidelines, obtaining acceptable analytical parameters. Limits of detection ranged from 0.2 µg/L to 30.2 µg/L and limits of quantification from 0.3 to 91.6 μg/L, all bellow regulatory limits. Accuracy, ranged from 60 to 120 % and precision, estimated by relative standard deviation, was consistently below 15.1 % in all cases. The applicability of the method was demonstrated by analyzing pesticides in five representative corn products (tortilla, corn flakes, corn cake, starch, and polenta). Sixteen pesticides were detected, all within the regulatory residue limits. Three metric tools were applied to assess the analytical process. Environmental sustainability was evaluated using the AGREE metric, while analytical performance and method applicability were assessed with the Red-Green-Blue and Blue Applicability Grade Index models, respectively, yielding promising scores (0.5, ≥ 0.55, and 0.65). These findings and the comparison to previous methods indicated that this approach represents a promising, alternative and user-friendly strategy for pesticide determination, offering effective productivity and reliable analytical performance.
Clays-based Geopolymers: a Sustainable Application as Adsorbent of Cytostatic Drugs for Water Purification
(Springer Science and Business Media Deutschland GmbH, 2024) Ben Amor, Assia; Arenas Molina, Marina; Martín Bueno, Julia; Ouakouak, Abdelkader; Santos Morcillo, Juan Luis; Aparicio Gómez, Irene; Alonso Álvarez, Esteban; Hamdi, Noureddine; Universidad de Sevilla. Departamento de Química Analítica; Ministerio de Ciencia e Innovación (MICIN). España
The administration of cytostatic drugs in chemotherapy is steadily increasing, triggering thus a risk to the environment. Identifying powerful ways to effectively remove these hazardous pollutants from hospital and effluent wastewater before they discharge into the aquatic environment remains a critical and challenging task. Adsorption is among the most effective ways to treat contaminated water due to the wide availability and selectivity of the adsorbents besides the simplicity and the low start-up costs of the technique. In this work, a geopolymer, elaborated from an illito-kaolinitic clay (Douiret region of Tunisia) and industrial waste (silica fume and phosphogypsum), has been tested as promising decontamination of the cytostatic drugs paclitaxel (PCX) and irinotecan (IRI) from water samples. The foamed geopolymer was characterized using X-ray diffraction, Fourier transform infrared, scanning electron microscopy and thermogravimetric analysis before and after adsorption. Adsorption batch assays were performed using different concentrations of PCX and IRI, contact times and environmental conditions. The geopolymer had an excellent removal efficiency (almost 100% for PCX and 89% for IRI) using 20 mg of adsorbent and 2.5 mg/L of each drug concentration. The characterization results showed that cytostatic drugs were adsorbed to the geopolymer through physical interactions, pore filling, electrostatic attraction and hydrogen bonding. The specific surface area and pore volume of the geopolymer were 82.23 m2/g and 0.19 cm3/g, respectively. In addition to its cost-effective properties, the geopolymer demonstrated excellent efficiency in contaminated natural samples (including influent, effluent wastewater and surface water) denoting a great application for water purification.
Analytical Quality by Design in the Development of a Solvent-modified Micellar Electrokinetic Chromatography Method for the Determination of Sitagliptin and its Related Compounds
(Elsevier, 2021) Pasquini, Benedetta; Gotti, Roberto; Villar Navarro, Mercedes; Douša, Michal; Renai, Lapo; Del Bubba, Massimo; Orlandini, Serena; Furlanetto, Sandra; Universidad de Sevilla. Departamento de Química Analítica; Ministerio de Educación, Cultura y Deporte (MECD). España
A solvent-modified micellar electrokinetic chromatography method was developed following the Quality by Design approach for the simultaneous determination of sitagliptin (SIT), an oral antihyperglycemic drug, and its main impurities derived from the synthesis process. The separation system was identified in the scouting phase and was made by sodium dodecyl sulphate (SDS) micelles with the addition of n-butanol and methanol. The knowledge space was investigated through an asymmetric screening matrix, taking into consideration eight critical method parameters (CMPs) involving the composition of the background electrolyte in terms of buffer concentration and pH, the concentration of surfactants and organic modifiers, and voltage. The critical method attributes (CMAs) were identified as analysis time and the distance between the tail of the electroosmotic flow system peak and the front edge of impurity I1 (sitagliptin triazole hydrochloride). A Box-Behnken Design was used in response surface methodology for calculating the quadratic models relating the CMPs to the CMAs. From the models it was possible to compute the method operable design region (MODR) through Monte-Carlo simulations. The MODR was identified in the probability maps as the multidimensional zone where the risk of failure to achieve the desired values for the CMAs was lower than 10 %. The experimental conditions corresponding to the working point, with the MODR interval, were the following: background electrolyte, 14 (10−18) mM borate buffer pH 9.20, 100 mM SDS, 13.6 (11.1–16.0) %v/v n-butanol, 6.7 (4.5–8.8) %v/v methanol; voltage and temperature were set to 28 kV and 22 °C, respectively. The developed CE method was validated in accordance with International Council for Harmonisation guidelines and was applied to the analysis of SIT tablets. The routine analysis for the quality control of the pharmaceutical product could be conducted in about 11 min.
Easy, Fast and Environmental Friendly Method for the Simultaneous Extraction of the 16 EPA PAHs using Magnetic Molecular Imprinted Polymers (mag-MIPs)
(Elsevier, 2017) Villar Navarro, Mercedes; Martín Valero, María Jesús; Fernández Torres, Rut; Callejón Mochón, Manuel; Bello López, Miguel Ángel; Universidad de Sevilla. Departamento de Química Analítica
An easy and environmental friendly method, based on the use of magnetic molecular imprinted polymers (mag-MIPs) is proposed for the simultaneous extraction of the 16 U.S. EPA polycyclic aromatic hydrocarbons (PAHs) priority pollutants. The mag-MIPs based extraction protocol is simple, more sensitive and low organic solvent consuming compared to official methods and also adequate for those PAHs more retained in the particulate matter. The new proposed extraction method followed by HPLC determination has been validated and applied to different types of water samples: tap water, river water, lake water and mineral water.
The Smartphone as an Economical and Reliable Tool for Monitoring the Browning Process in Sparkling Wine
(Elsevier, 2017) Pérez Bernal, Juan Luis; Villar Navarro, Mercedes; Morales Gómez, María Lourdes; Úbeda Aguilera, Cristina; Callejón Fernández, Raquel María; Universidad de Sevilla. Departamento de Química Analítica; Universidad de Sevilla. Departamento de Nutrición y Bromatología, Toxicología y Medicina Legal; Comisión Nacional de Investigación Científica y Tecnológica (CONICYT). Chile; Junta de Andalucía
A fast, reliable colorimetric method based on colour measurements obtained from digital images of sparkling wine to study wine browning is proposed. Digital images were obtained, using a smartphone camera and a diffuse light source as the measurement device and, in order to isolate external influences, a suitable blackbox. Images in Red Green and Blue (RGB) colour space were splitted into the three basic channels (R, G, and B) and their values were used to monitor the browning process. Four sparkling Cava wines were monitored during an accelerated browning process. Results showed that while the Red and Green channels remained almost constant, the browning process affected primarily the Blue channel, decay being time-dependent. The Blue channel decay (%Bt) percentage over time is proposed as a new quality marker. This value had a high correlation with absorbance at 420 nm and 5-hydroxymethyl-2-furfural contents. These latter are the most usual markers of wine browning and the results obtained show that %Bt is a good browning descriptor. The advantages of the proposed methodology are single-step multiple samples analysis, affordable instrumentation and the fact that sample preparation is not required.
Comparison of Three Electromembrane-based Extraction Systems for NSAIDs Analysis in Human Urine Samples
(Springer Science and Business Media Deutschland GmbH, 2020) Aranda Merino, Noemí; Ramos Payán, María Dolores; Callejón Mochón, Manuel; Villar Navarro, Mercedes; Fernández Torres, Rut; Universidad de Sevilla. Departamento de Química Analítica; Ministerio de Educación y Ciencia (MEC). España; Ministerio de Ciencia e Innovación (MICIN). España
A comparative study on the extraction efficiency of five non-steroidal anti-inflammatories was carried out using three different electromembrane extraction (EME) devices with different geometries. The employed setups were (a) a hollow fiber configuration (HF-EME), (b) a microfluidic device that allows working in semi-dynamic mode (μF-EME), and (c) a static miniaturized flat membrane device (FM-EME). Each system was applied to the extraction of salicylic acid (SAC), ketoprofen (KTP), naproxen (NAX), diclofenac (DIC), and ibuprofen (IBU) and subsequent determination by high-performance liquid chromatography with UV and fluorescence detection (HPLC/UV-DAD-FLD). Voltage, pH composition, and extraction time were optimized for all devices. Additionally, volume ratio was investigated for HF-EME and FM-EME and flow rate for the microfluidic device. HF-EME provides the best result in terms of sensitivity with a limit of detection (LOD) between 0.1 and 1.5 ng mL−1 for SAC and KTP, respectively, while LODs for μF-EME were between 100 ng mL−1 and 400 ng mL−1 for SAC and DIC, respectively; however, a lower amount of sample was required. Finally, the obtained results, in terms of enrichment factors and extraction recoveries, were discussed to establish the advantages and disadvantages of each device. The proposed EME methods were successfully applied to the determination of the target analytes in fortified human urine samples.
Selective, Rapid and Simultaneous Determination of Ergosterol and Ergocalciferol in Mushrooms by UPLC-Q-TOF-MS
(Elsevier, 2021) Román Hidalgo, Cristina; Villar Navarro, Mercedes; Falcón García, Gonzalo Enrique; Carbonero Aguilar, M. P.; Bautista Palomas, Juan Dionisio; Bello López, Miguel Ángel; Martín Valero, María Jesús; Fernández Torres, Rut; Universidad de Sevilla. Departamento de Química Analítica; Universidad de Sevilla. Departamento de Bioquímica y Biología Molecular; Ministerio de Economía y Competitividad (MINECO). España; Ministerio de Ciencia e Innovación (MICIN). España; European Commission (EC). Fondo Europeo de Desarrollo Regional (FEDER)
An ultra-performance liquid chromatography coupled to atmospheric pressure chemical ionization-quadrupole time-of-flight mass spectrometry method has been optimized and validated for the determination of ergosterol and ergocalciferol in mushroom samples, using cholecalciferol as surrogate standard. The separation was carried out with a Synergi Hydro-RP column (100 mm x 3.00 mm i.d, 2.5 μm particle size), (Phenomenex, CA, USA) column, thermostated at 35 °C. The mobile phase was 0.1 % formic acid aqueous solution and methanol in gradient elution mode and it was achieved in 5 min approximately. Detection was achieved by atmospheric pressure chemical ionization in positive mode and quadrupole time-of-flight mass spectrometry. Desolvation and interface temperatures were set at 500 °C and 150 °C, respectively. The recoveries obtained were within 92–105 % for ergosterol, 77–81 % for ergocalciferol and 83–87 % for cholecalciferol. Method limits of detection were 0.4 and 0.5 μg g−1 for ergosterol and ergocalciferol, respectively, and method limits of quantitation were 1.2 and 1.3 μg g−1 for ergosterol and ergocalciferol, respectively. A rapid and simple extraction procedure using small amount of sample (100 mg) with hexane was optimized and the method was applied to the determination of ergosterol and ergocalciferol in white button mushrooms (Agaricus bisporus var. bisporus) exposed to UV irradiation. Results were compared to the corresponding non-irradiated mushrooms.
Effect of Doxycycline into Clay Minerals under UV light: An Approach of Antibacterial Activity
(Elsevier, 2025) Cardoso da Rocha, Monsuêto; Trigueiro, Pollyana; de Lima, Idglan S.; Santos Filho, Florisvaldo C.; de Oliveira, Luís H.; Fonseca, Maria Gardennia; Medina Carrasco, Santiago; Viseras Iborra, César; Silva-Filho, Edson C.; Orta Cuevas, María del Mar; Anteveli Osajima, Josy; Universidad de Sevilla. Departamento de Química Analítica
Antibiotics are commonly used to treat bacterial infections. However, when these drugs are exposed to light, they can degrade and decrease their antibacterial activity. Here, a study aimed to produce hybrids with the antibiotic doxycycline (DTC) and clay minerals such as montmorillonite, palygorskite, and sepiolite as a strategy to maintain the drug's antibacterial activity against prolonged exposure to UV light. The materials were analyzed using X-ray diffraction, zeta potential, Fourier transform infrared spectroscopy, transmission electron microscopy, textural analysis by N2 adsorption/desorption, and thermogravimetric analysis. The materials were irradiated under 200 hours using UV light. The antibacterial action of the materials (irradiated and non-irradiated) was evaluated against Staphylococcus aureus and Escherichia coli strains. The antibacterial activity of the irradiated materials was better preserved than drugs without protection, especially against Gram-positive bacteria. Therefore, DTC/clay mineral hybrids can maintain the activity of light-sensitive antibiotics even after prolonged exposure to light, making them a promising option for healthcare applications.
Simultaneous and Individual Adsorption of Ibuprofen Metabolites by a Modified Montmorillonite
(Elsevier, 2020) Malvar Guzmán, José Luis; Martín Bueno, Julia; Orta Cuevas, María del Mar; Medina Carrasco, Santiago; Santos Morcillo, Juan Luis; Aparicio Gómez, Irene; Alonso Álvarez, Esteban; Universidad de Sevilla. Departamento de Química Analítica; Universidad de Sevilla
In this work, the applicability of a modified montmorillonite (C18[sbnd]Mt) to remove ibuprofen (IBU) and its main metabolites, 1-hydroxyibuprofen (1-OH IBU), 2-hydroxyibuprofen (2-OH IBU) and carboxyibuprofen (CBX-IBU), simultaneously or separately, from aqueous samples has been evaluated. First, the material was characterized by X-ray diffraction, Fourier-transform infrared spectroscopy and zeta potential measurements. And then, the effect of the experimental conditions (initial concentration, time, temperature and pH) on the adsorption capacity was assessed. A statistical analysis of the adsorption isotherms reveals that Langmuir was the best model in fitting the experimental adsorption data. Maximum adsorption capacities were estimated to be 64, 20, 63 and 19 mg/g for IBU, 1-OH IBU, 2-OH IBU and CBX-IBU, respectively. These values were significantly lower for the mixture solution due to the competition effect for the active sites. Moreover, it was observed that the removal time is quite fast ranging from 20 to 30 min and the adsorption kinetics was predominantly based on the pseudo-second-order model. Characterization studies showed that the main driving force of adsorption was a combination of electrostatic interaction and partitioning. It was also observed that pH had very important effects on the adsorption. C18[sbnd]Mt had proven to be an excellent adsorbent capable to remove new generation pollutants, even at low adsorbent dose making their application economic.
Enhanced porous titanium biofunctionalization based on novel silver nanoparticles and nanohydroxyapatite chitosan coatings
(Elsevier, 2025-04) Castillejo, Ana; Martínez Muñoz, Guillermo; Delgado-Pujol, Ernesto J.; Villalobo Polo, Eduardo; Carrillo de la Fuente, Francisco; Casado Jurado, David; Pérez Bernal, Juan Luis; Begines Ruiz, Belén; Torres Hernández, Yadir; Alcudia Cruz, Ana; Universidad de Sevilla. Departamento de Química Orgánica y Farmacéutica; Universidad de Sevilla. Departamento de Ingeniería y Ciencia de los Materiales y del Transporte; Universidad de Sevilla. Departamento de Química Analítica; Universidad de Sevilla. Departamento de Ingeniería Química; Universidad de Sevilla. Departamento de Microbiología; Ministerio de Ciencia e Innovación (MICIN). España
Titanium is widely used for implants however it presents limitations such as infection risk, stress shielding phenomenon, and poor osseointegration. To address these issues, a novel approach was proposed that involves fabricating porous titanium substrates, to reduce implant stiffness, minimizing stress shielding and bone resorption, and applying polymeric coatings to improve bioactivity. Composite coating prepared from chitosan, silver nanoparticles, and nanohydroxyapatite was optimized to enhance antibacterial properties and promote osseointegration. Chitosan with 80.5 % of deacetylation degree was used to prepare composites with diverse compositions, including different methodologies of adding silver nanoparticles, with silver concentrations below toxic level. Antibacterial activity was tested with three different strains, including Gram+ and Gram− bacteria, demonstrating excellent inhibition after 21 days. In addition, the induction of hydroxyapatite formation was investigated. Finally, the optimal porous metallic substrate that exhibited a more suitable stiffness (29 GPa) (close to the cortical bone tissue they intend to replace) was chosen to be infiltrated with the selected composites. In summary, this synergistic approach based on the combination of porous titanium substrates with 60 vol% porosity and a 355–500 μm pore size distribution coated with 3%CS-nHA-AgNPs-TPP-AgNPsbath composite provided a potential solution to provide implants with improved biomechanical balance and biofunctionality.
Direct capillary electrophoresis analysis of basic and acidic drugs from microliter volume of human body fluids after liquid-phase microextraction through nano-fibrous membrane
(Springer, 2019-11-19) Román Hidalgo, Cristina; Dvořák, Miloš; Kubáň, Pavel; Martín Valero, María Jesús; Bello López, Miguel Ángel; Universidad de Sevilla. Departamento de Química Analítica; Agencia de Subvenciones de la República Checa; Academia Checa de Ciencias
In the present work, a disposable microextraction device with a polyamide 6 nano-fibrous supported liquid membrane (SLM) is employed for the pretreatment of minute volumes of biological fluids. The device is placed in a sample vial for an at-line coupling to a commercial capillary electrophoresis instrument with UV-Vis detection (CE-UV) and injections are performed fully automatically from the free acceptor solution above the SLM with no contact between the capillary and the membrane. Up to 4-fold enrichment of model basic (nortriptyline, haloperidol, loperamide, and papaverine) and acidic (ibuprofen, naproxen, ketoprofen, and diclofenac) drugs is achieved by optimizing the ratio of the donor to the acceptor solution volumes (16 to 4 μL, respectively). The actual setup enables SLM extractions from less than a drop of sample and is suitable for pretreatment of scarce human body fluids. Two unique methods are reported for efficient clean-up and enrichment of the basic and acidic drugs from capillary blood (formed as dried blood spot), serum, and urine samples, which enable their determination at therapeutic and/or toxic levels. The hyphenation of the SLM extraction with CE-UV analysis provides good repeatability (RSD, 2.4–14.9%), linearity (r2, 0.988–1.000), sensitivity (LOD, 0.017–0.22 mg L−1), and extraction recovery (ER, 20–106%) at short extraction times (10 min) and with minimum consumption of samples and reagents.
Continuous electromembrane extraction coupled with mass spectrometry - Perspectives and challenges
(Elsevier, 2018-01-25) Fuchs, David; Román Hidalgo, Cristina; Ramos Payán, María Dolores; Petersen, Nickolaj Jacob;; Jensen, Henrik; Kutter, Jörg P.; Pedersen Bjergaard, Stig; Universidad de Sevilla. Departamento de Química Analítica
This tutorial discusses continuous electromembrane extraction (c-EME) coupled directly to mass spectrometry (MS), and the applicability of such systems for on-line and real-time monitoring of in-vitro drug metabolism. Parent drug substances and corresponding drug metabolites are extracted from the metabolic reaction mixture, through a supported liquid membrane (SLM), and into an acceptor solution on the other side. Extraction is accomplished using an external electrical field sustained over the SLM. The acceptor solution is continuously pumped into the mass spectrometer, and the decline of parent drug as well as the development of metabolites is followed directly with the mass spectrometer. The purpose of the extraction is to avoid proteins and salts from the reaction mixture from entering the mass spectrometer. This tutorial first discusses the principles and theory of operation. Second, technical development is highlighted with special focus on major challenges associated with c-EME-MS systems. Third, operational parameters and performance are discussed, and finally future perspectives and challenges are considered.
New nanostructured support for carrier-mediated electromembrane extraction of high polar compounds
(Elsevier, 2017-01-01) Román Hidalgo, Cristina; Martín Valero, María Jesús; Fernández Torres, Rut; Callejón Mochón, Manuel; Bello López, Miguel Ángel; Universidad de Sevilla. Departamento de Química Analítica; Ministerio de Educación y Ciencia (MEC). España; Universidad de Sevilla
A new support has been proposed to be used for carrier-mediated electromembrane extraction purposes. The new support (Tiss®-OH) is a 100 µm thickness sheet nanofiber membrane manufactured by electrospinning and composed by acrylic nanofibers. It has been used in an electromembrane extraction (EME) combined with a HPLC procedure using diode array detection. The proposed method has been used for the extraction of four high polarity acidic compounds: nicotinic acid, amoxicillin, hippuric acid and salicylic acid. Analytes were extracted from an aqueous sample solution (pH 4) (donor phase) using a Tiss®-OH sheet that supports a 5% (w/v) Aliquat®336 in 1-octanol liquid membrane. Aqueous solution (pH 6) was used as acceptor phase. The electrical field was generated from a d.c. electrical current of 100 V through two spiral shaped platinum wires placed into donor and acceptor phases. Analytes were extracted in 10 min with recoveries in the 60–85% range. The proposed EME procedure has been successfully applied to the determination of the target analytes in human urine samples.
Agar films containing silver nanoparticles as new supports for electromembrane extraction
(Springer, 2014-12-18) Román Hidalgo, Cristina; Ramos Payán, María Dolores; Ocaña González, Juan Antonio; Martín Valero, María Jesús; Bello López, Miguel Ángel; Universidad de Sevilla. Departamento de Química Analítica; Ministerio de Educación y Ciencia (MEC). España
A new support containing silver nanoparticles to assist electromembrane extraction (EME) procedures is proposed. For the first time, synthesized agar films containing silver nanoparticles (AgNPs) have been used as a support for liquid membranes in EME. Agarose films of 20 μm thickness containing 107.9 mg Ag/g agar were synthesized and characterized by transmission electron microscopy (TEM) and atomic force microscopy (AFM), showing isolated spherical silver nanoparticles of 20–30 nm diameter with homogeneous distribution. Nanometallic films were cut and glued to narrow bore glass tubes and used as supports for a dihexyl ether liquid membrane for use in an EME procedure. EME conditions were optimized and applied to the extraction of selected non-steroidal anti-inflammatory drugs (NSAIDs). The results were compared to those using polypropylene membranes (450 μm and 100 μm thickness), achieving 10- to 70-fold higher extraction efficiency. This article opens a new line of research into electrically assisted microextraction systems by combining other possible kinds of nanometallic films, including different metals, film functionalization through metallic NPs, and the use of low polarity solvents. Also, very low currents are obtained during the extraction process, which lead to high electromigration of the analytes.
A Green and Sensitive Electromembrane Extraction (EME) Method for the Determination of Dialkylphosphates in Maternal Urine and Amniotic Fluid
(Elsevier, 2024) Ávila García, Juan Manuel; Fernández Torres, Rut; Sánchez Ruiz, Rocío; Moreno Navarro, Isabel María; Aranda Merino, Noemí; Ramos Payán, María Dolores; Universidad de Sevilla. Departamento de Nutrición y Bromatología, Toxicología y Medicina Legal; Universidad de Sevilla. Departamento de Química Analítica; Ministerio de Ciencia e Innovación (MICIN). España
Organophosphates compounds are extensively used pesticides, whose metabolites, dialkyl phosphates, are considered as bioindicators of human exposure. Recently, research has indicated that they can affect thyroid endocrine function. Pregnant women are a particularly vulnerable cohort to these effects due to concerns about prenatal exposure to environmental pollutants. For the first time an electromembrane microextraction method is proposed for the simultaneous determination of seven dialkylphosphate metabolites in maternal urine and amniotic fluid, which is compatible with mass spectrometry detection and achieves highly sensitive levels of quantitation. Dialkylphosphates were extracted from a 10 mL donor solution at pH 7 into a 50 µL acceptor solution at pH 12 using 1-octanol as the supported liquid membrane and applying 60 V for 10 min at 600 rpm. The obtained extracts were analysed by ion pair liquid chromatography coupled to a triple quadrupole mass spectrometer, using an Acquity UPLC® BEH C18 column (100 mm × 2.1 mm i.d., 1.7 µm particle size) at 30 °C. Under optimal extraction conditions, the preconcentration factors were achieved were up to 178-fold, allowing for high sensitivity levels, in the order of ng mL−1. The limits of quantitation were within 0.075 ng mL−1 (diethyl thiophosphate) and 1.67 ng mL−1 (dimethyl phosphate) in maternal urine samples and within 0.015 ng mL−1 (diethyl thiophosphate) and 0.5 ng mL−1 (dimethyl dithiophosphate) in amniotic fluid samples. The comparative study revealed a significant improvement in terms of analysis time, sensitivity, greenness, and practicality. Finally, the applicability of the method for the determination of selected dialkylphosphates was demonstrated in paired maternal urine and amniotic fluid samples. These results suggest potential placental transfer to the offspring.
Diclofenac Removal by Alkylammonium Clay Minerals Prepared over Microwave Heating
(American Chemical Society, 2024-11-23) França, Denise B.; Silva, Alice P. N.; Osajima, Josy A.; Silva-Filho, Edson C.; Medina Carrasco, Santiago; Orta Cuevas, María del Mar; Jaber, Maguy; Fonseca, Maria G.; Universidad de Sevilla. Departamento de Química Analítica; Universidad de Sevilla
Diclofenac is an emerging contaminant widely detected in water and has had adverse effects on the biota. In this study, the adsorbents were prepared by reacting tetradecyl-(C14), hexadecyl-(C16), and octadecyltrimethylammonium (C18) bromides with sodium vermiculite (Na-Ver) and used for the removal of the first time for diclofenac sodium from aqueous solution. Synthesis was carried out in a microwave-assisted reactor operating at 50 °C for 5 min, using proportions of organic salts in 100 and 200% of the phyllosilicate cation exchange capacity. The stability of loaded alkylammonium solids was evaluated under drug adsorption conditions. Adsorption was mainly influenced by the amount of surfactant incorporated into the clay mineral according to the thermogravimetric and CHN elemental analysis data. Samples prepared with 200% CEC presented lower stability at pH 6.0 and 8.0. Drug adsorption was more effective for C14-Ver-200%, C16-Ver-200%, and C18-Ver-200% samples, with a maximum retention of 97.8, 110.1, and 108.0 mg g–1, respectively. The adsorptive capacities of C14-Ver-200%, C16-Ver-200%, C18-Ver-200%, C14-Ver-100%, C16-Ver-100%, and C18-Ver-100% were reduced to 29.0, 36.8, 41.0, 61.0, 50.4, and 58.0%, respectively, compared with their initial value after three adsorption cycles. X-ray diffraction (XRD) patterns revealed that diclofenac was adsorbed into the interlayer region of organovermiculites. Fourier transform infrared spectroscopy (FTIR), Zeta potential results, and the pH study of adsorption indicated that van der Waals interactions are dominant in the adsorption mechanism.

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