https://uvadoc.uva.es/handle/10324/1346 Dpto. Química Analítica - Artículos de revista 2026-04-11T15:57:49Z https://uvadoc.uva.es/handle/10324/82405 Interest in seaweed as a sustainable source of protein is growing, and deep eutectic solvents (DESs) are a promising green alternative with proven efficacy in protein extraction. This work studies the selective extraction of protein towards carbohydrates from the brown algae Saccharina latissima using DESs. Eleven DESs based on choline chloride (ChCl) and betaine were tested for freeze-dried biomass. The four DESs with the best performance (ChCl:Oxalic acid, ChCl:2Urea, ChCl:2Levulinic acid and etaine:2Urea:Water) were subsequently used to investigate the effect of temperature (20, 30 and 40 ºC) and the addition of water (0 and 47 %) on the extraction process. Betaine:2Urea:Water at 1 h, 40 ºC, and 47 % added water provided the highest protein recovery yield (10.6 %) while minimizing carbohydrate extraction (1.3 %). These results demonstrated similar protein recovery yields to a benchmark process using bead milling, but with better selectivity. Thus, this work provides a sustainable extraction method for the recovery of proteins from seaweed and open new alternatives combining both approaches. 2024-01-01T00:00:00Z https://uvadoc.uva.es/handle/10324/82404 Photobioreactor-based microalgae cultivation offers an integrated approach for nutrient-rich wastewater treatment while producing valuable biomass. One of the main microalgae components is proteins, making them a biotechnological target. In this work, to develop efficient and greener extraction methodologies, aqueous two-phase systems (ATPSs) based on natural deep eutectic solvents (NADESs) were evaluated for one-step protein extraction from microalgae cultivated in swine wastewater. Six ATPSs combining two NADES—betaine:levulinic acid (Bet:2LA) and choline chloride:urea (ChCl:2Urea)—and their individual components (Bet or ChCl) with phosphate salts were compared. Systems {NADES + K3PO4 + water} were characterized and reported for the first time. Protein recovery yield (PRY) and selectivity (protein-to-carbohydrate mass ratio, R) were assessed for three extraction times and at room temperature. The ATPS {Bet:2LA + K3PO4 + H2O} achieved a PRY of 16.4% and remarkable selectivity after 30 min (R = 2.17 g/g), with proteins concentrated in the NADES-rich phase, and negligible recovery in the salt-rich phase. Although the maximum PRY (18.2% at 120 min) was achieved with the precursor betaine, the ATPS with Bet:2LA at 30 min offered an optimal balance between efficiency and process time. With a water content of up to 50%, these systems underscore the potential of NADES-based ATPSs as sustainable platforms for protein recovery. 2026-01-01T00:00:00Z https://uvadoc.uva.es/handle/10324/76071 : The violet innovation grade index (VIGI) is a pioneering metric designed to evaluate the degree of innovation in analytical methods. This study introduces the VIGI tool (https://bit.ly/VIGItool) and demonstrates its application in assessing the innovative potential of various analytical techniques. VIGI integrates ten distinct criteria-sample preparation and instrumentation, data processing and software, white analytical chemistry and its derivatives, regulatory compliance, materials and reagents, miniaturization, automation, interdisciplinarity, sensitivity, and approach-providing a comprehensive evaluation that complements existing green, blue, and red metrics. Each method is assessed using a survey-based approach, resulting in a starshaped decagon pictogram that visually represents its innovation score. The VIGI metric was successfully applied to five case studies, revealing insights into the strengths and weaknesses of each method in terms of innovation. Methods incorporating advanced materials, miniaturized devices, and automation scored highly, reflecting their cutting-edge contributions to analytical chemistry. Conversely, methods lacking advanced data processing or interdisciplinary applications scored lower, highlighting areas for potential improvement. This work underscores the importance of prioritizing innovative metrics like VIGI in the development and evaluation of analytical methods to ensure that analytical chemistry remains at the forefront of scientific advancement through more effective and sustainable practices. 2025-01-01T00:00:00Z https://uvadoc.uva.es/handle/10324/75614 The growing global challenges of wastewater treatment, resource recovery, and environmental pollution are critical in addressing the sustainability of both urban and agricultural systems. Conventional treatment methods often fail to remove pharmaceutical pollutants effectively, which can lead to serious environmental and health concerns. As an alternative, microalgae-based systems have shown potential for addressing wastewater treatment while recovering valuable nutrients. Thus, the present study aims to investigate (i) the removal of pharmaceuticals in microalgae-related wastewater treatment systems, (ii) the variation of biomass productivity and nutrient recovery as a function of the presence of these compounds, and (iii) the feasibility of using the produced biomass in agriculture as a biostimulant. Experiments were performed in pilot-scale thin-layer reactors fed in continuous mode by spiking the inlet wastewater with up to six pharmaceuticals (sulfamethoxazole, trimethoprim, metronidazole, ofloxacin, ciprofloxacin, and diclofenac), selected by its relevance. Results demonstrated that the presence of these compounds does not influence biomass productivity or the fluorescence of chlorophylls as an indicator of the status of the cells. Either, the presence of pharmaceuticals does not reduce the recovery of nutrients, with both biomass productivity and nutrient recovery being linearly related. On average, the removal of CECs was higher in summer (90 %) than in winter (74 %), with variations depending on the pharmaceutical tested. Sulfamethoxazole was the most effectively removed (>91 %), while trimethoprim had the lowest removal rate (>44 %). Most importantly, on average less than 3 % of the pharmaceuticals remain in the biomass, trimethoprim being the contaminant most retained in the biomass (up to 6 %), thus confirming that they are mainly degraded into the mixed liquor. Bioassays performed confirmed the biostimulant capacity of the microalga acting as plant-promoting agents. These results confirm the capacity of microalgae-related wastewater treatment processes to remove pharmaceuticals and to produce safe water and biomass for its final use in agriculture. 2025-01-01T00:00:00Z https://uvadoc.uva.es/handle/10324/75157 In the last decade, the instrumentation improvements in supercritical fluid chromatography (SFC) and the hyphenation to mass spectrometry (MS), have increased the SFC acceptance between scientists, becoming today a valuable tool in analytical chemistry. The unique selectivity, short analysis times, low consumption of organic solvents, and the greener mobile phase, have contributed to expanding its applicability which has led to an increase in the number of publications especially in the bioanalysis area. This work reviews the advantages and main applications of SFC in bioanalysis during the last 5 years. Fundamental aspects concerning mobile phase composition, stationary phase, hyphenation to MS as well as matrix effect have been discussed. Finally, the most relevant applications have been summarized. 2024-01-01T00:00:00Z https://uvadoc.uva.es/handle/10324/74560 In this study, the feasibility of two sample treatments has been evaluated for the determination of seven neonicotinoid insecticides in honey from different botanical origins using ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC–MS/MS). A solid phase extraction with a polymeric sorbent (Strata® X) is proposed for analyzing dark honeys, while a QuEChERS (quick, easy, cheap, effective, rugged and safe) approach is recommended for light honeys. Chromatographic analysis (6 min) was performed on a core-shell column (Kinetex® EVO C18). The proposed methods were fully validated using two different MS/MS systems: quadrupole-time-of-flight and triple quadrupole. The results showed that the best overall analytical performance was achieved using triple quadrupole, mainly due to its better sensitivity and the reduced influence of the matrix onto the analyte signals. The methods developed were applied to the analysis of commercial honey samples from different regions of Spain, as well as from experimental apiaries. 2018-01-01T00:00:00Z https://uvadoc.uva.es/handle/10324/73296 A new analytical method was developed and validated to determine fourteen bisphenols (A, B, C, E, F, M, P, S, Z, AF, AP, BP, FL, PH) in bee pollen using ultra-high-performance liquid chromatography-tandem mass spectrometry. Two different sample treatments were proposed and evaluated: one based on the QuEChERS (quick, easy, cheap, effective, rugged & safe) approach and the other utilizing microextraction with a supramolecular solvent (SUPRAS). In both cases, average analyte recovery ranged between 71 % and 114 %, and the matrix effect was between −45 % and +5 %, although it was not significant when using the QuEChERS-based method (<±20 %). The environmental impact of both sample treatments was assessed using different analytical metrics, with both procedures classified as environmentally friendly, though slightly better results were obtained for SUPRAS. The method was fully validated, showing that the QuEChERS approach had better overall performance, particularly regarding sensitivity and matrix effect. Consequently, the QuEChERS methodology was applied to determine bisphenols in thirty bee pollen samples from different Spanish regions. Residues of three bisphenols (M, P, and S) were detected, although only bisphenol S was quantified in several samples at low concentration levels (<7 μg kg−1), which is below the established specific migration limit (SML; 50 μg kg−1). However, regarding human health, the estimated daily intake, target hazard quotient, and hazard index assessed were higher than acceptable limits, suggesting a potential risk for human consumers. 2024-01-01T00:00:00Z https://uvadoc.uva.es/handle/10324/73286 The determination of plasticizers in bee pollen may be important not only to evaluate the contamination of the hive environment, but also to verify the safety for consumers of this food supplement, since to date it has not been studied. Therefore, a new analytical methodology for the determination of nine plasticizers (phthalate esters: di-(2-ethylhexyl) phthalate, dibutyl phthalate, dimethyl phthalate, diethyl phthalate, benzyl butyl phthalate, and di-n-octyl phthalate; diphenyl ethers: 4-bromodiphenyl ether and 4-chlorodiphenyl ether; adipate: bis(2-ethylhexyl) adipate) in bee pollen using gas chromatography-mass spectrometry was developed. An efficient sample treatment (modified QuEChERS, quick, easy, cheap, effective, rugged & safe) is proposed (with average analyte recoveries between 77 % and 104 %) involving extraction with acetonitrile followed by a dispersive solid phase extraction (enhanced matrix removal lipid sorbent). Chromatographic analysis (<21 min) was performed in an Agilent HP-5MS column under programmed temperature conditions, and analyses were performed in selected ion monitoring mode. The method was validated in terms of selectivity, limits of detection (0.2–17.2 μg kg−1) and quantification (0.5–57.5 μg kg−1), linearity, matrix effect, trueness, and precision (relative standard deviation < 15 %). Finally, an analysis of thirty samples from different sources (commercial or experimental apiaries) revealed the presence of residues of five plasticizers in all samples. Quantification was possible in several cases, with overall concentrations ranging from 0.056 to 3.152 mg kg−1. This study not only reports for the first time the presence of some plasticizers in bee pollen, but also corroborates the usefulness of bee pollen as bioindicator of environmental contamination. 2024-01-01T00:00:00Z https://uvadoc.uva.es/handle/10324/73081 A novel method has been proposed to determine nine plasticizers in honey samples by gas chromatography–mass spectrometry. An efficient sample treatment was proposed (average analyte recoveries between 77% and 118%) involving a double solvent extraction with ethyl acetate, followed by a clean-up step with florisil. Chromatographic analysis (< 21 min) was performed in an Agilent HP-5MS column under programmed temperature conditions. The greenness of the method was assessed with different tools that classified it as environmentally friendly. The method was validated in terms of selectivity, limits of detection (0.1–3.1 μg kg−1) and quantification (0.2–10.3 μg kg−1), linearity, matrix effect, trueness, and precision (relative standard deviation <9%). An analysis of thirty samples from different sources (commercial or experimental apiaries) revealed the presence of residues of five plasticizers in most of the samples. Finally, health risk assessment was evaluated, and the results indicated no associated health risks for consumers. 2024-01-01T00:00:00Z https://uvadoc.uva.es/handle/10324/72958 A new analytical methodology was proposed to determine fourteen bisphenols in honeys from different botanical origins using ultra-high performance liquid chromatography-tandem mass spectrometry. A fast, efficient, environmentally-friendly and simple sample treatment (recoveries between 81% and 116%; matrix effect <20% for all studied compounds except for bisphenol E, F and S) was proposed, which involved a solvent microextraction with acetone and a small volume/amount of 1-hexanol. Chromatographic analysis (< 15 min) was performed in a Kinetex EVO C18 column under gradient elution mode. The method was validated in terms of selectivity, limits of detection (0.2–1.5 μg/kg) and quantification (0.5–4.7 μg/kg), linearity, matrix effect, trueness, and precision (relative standard deviation <17%). Finally, thirty honey samples were analyzed, revealing the presence of residues of nine bisphenols in some of them. However, quantification was possible only in two cases for bisphenol A, with a concentration of approximately 13 μg/kg. 2024-01-01T00:00:00Z https://uvadoc.uva.es/handle/10324/72946 Swine farming produces large quantities of nutrient-rich wastewater, which often contains metals such as Cu and Zn, used as feed additives for pigs. These metals must be removed from the wastewater before discharge but their retention in the biomass can limit its subsequent utilization. Photobioreactors are a very promising alternative for swine wastewater treatment, as the consortium of microalgae and bacteria growing symbiotically in these reactors allows high nutrient and metal removal efficiency at moderate costs. This work studies the mechanisms of removal of Cu(II) and Zn(II) by the two types of microorganisms growing in these photobioreactors. A microalga commonly used in wastewater treatment (Scenedesmus almeriensis) and an activated sludge were kept in contact with synthetic wastewater containing 100 mg/L of Cu and Zn. After 72 h, Scenedesmus almeriensis removed 43% of Cu and 45% of Zn, while activated sludge removed 78% of Cu and 96% of Zn. Single and sequential extractions of the biomasses using different extracting reagents revealed that biosorption on protonable groups is the dominant removal mechanisms. Mild reagents solubilized 69% of Cu and 94% of Zn from the microalgae and 76% of Cu and 93% of Zn from the activated sludge. Low metal concentrations in the oxidizable and residual fractions evidenced minimal bioaccumulation inside the cells. FTIR and ESEM-EDX analysis confirmed biosorption by ion exchange and complexation as the main metal remediation mechanisms. The weak bonds of the biosorbed Cu and Zn ions are beneficial for the valorization of biomass and the obtaining of safe bioproducts. 2024-01-01T00:00:00Z https://uvadoc.uva.es/handle/10324/72860 The presence of microplastics in food poses a significant concern due to its potential impact on human health. Numerous studies have focused on spectroscopic techniques to identify and confirm those contaminants in food, but less attention has been paid to chromatographic techniques. Thus, this article provides a comprehensive review of the recent applications of chromatographic techniques in the analysis of microplastics and related compounds such as bisphenols and phthalate esters in food from 2018 to 2022. The study covers and discusses a range of different chromatographic applications (gas and liquid chromatography). Furthermore, this review also explores different sample treatments employed for extracting these compounds from food matrices, while offering a detailed analysis of their principles, advantages, and disadvantages. This review provides readers with an overview and valuable insights into the analytical performance and potential applications of these chromatographic techniques in the analysis of microplastics and related compounds in food. 2024-01-01T00:00:00Z https://uvadoc.uva.es/handle/10324/69569 Winemaking involves contact at different stages with atmospheric oxygen, the consumption of which determines its final properties. The chemical analysis of red wines subjected to consecutive cycles of air saturation has been extensively researched; however, the capacity to consume different doses of oxygen before bottling is an aspect that has been little studied. In this work, the effect of saturation of different levels of oxygen on the final characteristics of different wines made from Tempranillo and Garnacha grape extracts was studied. For this purpose, the wines were subjected to controlled oxygen saturation levels to simulate their possible oxygenation before bottling. The only difference was the phenolic composition of grape extracts that were reconstituted under the same conditions to avoid the interferences inherent to the fermentation process and the additives added in the winery. The kinetics of oxygen consumption was then evaluated and its effect on the color, antioxidant capacity, and phenols of three different wines was analyzed. This work shows the relationship between the oxidation state of wine and changes in its chemical composition. In addition, it provides insight into the effect of oxygen consumption before bottling on the properties of wines subjected to high and single doses of oxygen. 2023-01-01T00:00:00Z https://uvadoc.uva.es/handle/10324/69388 This work presents the study of the effectiveness of different inert gases applied during racking to prevent oxygen uptake by wine. Inert gases were used for the purging of empty tanks and hoses before the start of each racking, as well as for blanketing in the full racked tank. After analyzing these operations with the different inert gases, the required volumes of each gas were optimized. The CO2:Ar (20:80) mixture proved to be the most effective for the complete purging of the empty tank, while CO2 was the most cost-effective gas. Purging the empty tank with 25% vessel volume gas was sufficient to achieve useful inerting with all the gases studied, as well as to maintain low levels of dissolved oxygen (DO) in the wine filling the tank. Applying 0.5 of vessel volume of Ar, CO2:Ar (20:80), and CO2 gases during blanketing allowed the headspace oxygen (HSO) of the racked tank to be protected throughout. During the racking of a white wine in a commercial winery, Ar showed the highest efficiency, compared to N2, for both the inerting of empty hoses and destination tank and for maintaining low levels of DO and HSO in the tank. 2023-01-01T00:00:00Z https://uvadoc.uva.es/handle/10324/68038 The design, construction and validation of a device for the accurate measurement of the dissolved oxygen content in wine and simultaneously the variation of its spectral fingerprint is presented. The novelty of this system is due to two innovative approaches. First, robustness in measurements is obtained by using cuvettes designed to simultaneously measure the dissolved oxygen and color. Secondly, automatic monitoring is performed to ensure that measurements are always taken at the same cuvette position. The fine-tuning of the device with the study of white and red wines makes it possible, on the one hand, to establish the appropriate measurement conditions and, on the other hand, to determine the amount of oxygen required to cause specific changes in the wine spectrum, information that could not be obtained until now. The preliminary results are very interesting, presenting precise data on the amount of oxygen consumed by the wine and the variations in its visible spectrum, thus reflecting the modification of the responsible phenolic compounds. This information is of great interest, since it helps to optimize the handling of the wine and, if necessary, to moderate the uptake of oxygen in each type of wine to ensure the maintenance of the color during the winemaking and conservation processes of each type of wine. The results of the experiments indicate that this new instrument is feasible and accurate for detecting oxygen changes during wine production. 2023-01-01T00:00:00Z https://uvadoc.uva.es/handle/10324/67982 Sparging is a technique to remove an excess of dissolved oxygen from the wine with inerting gases before bottling to avoid negative consequences for its chemical and sensory properties. However, its effectiveness on these properties has not been studied in depth. This work investigates the effectiveness of different inerting gases (N2, CO2, and argon) in removing dissolved oxygen in different volumes of a model wine. The efficacy of these gases was also studied in white and red wine, as was their effect on the physicochemical characteristics. Sparging with N2 in the model wine gave the best results in terms of cost–benefits, and with CO2 the worst. The scaling in tanks of different sizes allowed us to establish that the N2 expenditure ranged between 0.09 L and 0.23 L of gas per liter of model wine, establishing an index (Lgas/Lwine) that can be very useful for wineries to remove the dissolved oxygen. Sparging treatments in white and red wine showed very similar results to the model wine. The effect on the chemical properties of the wines was, in some cases, different for white and red wine and for each gas used. The incorporation of oxygen and the subsequent sparging produced a significant loss of some volatile compounds of sensory interest and increased the content of others that have a negative sensory effect. In addition, it had a negative effect on the chromatic properties of red wines. 2023-01-01T00:00:00Z