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The Meeting of the Electrochemistry Group of the Spanish Royal Society of Chemistry (RSEQ) is an annual event that has taken place since the late 1970s. The meeting brings together the entire Spanish electrochemistry community at a single event to discuss the latest advances in our field, and normally takes place in different Spanish cities. Over the last decade, mainly due to the deep economic crisis experienced in Spain, the number of electrochemists trained in Spain who have emigrated and today lead important groups in other European countries and in the USA has grown significantly. Thus, the XLI Meeting of the Electrochemistry Group was organized in Paris (France) in 2021, and served to regroup all electrochemists trained in Spain, both emigrants and residents. By holding the meeting outside of Spain, the Electrochemistry Group aimed to internationalize the group's meetings and to strengthen collaborations with the French electrochemistry community. [ABSTRACT FROM AUTHOR]

The degradation of laboratory oil paint film specimens containing indigo and Prussian blue pigments and pictorial samples from the Sant Francesc de Paula painting exhibited in the Tomàs Balvey Arxiu Museum (Cardedeu (Catalonia), Spain) has been studied by voltammetry of immobilized particles. This technique, combined with light microscopy, scanning electron microscopy-energy dispersive X-ray analysis, nanoindentation-atomic force microscopy, attenuated total reflectance-Fourier-transform infrared spectroscopy and gas chromatography–mass spectroscopy techniques permits the proposal of a dual scheme for the degradation of the pigments when naturally aged and submitted to accelerated UVA aging. Under conditions of moderate temperature, humidity and natural illumination, and low gradients of these parameters, Prussian blue acts as a radical scavenger moderating the production of reactive oxygen species produced in the oil binding medium by the action of ultraviolet radiation, resulting in the formation, in the solid state, of the solid-solution, {KFeIII[FeII(CN)6]}x{FeIII[FeIII(CN)6]}1–x, known as Berlin green, which then promotes the formation of indigo adducts with radicals. In several localized areas of the Sant Francesc de Paula paint showing strong degradation, Prussian blue acts as a promoter of the indigo oxidation to isatin, thus resulting in a considerable chromatic shift. [ABSTRACT FROM AUTHOR]

[Display omitted] • Decuprification/desilvering process on gold objects is electrochemically monitored. • Repetitive voltammetry of immobilized particles methodology is used. • Different electrochemical types associated to manufacturing methods are characterized. • Electrochemical dating of archaeological gold artifacts is described. The use of repetitive voltammetry for dating archaeological gold objects is described. The method involves the record of the gold- silver-, and copper-related voltammetric responses obtained for metal nanosamples attached to graphite electrodes immersed into HCl electrolytes. This methodology permits to characterize different electrochemical types representative of different manufacturing techniques. Age estimates are based on the assumption that decuprification/desilvering processes advance with time under reasonably uniform conditions. Age calibration curves covering a range of ca. 2500 years were obtained from a set of archaeological samples from the Mapungubwe Gold Collection at the University of Pretoria Museums, South Africa, the Rijksmuseum of Amsterdam, The Netherlands, the Rheinische Landesmuseum Trier of Mannheim (Germany), the Museu de Belles Arts de Castelló, Spain, the Museu de Segovia, Spain, and the repository of the Servei d'Investigació Arqueològica Municipal de València, Spain. [ABSTRACT FROM AUTHOR]

Caring for a relative with autism spectrum disorder (ASD) entails being under chronic stress that could alter body homeostasis. Electrodermal activity (EDA) is an index of the sympathetic activity of the autonomic nervous system related to emotionality and homeostasis. This study compares EDA in response to acute stress in the laboratory between parents of people with (n = 30) and without (n = 34) ASD (caregivers and non-caregivers, respectively). Caregivers showed lower EDA in response to acute stress than non-caregivers. They also presented higher trait anxiety, anger, depression, and somatic symptoms than non-caregivers. Higher EDA was related to a worse mood and more severe somatic symptoms only in caregivers. These results could reflect an adaptive habituation to stress and establish that high EDA in response to acute stress depends on caregivers' health. [ABSTRACT FROM AUTHOR]

An essentially non-invasive electrochemical methodology addressed to the authentication of archaeological lead is described. The method is based on the record of the voltammetric response of nanosamples from the archaeological artefact mechanically transferred to a graphite 'pencil' electrode in contact with aqueous buffers. Three diagnostic criteria for authentication are described based on the appearance of: (i) oxidative dissolution signals for trace metals like copper, arsenic, antimony and, often, tin and silver accompanying stripping peaks for lead, (ii) peak potential shifts for reduction peaks for patination products, and (iii) the presence of reduction peaks for PbO2. The method is applied to the authentication of an Iberian lead plate from the Tossal de Sant Miquel (Llíria, Spain) site using a series of genuine and false pieces from different provenances in the Valencian region (Spain). [ABSTRACT FROM AUTHOR]

Abstract: Electrochemistry allows for rapid identification of multiple metals and other chemical complexes common in acid rock drainage (ARD) systems. Voltammetric scans using a single gold microelectrode of water samples from geochemically distinct areas of the Río Tinto (RT) in southwestern Spain were clearly recognizable in the field and in samples stored at room temperature for over 6months. Major voltammetric peaks of iron(III) and copper(II) were identified on a single constantly renewable gold microelectrode. Confirmation of these peaks was performed by spiking with standard metal solutions in the laboratory. This voltammetric technique is a rapid, direct and inexpensive in situ method for identification of water sources and their chemical characteristics, as well as an economical way to monitor environmental changes and remediation efforts. [Copyright &y& Elsevier]

This paper describes the application of sliced inverse regression to model the electrochemical process of aluminum smelter plants. Real data measurements obtained during several years in a Spanish industrial environment are used to illustrate the main dependencies between parameters. Nonlinear relations between the output variables and relevant linear combinations of input variables are deduced. An exploratory statistical analysis is also presented, checking for correlations and possible linear dependencies. [ABSTRACT FROM AUTHOR]

Abstract: The main obstacles of most renewable energies are their variability and availability; thus, we propose the ‘hydrogen option’ as a means of energy management, and we study its feasibility in a specific wind farm. The installation will be capable to store electrochemically the surplus energy and return the electricity to the grid during the peak hours. The solution was to connect the system, so that we store the energy as hydrogen when the wind generation exceeds a threshold; this is done by an electrolyzer set, with the appropriate nominal power, where, besides the electrical conversion devices, we have designed a control programme for tuning the voltage and current densities to the optimal operation of the cells. To utilize the hydrogen downstream the storage subsystem, we have selected a fuel-cell and the output is finally converted to the grid requirements. The nominal power of the wind farm studied is 48.8 MW, and it generates 18.4% of surplus electricity which cannot be evacuated through the node during the off-peak hours; this is converted into nearly 13 GWh of hydrogen per year, which can be used to produce peak electricity (raising the power of the hybrid system to 12.3%). Thus, it presents many advantages, which could facilitate the penetration of the wind resource, leading to a cleaner energy production and moving one step forward to the ‘hydrogen economy’. [Copyright &y& Elsevier]

The article discusses the use of an electro-chemical activation system for disinfecting Legionella pneumophila in hospital water storage facilities. A study was made on such a system in a Spanish hospital, testing it before and after installation. This was in response to a finding that the outbreak of Legionella can often be traced to hospital potable water sources. The effect of Legionella on patients is discussed, as well as the rates of electro-chemical treatment of the water storage facilities found to be infected.

This report proposes a refined method to date archaeological gold samples based on the Tafel analysis of the ascending part of voltammetric curves corresponding to the oxidation of surface flakes of gold in contact with hydrochloric acid aqueous electrolyte. This allows estimating the equilibrium potential of gold oxidation correcting for irreversibility effects. This equilibrium potential can be correlated with the coverage of adsorbed oxygen species and hence the estimated age of the gold samples. A satisfactory potential/time calibration graph was constructed from a set of archaeological samples including two sets of samples from the Mapungubwe Gold Collection, South Africa (1200–1290 CE) and Santa Llúcia, Alcalà de Xivert in Spain (dated back 600-550 BCE) sites. The dated samples come not only from different continents, but their ages also cover more than 3000 years. Image 1 • Electrochemical dating of archaeological gold samples is based on the voltammetry of immobilized particles. • Samples from the Mapungubwe Gold Collection (1200–1290 CE) and Santa Llúcia archaeological site (600-550 BCE) were studied. • Peak potentials and peak currents for gold oxidation in 0.10 M HCl are used. [ABSTRACT FROM AUTHOR]

US-based FuelCell Energy has announced a partnership with Spanish utility company Abengoa to develop localized stationary fuel cell power plants for markets in Europe and Latin America. The partners will also install a 300 kW pilot project at the Abengoa headquarters in Seville. [ABSTRACT FROM AUTHOR]

This work presents an integrated electrodisinfection/electrocoagulation (ED-EC) process for urban wastewater reuse that employs iron bipolar electrodes. Boron doped diamond (BDD) was used as the anode and stainless steel (SS) as the cathode. A perforated iron plate was introduced between the anode and cathode to function as a bipolar electrode. This ED-EC combined cell makes it possible to conduct the simultaneous removal of microbiological content and elimination of turbidity from urban wastewater. The results show that current densities greater than or equal to 6.70 A m(-2) enable complete disinfection of the effluent and the removal of more than 90% of its initial turbidity. Hypochlorite and chloramines formed during the ED-EC process were found to be the main compounds responsible for the disinfection process. Furthermore, a cell configuration of cathode (inlet)-anode (outlet) improves the process performance by enhancing turbidity removal. Finally, the influence of the bipolar electrode material (iron or aluminium) was assessed. The results indicate that the efficiency of the electrodisinfection process depends mainly on the anodic material and is not influenced by the material of the bipolar electrode. In contrast, the removal of turbidity is more efficient when using iron as a bipolar electrode, especially at low current densities, due to the formation of a passive layer on the aluminium that hinders the dissolution of the bipolar electrode., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

A useful tool based on a single-step extraction and clean-up procedure for the determination of 15 organohalogenated pollutants (including brominated flame retardants) in aquaculture samples, using aluminium oxide basic and acidic silica gel in the supercritical extraction cell followed by gas chromatography with electron capture detection or mass spectrometry has been developed. This effective clean-up step ensures a minimum of chromatographic difficulties related to complex matrix components such as aquaculture feed. The extraction procedure has been screened by a fractional factorial design for the preliminary statistically significant parameters. The factors selected were extraction temperature, pressure, static extraction time, dynamic extraction time and carbon dioxide flow rate. The Doehlert design, followed by a multicriteria decision-making strategy, was then performed in order to determine the optimum conditions for the two most significant factors: pressure (165 bar) and dynamic extraction time (27 min). Under optimal conditions, the procedure developed with GC-MS/MS provides an excellent linearity, detection (0.01-0.2 ng g(-1)) and quantification limits (0.05-0.8 ng g(-1)) for most of the analytes investigated. The feasibility of the proposed supercritical fluid extraction method was validated by analysing two reference materials and fish feed and shellfish samples with satisfactory results.

In this study nine organochlorine pesticide residues (alpha-, beta-, and gamma-hexachlorocyclohexane (HCH), hexachlorobenzene (HCB), aldrin, p,p'-DDE, p,p'-DDD, o,p'-DDT, and p,p'-DDT) in forty nine samples of honey collected from markets of Portugal and Spain during 2001 and 2002, respectively, were evaluated. For this evaluation, three analytical procedures were studied. The analytical procedure, based on LLE extraction with ethyl acetate followed by gas chromatography-electron-capture detection (GC-ECD) for quantification, and mass spectrometry (GC-MS) for confirmation, has been selected. Recoveries of spiked samples ranged from 68%, for beta-HCH, and 126% for p,p'-DDT, for fortification levels between 10 and 100 microg/kg, and 64%, for alpha-HCH, and 143% for gamma-HCH for fortification levels between 20 and 200 microg/kg. Limits of quantification, using GC-ECD, were from 0.01 and 0.10mg/kg, and limits of detection between 0.001 and 0.02 mg/kg. Fourteen Valencian samples were contaminated, containing residues of HCB or/and HCH isomers. The frequency of detection was 56% for Spanish samples. In Portugal, 23 samples were contaminated, what means 95.8%. In Spanish samples, concentrations range from nd to 0.03 mg/kg for HCB, and nd to 2.24 mg/kg for HCH-total. The mean concentration and standard deviation were 0.017+/-0.011 mg/kg for HCB, and 0.579+/-0.747 mg/kg for HCH-total, contributing the gamma isomer with the highest values. The samples from Portugal showed higher levels. Levels of HCB ranged from nd to 0.39 mg/kg. HCH-total ranged from nd to 4.86 mg/kg, and DDT-total from nd to 0.658 mg/kg. Mean concentration and standard deviation were 0.09+/-0.116 mg/kg for HCB, 1.357+/-1.30 mg/kg for HCH-total, and 0.143+/-0.193 mg/kg for DDT-total.

Water salinity represents an environmental stress for many species. Amphibians are particularly sensitive because they are generally poor osmoregulators, and most species are completely absent from brackish and saline environments. We experimentally examined the effect of different salinity levels on larvae of the toad Bufo calamita L., a species that occupies freshwater ponds but can also breed in brackish ponds. Two independent experiments are reported here. In both experiments, tadpoles under saline conditions (ranging between 85 and 200 mOsm) showed a slower developmental rate, metamorphosing between 4 and 9 d later than the controls. Bufo calamita tadpoles reared in brackish water increased their osmolality and solute concentration (mainly sodium and chloride), decreased their levels of glucose, and decreased the total protein content, all measured from whole-animal extracts. Although most larval anurans are strictly ammoniotelic until the completion of metamorphosis, a few species exposed to dehydrating environments have evolved the ability to use urea as an osmolyte during the larval phase. The data presented here reveal that although B. calamita seems to be yet another exception to the rule of larval strict ammoniotelism, the tadpoles are not able to use urea as an osmolyte and rely on sodium-chloride balance instead. Preliminary immunoassays of thyroid hormone content suggest a possible decrease in hormone levels induced in water salinity conditions that correlate with a decreased developmental rate.

An efficient method for the determination of nanogram levels of zinc in waters (potable, irrigation, waste and sea waters) is described. Acidified water samples were analyzed by an accurately optimized time/temperature program for electrothermal atomic absorption spectrometry. The samples were previously treated with a matrix modifier consisting of 0.1% Mg(NO3)2 in 0.5 M HNO3 and injected through a graphite tube with L'Vov platform. Sample recoveries, repeteability, and analyses of NIST reference material demonstrated the reliability and accuracy of this technique. Zinc concentrations ranged from 2.0 to 73.0 microg l(-1). No significant differences among the mean zinc levels determined in the four types of water considered from southeastern Spain were found. Zinc concentrations in waters from the zone were not affected by human and industrial activity.

The immediate effects of intense aerobic exercise on the composition and oxidizability of low- (LDL) and high-density lipoproteins (HDL) were studied in 11 male athletes. Plasma parameters known to affect lipoprotein oxidizability were also evaluated. Lipophilic antioxidants, including alpha-tocopherol and carotenoids, paraoxonase and malondialdehyde (MDA) in plasma remained unchanged after exercise. Increases in the concentration of uric acid, bilirubin and ascorbic acid after the race resulted in a significant increase in total antioxidant serum capacity. LDL, but not HDL, increased its "in vitro"-induced susceptibility to oxidation and the proportion of electronegative LDL (LDL-). The ability of HDL to inhibit the oxidation of LDL remained unchanged after exercise. The enhanced oxidizability of LDL was not explained by increments in its aldehyde content or by decrements in antioxidants. The major compositional change in LDL was an increase in non-esterified fatty acid (NEFA) content (from 4.00+/-1.24 to 19.00+/-14.18 mol NEFA/mol apoB). NEFA also increased in plasma and HDL. "In vitro" experiments showed that incubation of LDL with increasing amounts of NEFA induced a concentration-dependent increase in the proportion of LDL-. Moreover, a slightly increased NEFA content in LDL (15-50 mol NEFA/mol apoB) induced higher susceptibility to oxidation. These "in vitro" results concur with those observed in LDL obtained from athletes after exercise, i.e. a concentration of approximately 20 mol NEFA/mol apoB increased LDL oxidizability and LDL- proportion. We conclude that changes in the qualitative characteristics of LDL after exercise were unrelated to oxidative stress, but were related to the increase in LDL-associated NEFA content.

Five modifiers were tested for the direct determination of cobalt in coal fly ash and slag by ultrasonic slurry-sampling electrothermal atomic absorption spectrometry (USS-ETAAS). The furnace temperature programs and the appropriate amount for each modifier were optimized to get the highest signal and the best separation between the atomic and background signals. Nitric acid (0.5% v/v) was the most adequate chemical modifier for cobalt determination, selecting 1,450 degrees C and 2,100 degrees C as pyrolysis and atomization temperatures, respectively. This modifier also acts as liquid medium for the slurry simplifying the procedure. The remaining modifiers enhanced the background signal, totally overlapped with cobalt peak. The method optimized gave a limit of detection of 0.36 microg g(-1), a characteristic mass of 13 +/- 1 pg and an overall-method precision which is highly satisfactory (<7%, RSD). The method was validated by analyzing two certified coal fly ash materials, and satisfactory recoveries were obtained (83-90%) and no statistical differences were observed between the experimental and the certified cobalt concentrations. Additionally, certified sediment, soil and urban particulate matter were assayed; again good results were obtained. The developed methodology was used to determine cobalt in several coal combustion residues from five Spanish power plants.

A method using differential pulse anodic stripping voltammetry after microwave oven digestion was developed for the simultaneous determination of Cd(II) and Pb(II) in the deciduous teeth of children. Each tooth was weighed; deposited in a 120 mL capped Teflon vessel with 5 mL 65% nitric acid, Suprapur analytical grade; and digested in a 2-step microwave oven for 15 min. The detection limits for Cd(II) and Pb(II) in the final solution were 0.078 and 0.323 microg/L, and the quantitation limits 0.394 and 1.613 microg/L, respectively, with a linearity range of 2 microg/L for Cd(II) and 23.3 microg/L for Pb(II). The sensitivity was 2.51 nA/microg-L and 1.37 nA/microg-L, for Cd(II) and Pb(II). The main advantages of this technique are a complete and satisfactory dissolution of the tooth material with the proposed microwave oven digestion procedure, without sample pretreatments, such as drying, ashing, or powdering. The voltammetric procedure proved to be well designed because of significant goodness of fit to a linear model, and the accuracy of the method was established as compared with standard reference material. The methodology has enabled us to study Cd(II) and Pb(II) in 371 deciduous teeth from school children in Cartagena, Spain.

A reliable and rapid method is described for the determination of chromium in alcoholic beverages by electrothermal atomic absorption spectrometry (ETAAS) after optimization of the temperature-time program for the graphite furnace. Chromium in wines was determined directly without sample pretreatment. Other samples were first mineralized with HNO3 and V2O5. The method was validated, and its analytical characteristics were checked. The detection limit was 1 pg (for a sample volume of 10 microL). Accuracy was 99.20 +/- 3.80% for wines and 98.90 +/- 2.00% for other beverages. Precision ranged from 3.50 to 4.50%. The proposed method was applied to 124 samples of alcoholic beverages frequently consumed in Spain. Mean values obtained (microgram/L) were 20.28 for wines, 8.75 for beer, 7.85 for cider, 14.60 for brandy, 7.50 for rum, 10.25 for whisky, 8.80 for gin, 9.25 for vodka, 24.45 for anisette, and 10.08 for liquors. The advantages of the proposed method (rapidity, sensitivity) and versatility) make it useful for routine analyses and for estimations of dietary intake of chromium.

The differential pulse anodic stripping voltammetry (DPASV) method described is based on the one reported by Hasse et al., but adapted to normal laboratory conditions. The values obtained in the estimation of the analytical parameters (linearity, detection and quantification limits, precision and accuracy) show that in the conditions described the method is sensitive enough, reliable and useful for determining these elements in infant formulas. A comparison between DPASV and atomic absorption spectroscopy (AAS) methods in the conditions described here shows that the former is less sensitive but that they are similar in precision. The cadmium, copper, lead and zinc contents of different types of infant formulas marketed in Spain are reported.