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Phenylboronic acids (BAs) are important synthetic receptors that bind reversibly to cis-diols enabling their use in molecular sensing. When conjugated to magnetic iron oxide nanoparticles, BAs have potential for application in separations and enrichment. Realizing this will require a new understanding of their inherent binding modes and measurement of their binding capacity and their stability in/extractability from complex environments. In this work, 3-aminophenylboronic acid was functionalized to superparamagnetic iron oxide nanoparticles (MNPs, core diameter 8.9 nm) to provide stable aqueous suspensions of functionalized particles (BA-MNPs). The progress of sugar binding and its impact on BA-MNP colloidal stability were monitored through the pH-dependence of hydrodynamic size and zeta potential during incubation with a range of saccharides. This provided the first direct observation of boronate ionization pKa in grafted BA, which in the absence of sugar shifted to a slightly more basic pH than free BA. On exposure to sugar solutions under MNP-limiting conditions, pKa moved progressively to lower pH as maximum capacity was gradually attained. The pKa shift is shown to be greater for sugars with greater BA binding affinity, and on-particle sugar exchange effects were inferred. Colloidal dispersion of BA-MNPs after binding was shown for all sugars at all pHs studied, which enabled facile magnetic extraction of glucose from agarose and cultured extracellular matrix expanded in serum-free media. Bound glucose, quantified following magnetophoretic capture, was found to be proportional to the solution glucose content under glucose-limiting conditions expected for the application. The implications for the development of MNP-immobilized ligands for selective magnetic biomarker capture and quantitation from the extracellular environment are discussed. The authors would like to acknowledge the financial support from Science Foundation Ireland under Grant Agreements 13/CDA/2155 and 16/IA/4584, the work was also co-funded under the European Regional Development Fund (13/RC/2073_2). P.B.P. acknowledges the Government of Spain - Ministry of Education, Culture and Sports for the FPU grant (FPU14/04589).

In this work, the determination of different metals (i.e., Al, Cr, Cu, Mn, Ni and V) in engine lubricating oils by microwave plasma atomic emission spectrometry (MP AES) has been revisited. For this purpose, a new multinebulizer in combination with the standard dilution analysis (SDA) calibration methodology has been used. The microwave plasma is very unstable and may even extinguish when organic solvents are directly introduced. This problem can be avoided by the synergetic combination of the SDA calibration and the new multinebulizer since it allows the determination of analytes in complex matrices due to the simultaneous introduction of organic and aqueous solutions, favoring the plasma stabilization. Furthermore, the SDA calibration also corrects the matrix effects associated with complex matrices. For the purpose of comparison, the same study has been performed using conventional calibration methodologies (i.e., external calibration (EC), internal standard calibration (IS) and standard addition calibration (SA)). To compare the analytical performances, the analytical figures of merit (i.e., limit of detection and limit of quantification) and the accuracy (i.e., trueness and precision) of the results have been evaluated. The results obtained show very similar values for the SDA calibration compared to the other calibrations with a much lower consumption of reagents, resources and with a higher easiness of operation. In addition, the total analysis time has also been evaluated, which has emphasized the great advantage of the synergetic association of SDA calibration with the multinebulizer in chemical analysis. The authors would like to thank the Spanish Ministry of Science and Innovation (PID2021-126155OB-I00) and the Regional Government of Valencia (Spain) (CIPROM/2021/062, INVEST/2022/70) for the financial support.

The university stage is a good time to promote healthy eating strategies. The sociological and cultural changes experienced by students lead them to skip meals, increase their intake of fast food and energy-dense foods, decreasing adherence to the Mediterranean diet (MD). Professionals related to food such as nutritionists and dietitians are also considered a population at risk of developing eating disorders due to the extensive knowledge they possess, which can be used for both good and bad practice. The objective was to analyze the impact of a 4-month educational program promoting the Mediterranean diet on risky eating behaviors, adherence to the Mediterranean diet, and body composition in nutrition and dietetics students, studying the differences according to the group investigated (control group and educated group). The context of the research was 196 students (49 males and 147 females) from two consecutive years. The control group did not receive any type of intervention, while with the control group (educated) an educational program was carried out. Results showed that women with greater control over energy intake, carbohydrates, and sugar had a lower percentage of fat mass, while in men, the relationship was established with weight. Regarding adherence to the Mediterranean diet, at post, it is adequate in both men (8.25 ± 2.87) and women (7.90 ± 2.89), with no significant differences between the intervention groups. This work was supported by a grant from the University Teaching Research Networks Program of the Institute of Education Sciences of the University of Alicante (2021-22). Ref: 5628.

A new natural deep eutectic solvent (NADES)-based analytical method for mercury speciation in water samples is presented. A NADES (i.e., decanoic acid:DL-menthol in a molar ratio of 1:2) is used as an environmentally friendly extractant for separation and preconcentration using dispersive liquid–liquid microextraction before LC-UV–Vis. Under optimal extraction conditions (i.e., NADES volume, 50 µL; sample pH, 12; volume of the complexing agent, 100 µL; extraction time, 3 min; centrifugation speed, 3000 rpm; and centrifugation time, 3 min), the limit of detection values were 0.9 µg L−1 for the organomercurial species and 3 µg L−1 for Hg2+, which had a slightly higher value. The relative standard deviation (RSD, n = 6) has been evaluated at two concentration levels (25 and 50 µg L−1) obtaining values for all the mercury complexes within the range of 6–12% and 8–12%, respectively. The trueness of the methodology has been evaluated using five real water samples from four different sources (i.e., tap, river, lake, and wastewater). The recovery tests have been performed in triplicate obtaining relative recoveries between 75 and 118%, with RSD (n = 3) between 1 and 19%, for all the mercury complexes in surface water samples. However, wastewater sample showed a significant matrix effect (recoveries ranged between 45 and 110%), probably due to the high amount of organic matter. Finally, the greenness of the method has also been evaluated by the analytical greenness metric for sample preparation (i.e., AGREEprep). Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. The Spanish Ministry of Science and Innovation (PID2021-126155OB-I00) and the Regional Government of Valencia (Spain) (CIPROM/2021/062) provided financial support for this study.

An on-line synthesis of CDots is proposed for the first time, using the flow injection analysis (FIA) technique, which was coupled, in a single system, to the analytical determination of aluminium in water samples. The nanoparticles were obtained from the carbonization of glucose and iron(III) in an acidic medium, and their photoluminescence increased in the presence of aluminium ions. Under optimal experimental conditions, the proposed method has shown an acceptable linearity range –between 0.04 and 3.0 mg L−1 (R2 = 0.9999) – and a detection limit of 0.007 mg L−1. The analysis of drinking water and groundwater samples showed good accuracy (recoveries ranged between 91 – 113%) and RSD% < 13. The on-line system exhibited a high sample throughput (36 h−1), since no incubation time was required. Financial support from Universidad Nacional del Sur (PGI 24/Q099 and 24/Q123, CONICET 11220200102603CO, CONICET 11220200103198CO and the ANPCyT PICT-2019-04458 (2021-2023) is gratefully acknowledged. This research was part of the Ph.D. thesis of Damian Uriarte, which was supported by a doctoral grant funded by Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET). M. Garrido and C.E. Domini wish to thank CONICET.

A simple, sensitive and matrix-effect free analytical method for simultaneous determination of Cd, Hg and Pb in drug samples (i.e., commercial dosage tablets) by inductively coupled plasma optical emission spectrometry (ICP OES) has been developed. According to the United States Pharmacopeia (USP) Chapter 232, those metals are considered elemental impurities from class 1 and they must be assessed in pharmaceutical production as well as in quality control evaluation. In order to increase the sensitivity of the analysis, dispersive liquid–liquid microextraction (DLLME) was performed and seven factors affecting analyte extraction were optimized by multivariate analysis. A microvolume of analyte enriched phase was directly introduced into the plasma using a multi-nebulizer, providing a high enrichment factor. When compared to conventional ICP OES analysis, DLLME improves the limit of quantitation (LOQ) values on average 40-fold for all analytes. Consequently, LOQ values were significantly lower than their permissible daily exposure limits for oral drugs. Accuracy was evaluated by addition and recovery experiments following USP recommendations in eight commercial drug samples. Recovery and RSD values were within the range of 90–108% and 1–9%, respectively. The authors are grateful to the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq, process no. 141634/2017-0, 202722/2019-8, 305201/2018-2 and 428558/2018-6), the Regional Government of Valencia (Spain) (PROMETEO/2018/087) for the financial support, Agilent Technologies Inc. for the loan of the ICP OES spectrometer, and Ingeniatrics for the MultiNeb® provided. This study was financed in part by the Coordenaçao de Aperfeiçoamento de Pessoal de Nível Superior – Brasil (CAPES) – Finance Code 001. The authors extend their appreciation to Ministry of Science, Innovation and Universities for granting the Spanish Network of Excellence in Sample Preparation (RED2018-102522-T). This article is based upon work from the Sample Preparation Study Group and Network, supported by the Division of Analytical Chemistry of the European Chemical Society.

In this work a green and fast sample preparation method based on reversed-phase dispersive liquid–liquid microextraction (RP-DLLME) was developed for the separation and preconcentration of several elements (i.e., Ag, As, Ba, Cd, Cr, Cu, Hg, Mn, Mo, Ni, Pb, S, Se, Sn and V) in gasoline samples before determination by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). The extraction procedure was carried out in a reverse mode, since a small volume of the aqueous phase (i.e., 8 M HCl) is used to extract a relatively high volume of the organic phase (i.e., gasoline sample). Unlike conventional DLLME, in RP-DLLME the analytes were extracted from the organic phase into the aqueous phase. The experimental conditions for the microextraction procedure were: 5 g of sample, 8 M HCl as the extractant phase, mechanical agitation by vortex as the dispersion system, 115 μL of extractant volume, and 2 min extraction and 5 min centrifugation time. Under optimized extraction conditions the enrichment factor ranged between 3 and 53, and the limits of detection ranged between 0.02 and 50 μg kg−1. The proposed analytical method was validated and successfully used to analyze three gasoline samples. All gasoline samples were spiked at 100 μg kg−1 for all analytes, except sulfur (in this case at 1000 μg kg−1), obtaining recovery and RSD values within the range of 88–109% and 2–9%, respectively. The authors would like to thank the Regional Government of Valencia (Spain) (PROMETEO/2018/087) for the financial support, Agilent Technologies Inc. for the loan of the ICP-OES spectrometer, and Ingeniatrics for the OneNeb® provided. Financial support from Universidad Nacional del Sur is gratefully acknowledged. A. S. Lorenzetti, E. Vidal and C. E. Domini wish to thank Consejo Nacional de Investigaciones Científicas y Técnicas for the financial support received. The authors extend their appreciation to the Ministry of Science, Innovation and Universities for granting the Spanish Network of Excellence in Sample Preparation (RED2018-102522-T). This article is based upon work from the Sample Preparation Study Group and Network, supported by the Division of Analytical Chemistry of the European Chemical Society.

Introduction: Population-based fecal tests for colorectal cancer (CRC) screening have shown to reduce mortality thanks to the early detection of the disease. However, currently available fecal tests are limited in their sensitivity and specificity. Our aim is to look for volatile organic compounds in fecal samples as biomarkers for CRC detection. Material and Methods: Eighty participants were included; 24 had adenocarcinoma, 24 had adenomatous polyps and 32 presented no neoplasms. Fecal samples were collected 48 h preceding the colonoscopy from all participants, except CRC patient samples that were collected after 3–4 weeks from the colonoscopy. Magnetic headspace adsorptive extraction (Mag-HSAE) followed by thermal desorption-gas chromatography-mass spectrometry (TD-GC–MS) was performed on stool samples to identify volatile organic compounds as biomarkers. Results: p-Cresol was significantly more abundant in the cancer samples (P < 0.001) with an area under the curve (AUC) of 0.85 (CI 95%; 0.737–0.953), having a sensitivity and specificity of 83% and 82%, respectively. In addition, 3(4H)-dibenzofuranone,4a,9b-dihydro-8,9b-dimethyl- (3(4H)-DBZ) was also more abundant in the cancer samples (P < 0.001) with an AUC of 0.77 (CI 95%; 0.635–0.905), sensitivity of 78% and specificity of 75%. When combined (p-cresol and 3(4H)-DBZ), the AUC was 0.86, sensitivity 87% and specificity 79%. p-Cresol also appeared to be promising as a biomarker for pre-malignant lesions with an AUC of 0.69 (CI 95%; 0.534–0.862), sensitivity 83% and specificity 63%, P = 0.045. Conclusions: Volatile organic compounds emitted from feces and determined by a sensitive analytical methodology (Mag-HSAE-TD-GC–MS), employing a magnetic graphene oxide as extractant phase, could be used as a potential screening technology for CRC and pre-malignant lesions. Miren Alustiza would like to thank ISABIAL for her pre-doctoral grant (UGP-16-138/2016/45). This work was supported by the Instituto de Salud Carlos III (PI17/01756, PI20/01527); by Vicerrectorado de Investigación y de Transferencia de Conocimiento (UAUSTI18-04, UAUSTI19-05, UAUSTI20-04), and Conselleria d’Innovació, Universitats, Ciència i Societat Digital (Generalitat Valenciana) (PROMETEO/2018/087; CIPROM/2021/062). The authors extend their appreciation to the Ministry of Science, Innovation and Universities for granting the Spanish Network of Excellence in Sample Preparation (RED2018-102522-T).

A novel simple, environmentally friendly and portable method to determine vitamin E in edible oils based on reversed-phase dispersive liquid-liquid microextraction combined with electrochemical detection using screen-printed carbon electrodes (SPCEs) has been developed. Vitamin E was extracted from oil samples into a 4 M HCl aqueous solution and determined by differential pulse voltammetry using SPCEs. The extraction conditions optimized by experimental design (i.e., Plackett-Burman and central composite designs) were: aqueous 4 M HCl extractant volume, 43 µL; extraction time, 2 min; centrifugation time, 10 min; and centrifugation speed, 3000 rpm. The proposed method requires a standard addition calibration approach, and the working range showed good linearity from 0 to 20 mg L−1, with a correlation coefficient ranging from 0.990 to 0.995 (N=5). The methodological limit of detection was between 1 and 3 mg L−1. The repeatability of the proposed method was evaluated at 15 mg L−1, and the relative standard deviation ranged between 10 and 15% (n=5). For the quantification of vitamin E in ten commercial samples of olive, sesame, soybean, sunflower and a mixture of sunflower and corn oils, the volume of the extractant phase (i.e., 4 M HCl aqueous solution) was increased up to 100 µL and satisfactory recoveries were obtained in the range of 85-115%, confirming the applicability of the method. The authors would like to thank the Ministry of Science and Innovation of Spain (project no. CTQ2016-79991-R) and Generalitat Valenciana (Spain) (project nos. GVA/2014/096 and PROMETEO/2018/087) for the financial support. A.D. gratefully acknowledges the University of Alicante and the research group “Atomic-mass spectroscopy and analytical chemistry under extreme conditions” for giving the opportunity for implementation of the research project and the Scientific Grant Agency of the Ministry of Education of the Slovak Republic (VEGA 1/0010/15) for financial support. E.F. also wishes to thank the Spanish Ministry of Education for her FPU grant (FPU13/03125). The authors extend their appreciation to Ministry of Science, Innovation and Universities for granting the Spanish Network of Excellence in Sample Preparation (RED2018-102522-T). This article is based upon work from the Sample Preparation Study Group and Network, supported by the Division of Analytical Chemistry of the European Chemical Society.

La etapa universitaria es un buen momento para promover estrategias de alimentación saludable. Los cambios sociológicos y culturales que sufren los estudiantes los llevan a saltarse comidas, ingesta de comida rápida, alimentos hipercalóricos, siendo la adherencia a la Dieta Mediterránea baja. Los profesionales relacionados con la alimentación, como los nutricionistas y dietistas, además, son considerados población de riesgo en desarrollar trastornos alimentarios, debido al amplio conocimiento que poseen, pudiendo utilizarlo tanto para buena como para mala praxis. El contexto de la investigación fue el alumnado de primer curso del Grado en Nutrición Humana y Dietética. El objetivo de la investigación fue analizar el efecto de factores de adherencia a la dieta mediterránea, de composición corporal y trastornos del comportamiento alimentario en estudiantes del grado de nutrición humana y dietética, comparar los resultados en función del porcentaje de masa grasa y establecer correlaciones entre variables. Los resultados muestran que las mujeres que mayor autocontrol y restricción dietética presentan son las que menor porcentaje de masa grasa tienen. La prevalencia de estudiantes con bajo peso es de 8,49% mientras que de sobrepeso y/o obesidad es de 10,38%. De forma general la adherencia a la dieta mediterránea es adecuada en hombres y debe mejorar ligeramente en las mujeres.

Several strategies have been effectively tested in the past to improve the Laser Induced Breakdown Spectroscopy (LIBS) signal for the analysis of liquid samples, involving peculiar experimental configurations, such as Double Pulse LIBS (DP-LIBS). Recently, sample treatment has proven to be a viable and simple way to enhance the performances of LIBS towards the analysis of solutions. Among the various strategies, the most promising and versatile appears to be Thin Film Microextraction (TFME) using carbon-based adsorbents. Another sample pre-treatment procedure, Nanoparticle-Enhanced LIBS (NELIBS), has gained significant interest due to its relative simplicity and effectiveness. This methodology uses a deposition of silver nanoparticles (AgNPs) on the sample to greatly increase the emission of the LIBS plasma. In this work, we investigate for the first time the possibility of combining TFME and NELIBS. We developed TFME supports by depositing an aqueous graphene nano-sheets (aq-GRA) prepared by Pulsed Laser Ablation in Liquid (PLAL) on a glass substrate. The preparation of the supports was optimized with regards to the substrate nature, deposition method, sorbent volume and drying method. Then, the TFME supports were tested for the extraction of Chromium from aqueous solution at different extraction times and analyte concentration. Subsequently, the TFME supports were treated with a deposition of silver nanoparticles (AgNP) to test the feasibility of the NELIBS approach. We observed an enhancement in the emission lines of Cr when the AgNPs were applied, as well as a lower estimated LOD value when compared to plain graphene TFME supports. M. Hidalgo is grateful to Ministerio de Economía, Industria y Competitividad [CTQ2016-79991-R] and Conselleria de Educación, Investigación, Cultura y Deporte (Regional Government of Valencia, Spain) [PROMETEO/2018/087] for the financial support.

This case study investigates the exposure of 119 Spanish women of reproductive age to 5 essential (Co, Cu, Mn, V, Zn) and 10 toxic (Ba, Be, Cs, Ni, Pb, Pt, Sb, Th, Al, U) elements and assesses their risk. The essential elements (Co, Cu, Mn, V, and Zn) showed average concentrations (GM: geometric mean) of 0.8, 35, 0.5, 0.2, and 347 μg/L, respectively. Five of the toxic elements (Ba, Cs, Ni, Al, U) exhibited detection frequencies of 100%. The GM concentrations of the novel toxic elements were 12 μg/L (Al), 0.01 μg/L (Pt), 0.02 μg/L (U), 0.12 μg/L (Th), 0.009 μg/L (Be) and 4 μg/L (Cs). The urine analysis was combined with a survey to assess any variations between subgroups and potential predictors of exposure to elements in the female population. Significant differences were obtained between the rural and urban areas studied for the toxic element Cs, with higher levels found in mothers living in urban areas. In relation to diet, statistically significantly higher levels of essential (Cu) and toxic (Ba) elements were detected in women with a high consumption of fish, while mothers who consumed a large quantity of legumes presented higher levels of the toxic element Ni (p = 0.0134). In a risk-assessment context, hazard quotients (HQs) greater than 1 were only observed for the essential elements Zn and Cu in P95. No deficiency was found regarding the only essential element for which a biomonitoring equivalent for nutritional deficit is available (Zn). For the less-studied toxic elements (Al, Pt, U, Th, Be, and Cs), HQs were lower than 1, and thus, the health risk due to exposure to these elements is expected to be low for the female population under study.

Magnetic deep eutectic solvents (MDESs) have recently produced a torrent of pioneering applications in endless areas of sample preparation. By including a magnetic nanomaterial (e.g., magnetic nanoparticles) or a paramagnetic anion (e.g., [FeCl4]-) in their structure, MDESs exhibit a strong response under the application of an external magnetic field. Furthermore, the use of MDESs, as a sorbent or solvent in extraction techniques, have been scarcely employed to develop green analytical methods, characterized by the avoid of time-consuming steps and the use of toxic organic solvents, as well as the application of small amounts of MDESs, for the determination of organic and inorganic contaminants, drugs, proteins, among others in environmental, food and biological matrices. This review highlights the application of MDESs in sample preparation in analytical chemistry. Challenges and future outlooks of new MDESs are also presented. The authors would like to thank the Regional Government of Valencia (PROMETEO/2018/087) for the financial support. The authors extend their appreciation to Ministry of Science, Innovation and Universities for granting the Spanish Network of Excellence in Sample Preparation (RED2018-102522-T). This article is based upon work from the Sample Preparation Study Group and Network, supported by the Division of Analytical Chemistry of the European Chemical Society.

Two analytical methods based on miniaturized electrochemical sensors, voltammetric and amperometric sensors, have been developed for the determination of 6-methyl-2-thiouracil (MTU) in meat consumption samples (beef liver and foie). A multivariate approach has been considered to optimize the experimental procedure including extraction and electrochemical detection. Under optimal conditions and at a typical working potential of 1.55 V (vs Ag pseudo-reference electrode), response is linear in the range 0 to 20 µg L−1 MTU concentration range. The empirical limit of detection is 0.13 µg L−1, lower than the maximum concentration established by legislation. The electrochemical methods have been used to analyze MTU-spiked meat samples, and recovery values varying between 85 and 95% with coefficients of variation

In this work, a solid phase microextraction procedure, denoted as Thin Film Microextraction (TFME), was combined with Laser-induced Breakdown Spectroscopy for the detection of several analytes in aqueous solutions (Cu, Cr, Ni and Pb). The adsorbent films, consisting of a thin layer of graphene oxide deposited on glass substrates, were generated by using the electrospray deposition technique (ESD). Several parameters affecting the quality and shape of the films resulting from the ESD process were studied, and the morphology and adsorption capacity of the films were evaluated. The generated films were used for extraction of the target analytes from aqueous solutions and, after extraction, the analytes-enriched adsorbents were analysed by LIBS without the need of any desorption or elution step. In order to assess the analytical capability of the TFME-LIBS procedure, different analytical figures of merit of the proposed TFME-LIBS methodology were evaluated. The obtained limits of detection were 14 μg kg−1 for Pb and 15 μg kg−1 for the rest of the tested analytes. Measurement repeatability was better than 4% RSD at low concentration level (20 μg kg−1) but deteriorated by increasing the concentration level at 100 μg kg−1, with %RSD ranging from 3.6% (Cr) to 24% (Pb). Method trueness, evaluated from the analysis of a real sample of bottled water, led to recovery values in the range 85%–106%. This work was supported by the Spanish Ministry of Economy and Competitiveness [CTQ2016-79991-R], the Regional Government of Valencia (Spain) [PROMETEO/2013/038 and PROMETEO/2018/087]; and the University of Alicante [UAUSTI17-04 and UAUSTI18-04]. L. Ripoll is grateful to the Ministry of Economy and Competitiveness for her PhD fellowship (FPI-MICINN (BES-2012-058759)).

A novel approach is presented to determine four bisphenols in water and urine samples, employing magnetic dispersive solid‐phase extraction combined with liquid chromatography and diode array detection. A modified zeolite‐based magnetic composite was used as an efficient sorbent, combining the advantages of magnetic materials with the remarkable properties of zeolites. A multivariate optimization design was employed to optimize some experimental factors affecting magnetic dispersive solid‐phase extraction. The method was evaluated under optimized conditions (i.e., amount of sorbent, 50 mg; sample pH, unadjusted; NaCl concentration, 1.25%; extraction and elution time, 2 min; eluent solvent, ethanol; eluent solvent volume, 400 µL), obtaining good linearity with correlation coefficients ranging between 0.995 and 0.999 (N = 5) (from 2 to 250 µg/L for bisphenol A, bisphenol AP, and bisphenol P and from 5 to 250 µg/L for bisphenol AF). Method repeatability was assessed obtaining coefficients of variation between 3 and 11% (n = 6). Finally, the method was applied to spiked real samples, obtaining for water samples relative recoveries between 83 and 105%, and for urine samples between 81 and 108% for bisphenol A, bisphenol AP, and bisphenol AF, and between 47 and 59% for bisphenol P. The authors would like to thank the Spanish Ministry of Economy and Competitiveness and European Union (FEDER funds) (project no. CTQ2016-79991-R) and Generalitat Valenciana (Spain) (project no. PROMETEO/2018/087) for the financial support. P. Baile also thanks Ministry of Education, Culture and Sports for her FPU grant (FPU14/04589).

A new concept of a nebulizer (i.e., multinebulizer) has been employed for trace element (e.g., Cd, Cu, Hg, Ni, Pb, and Zn) determination in marine biota samples (e.g., fish sample). To this end, an analytical methodology based on the combination of a multinebulizer with an isotope dilution (ID) calibration strategy and inductively coupled plasma mass spectrometry (ICP-MS) has been proposed. In this way, the on-line isotope dilution (OID) is accomplished by the simultaneous introduction of the liquid samples/standard and the isotopic reference solution (i.e., spike) into the plasma with an efficient mixing between them, which takes place at the inner cavity of the multinebulizer tip. The proposed OID-ICP-MS analytical methodology allows the fast determination of Cd, Cu, Hg, Ni, Pb and Zn in a biota sample certified reference material (CRM) (e.g., IAEA-476) with limits of detection of 0.006, 0.4, 0.09, 30, 0.2 and 4 ng g−1, respectively, and recovery values ranging from 97 to 103%. The primary advantage offered by the proposed analytical methodology is that the time-consuming spiking step in the conventional ID analysis is avoided. This yields savings in both the total time and cost of the analysis per sample. Hence, it has been proved that OID-ICP-MS using a multinebulizer is a promising solution for the trace element analysis of samples with a high matrix content, which simplifies operation and significantly increases sample throughput and productivity. The authors would like to thank the Ministry of Economy and Competitiveness of Spain (Project no. CTQ2016-79991-R, AEI/FEDER,UE) for the financial support, the Vice-Rectorate for Research and Knowledge Transfer of the University of Alicante for the funds to cover the expenses of the use of Research Technical Services (UAUST119-05), and Ingeniatrics for the MultiNeb® provided. The IAEA is grateful for the support provided to its Environment Laboratories by the Government of the Principality of Monaco.

This study is the first to use a new ZSM-5 zeolite-based composite decorated with iron oxide magnetic nanoparticles and modified with hexadecyltrimethylammonium bromide surfactant (i.e., HDTMA-ZSM-5/Fe2O3) as an efficient sorbent for magnetic dispersive solid-phase extraction (MDSPE) of nonsteroidal anti-inflammatory drugs in water and urine samples with subsequent measurement by liquid chromatography diode array detection. Experimental factors affecting MDSPE were optimized using a multivariate optimization strategy. The optimum experimental conditions were: amount of sorbent, 40 mg; sample pH, 2.2; NaCl concentration, 2.5%; extraction time, 2 min; eluent solvent, methanol; eluent solvent volume, 424 μL; and elution time, 2 min. The linearity of the method was studied from 3.3 to 400 μg L−1 (N = 8) for ketoprofen, from 1.7 to 400 μg L−1 (N = 8) for felbinac, from 6.6 to 400 μg L−1 (N = 7) for diclofenac and from 9.9 to 400 μg L−1 (N = 6) for ibuprofen. Method repeatability was evaluated at 10 and 200 μg L−1 spiking levels, obtaining coefficients of variation between 2 and 5% (n = 6). Limits of detection, determined empirically, were 1.0 μg L−1 , 0.5 μg L−1, 2.0 μg L−1 and 3.0 μg L−1 for ketoprofen, felbinac, diclofenac and ibuprofen, respectively. Tap water, reservoir water, wastewater and five urine samples were selected to assess method applicability. Recovery values ranged between 86–107% and 80–112% for water and urine samples, respectively, showing negligible matrix effects. Finally, this method was employed to monitor ibuprofen excretion in real urine samples. The authors would like to thank the Spanish Ministry of Economy and Competitiveness and European Union (FEDER funds) (project n. CTQ2016-79991-R) for the financial support. P. Baile also thanks Ministry of Education, Culture and Sports for her FPU grant (FPU14/04589).

A new portable and simple 3D printed device was designed for free chlorine determination in water samples. The analytical method was based on the quenching caused by free chlorine on the fluorescence emission of the carbon dots (CD) synthesized from citric acid and urea. The fluorescence was captured through the camera of a smartphone, which was coupled to the 3D printed device, and the images were processed using the RGB system by the ImageJ 1.51q software. The proposed method was selective and precise (RSD% 4.6, for n = 6), and the trueness of the results was evaluated by comparing the results obtained with those recovered by the spectrophotometric method 4500-Cl G (standard method), with good agreement between them. Moreover, the remarkable correlation between the CD signal and the free chlorine concentration resulted in a determination with low detection limits (limit of detection of 6 μg L−1 and limit of quantification of 20 μg L−1). Therefore, the new method and the related portable device could be considered a fast, economical and reliable alternative for the on-site determination of free chlorine in water samples. The authors wish to thank the financial support received from Universidad Nacional del Sur (PGI 24/Q099 and 24/Q086) and the ANPCyT (PICT-201-0659). The authors also thank Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) particularly for the doctoral grant of D. Uriarte.

The advantages of the microwave plasma atomic emission spectrometry (MP-AES) for hydride generation (HG) by means of modified Multi Mode Sample Introduction System (MSIS®) have been revealed for analysis of As and Sb in complex real samples. Two main outcomes have been achieved: (i) reliable analysis and higher tolerability to less diluted matrices and (ii) a multifold reduction in the methodological limits of detection (MLOD). For the first time in real samples analysis the HG is assisted by silica-coated magnetic nanoparticles (MNPs) (∼2 mg mL−1 MnFe2O4@SiO2) added to the hydrogenation reagent stream (1.5% NaBH4). This innovative approach provides smooth hydrides generation from problematic matrices, better gas–liquid separation and steady gas transport from the MSIS chamber. The effect is due to the elimination of NaBH4 delivery interruptions, the foam suppression in the reactor and levelling the carbon amount carried to the MP. The used inert MNPs could be collected from the drain with a permanent magnet and appear to be recyclable and reusable without memory effect or efficiency loss. The achieved benefits are demonstrated in the determination of As and Sb in three types of complex matrices: industrial electrolyte with high dissolved solids content, human urine prone to intensive foam creation, and sparkling mineral water releasing CO2. The work was supported by NSF of Bulgaria, Project DN19/9 2017–2021 (INISA).

El presente trabajo desarrollado en la Universidad de Alicante en el Grado de Química analiza, desde el punto de vista tanto del alumnado como del profesorado, los posibles motivos que favorecen, o dificultan, la matriculación de los y las estudiantes en asignaturas impartidas en inglés. Para ello, se ha empleado la metodología de cuestionario lo que ha permitido recolectar de forma fiable, y anónimamente, la opinión de cada uno de los participantes (i.e., alumnado y profesorado). Los cuestionarios se han realizado utilizando un enfoque mixto, es decir, se ha analizado información tanto cuantitativa como cualitativa. La muestra está compuesta por los y las estudiantes del curso académico 2020-2021 y del profesorado que imparte docencia en inglés en asignaturas del Grado en Química de la Universidad de Alicante. El análisis de los resultados revela interesantes resultados en la percepción del alumnado y el profesorado con relación a los factores motivacionales frente a la docencia en inglés. Esta visión dual puede ser de gran utilidad para la Facultad de Ciencias de la Universidad de Alicante tanto para el desarrollo de nuevas asignaturas que se impartan en inglés como para la promoción de las ya existentes entre el alumnado del Grado en Química. Los autores expresan su agradecimiento al Programa de Redes-I3CE de investigación en docencia universitaria del Vicerrectorado de Calidad e Innovación Educativa-Instituto de Ciencias de la Educación de la Universidad de Alicante (convocatoria 2020-2021).

The ExTech symposium series is the flagship event for sample preparation, analytical extraction and sample clean-up techniques. The series, started in 1999 by Prof. Janusz Pawliszyn (University of Waterloo, Canada), has been annually held around the world. ExTech has become a unique and vital medium for the exchange of information and ideas in the growing field of sample preparation. This Symposium is focused on the fundamentals, developments, and new technologies of extraction and sample preparation in different areas of analytical sciences including new extraction phases and technologies, remote sensing, in-vivo analysis, mili/microfluidics, lab-on-a-chip, diagnostic tool, new applications, etc. The XXIII International Symposium on Advances in Extraction Technologies is celebrated in a virtual modality and consists of a three-day e-meeting between the 30th June and the 2nd July 2021.

Los indicadores académicos de la signatura Química de las Disoluciones del Grado en Ciencias del Mar de la Universidad de Alicante son significativamente inferiores al promedio de la titulación. Este trabajo continúa con el estudio comenzado en la red del año pasado, implementando las nuevas estrategias docentes y analizando la satisfacción del alumnado con las mismas. Con este fin, se ha distribuido una encuesta al alumnado del curso académico 2020-2021 de Química de las Disoluciones del Grado en Ciencias del Mar de la Universidad de Alicante. A través de las encuestas se pretende conocer la opinión de los alumnos y alumnas de las nuevas metodologías docentes implantadas durante este curso. Además, estas nuevas estrategias se adaptan a la nueva situación generada por la pandemia asociada a la COVID-19, ya que se fomenta el trabajo no presencial tanto en las clases de teoría como en las de prácticas. La información obtenida del alumnado junto con las reflexiones sobre la misma del profesorado que constituye esta red puede ser de gran utilidad para mejorar los indicadores académicos y el proceso de enseñanza-aprendizaje en la asignatura de Química de las Disoluciones del Grado en Ciencias del Mar de la Universidad de Alicante.

An analytical methodology based in the combination of Thin Film Microextraction with Laser-induced Breakdown Spectroscopy (TFME-LIBS) was investigated, for the first time, for detection of Cu, Cr, Ni and Pb in aqueous solutions. In this methodology, the analytes were extracted in a thin film of adsorbent material deposited on a solid support, which was introduced in the sample to analyse. After extraction, the analytes retained in the adsorbent were analysed by LIBS. In order to obtain adsorbent films useful for the microextraction step, two different experimental procedures for film generation, denoted as Drop Casting Deposition and Mould Deposition, were evaluated. In both cases, graphene oxide was used as adsorbent material. The mould deposition procedure was found to produce more homogeneous graphene oxide layers, leading to more uniform distribution of the adsorbed analytes on the graphene oxide surface. Experimental parameters affecting the TFME procedure, such as the adsorbent amount and extraction time, were studied. Under optimum microextraction conditions, the analytical figures of merit of the proposed TFME-LIBS method were evaluated, leading to limits of detection ranging from 41 μg kg−1 and 52 μg kg−1. Method trueness, evaluated from the analysis of a real sample of bottle water, led to recovery values about 70%, indicating the existence of strong matrix effects probably due to the presence of major cations in the bottle water. After 50% dilution of the sample with deionized water, recoveries values improved to 100%–108%. This work was supported by the Spanish Ministry of Economy and Competitiveness [CTQ2016-79991-R], the Regional Government of Valencia (Spain) [PROMETEO/2013/038 and PROMETEO/2018/087]; and the University of Alicante [UAUSTI17-04 and UAUSTI18-04]. L. Ripoll is grateful to the Ministry of Economy and Competitiveness for her PhD fellowship (FPI-MICINN (BES-2012-058759)).

Las medidas establecidas para frenar la transmisión del virus COVID-19 han incorporado un nuevo modelo de docencia dual en las aulas del Grado en Nutrición Humana y Dietética de la Universidad de Alicante. La imposibilidad de llevar a cabo prácticas presenciales para el abordaje del estudio teórico-práctico del contenido de la valoración del estado nutricional, relacionado con la composición corporal, ha suscitado que se plantee una experiencia educativa innovadora. Esta experiencia trata de implementar una experiencia educativa innovadora, mediante la utilización de las TIC, y que el alumnado de Fundamentos de Alimentación y Nutrición, y Nutrición en la Actividad Física y el Deporte sean capaces de adquirir las competencias teórico-prácticas en materia de composición corporal. Para ello, se planteó una evaluación mediante cuestiones relacionadas con competencias concretas en relación con la composición corporal y la cineantropometría, a partir de un cuestionario online. Los resultados mostraron que tanto el alumnado de Fundamentos de Alimentación y Nutrición, como el de Nutrición en la Actividad Física y el Deporte, tuvieron una adecuada adquisición de las competencias. Por lo tanto, parece que la implementación de la experiencia educativa innovadora desarrollada, ha tenido buena acogida entre el alumnado y ha contribuido positivamente con la adquisición de competencias del alumnado.

In this study, a sensitive and matrix-effect free analytical method for Cd determination in engine oils and fuel samples by dispersive liquid-liquid microextraction with electrothermal atomic absorption spectrometry has been successfully developed. The extractant solvent used for the microextraction procedure was a magnetic ionic liquid (MIL) (i.e., bis(1-ethyl-3-methylimidazolium) tetrathiocyanatocobaltate (II) [Emim]2[Co(SCN)4]), which presents a paramagnetic property, and allows an easy phase separation using a magnet. In order to eliminate the well-known drawbacks of direct introduction of MIL in the graphite furnace, a back-extraction procedure was performed to transfer the analyte into an aqueous phase. The main experimental factors affecting the extraction of Cd (i.e., amount of sample and MIL, extraction and back-extraction time and concentration and amount of nitric acid) were optimized using a multivariate analysis consisting in two steps: a Plackett-Burman design followed by a circumscribed central composite design. Under optimum conditions (i.e., amount of sample: 6.2 g; amount of MIL: 119 mg; extraction time: 1 min; amount of nitric acid: 200 mg; nitric acid concentration: 1 mol L-1 and back-extraction time: 1 min), the proposed analytical method was validated and successfully used to analyze three real-world samples (i.e., used engine oil, gasoline and diesel). The three samples were spiked at two levels (i.e., 10 and 20 μg kg-1 of Cd for used engine oil and 1 and 3 μg kg-1 of Cd for gasoline and diesel). RSD and recovery values were within the range of 6–11% and 95–110%, respectively. The authors would like to thank the Spanish Government (projects n. CTQ2016-79991-R and PGC 2018-098363-100), Fundación Séneca (Project n. 19888/GERM/15) and European Union (FEDER funds) for the financial support.

A new, inexpensive and easy to use 3D printable device was developed for nephelometric and fluorimetric determination. Its applicability was tested for the quantification of quinine in tonic drinks and sulfate in natural water with good analytical accuracy. In this way, sulfate determination was carried out by nephelometry using a red LED, while quinine was determined using a blue LED by fluorimetry. A smartphone camera was used to take the pictures and afterwards transform them into the RGB color space using the software ImageJ by a personal computer. The linear range was 2.0-50.0 mg L-1for sulfate with a LOD of 0.13 mg L-1, and the corresponding quantification limit (LOQ) was 0.43 mg L-1. The linear range for quinine was from 0.42 to 3.10 mg L-1. The LOD and LOQ were 0.11 mg L-1and 0.38 mg L-1, respectively. Fil: Vidal, Ezequiel Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; Argentina Fil: Lorenzetti, Anabela Silvana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Biología Agrícola de Mendoza. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Instituto de Biología Agrícola de Mendoza; Argentina Fil: Aguirre, Miguel Ángel. Universidad de Alicante; España Fil: Canals, Antonio. Universidad de Alicante; España Fil: Domini, Claudia Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; Argentina

A new, fast, simple, and environmentally friendly analytical method has been developed to determine six siloxanes in water samples: octamethyltrisiloxane, octamethylcyclotetrasiloxane, decamethyltetrasiloxane, decamethylcyclopentasiloxane, dodecamethylpentasiloxane and dodecamethylcyclohexasiloxane. The analytical method consists of magnetic solid‐phase extraction employing graphene oxide/Fe3O4 as sorbent for the separation and preconcentration of siloxanes prior to GC–MS determination. The extraction procedure was optimized by means of a Plackett‐Burman design. Under the optimized extraction conditions (graphene oxide/Fe3O4, 20 mg; extraction time, 10 min; eluent volume, 0.5 mL ACN; elution time, 2.5 min; sample volume, 20 mL), the method rendered repeatability levels with a relative standard deviation between 9 and 20% (n = 6, 10 μg/L). Methodological limits of detection ranged from 0.003 to 0.1 μg/L. The linearity of the method was studied between the methodological limit of quantification and 100 μg/L, obtaining correlation coefficient values between 0.990 and 0.999. The applicability of the method was assessed by analyzing drinking, river and wastewater samples. Relative recovery values ranged between 70 and 120% (1 and 60 μg/L spiking level) showing that the matrix had a negligible effect on extraction. Finally, the greenness of this method was confirmed by the semiquantitative Eco‐Scale metrics. The authors would like to thank “Vicerrectorado de Investigación y Transferencia de Conocimiento” of the University of Alicante (UAUSTI16-04), the Ministry of Science and Innovation of Spain (project no. CTQ2011-23968), the Ministry of Economy, Industry and Competitiveness of Spain (project no. CTQ2016-79991-R, AEI/FEDER, UE) for the financial support. L. Costa thanks the Capes Foundation within the Ministry of Education in Brazil (Process 99999.012013/2013-07).

The chemical characterization of paint material is paramount for the understanding of painting techniques, provenance studies and for assessing conservation strategies. In particular, the chemical characterization of both the organic and inorganic fraction of lakes is fundamental to assess the technologies used in their production. In this short note, we present a pilot study by comparing several micro-destructive and non-destructive methods for the comprehensive characterization of the organic and inorganic fraction of reference madder lakes. In the final procedure, the chromophores-containing molecules were separated using a sample preparation procedure based on acid hydrolysis and solvent extraction, and analysed by high-pressure liquid chromatography with UV-Vis detector (HPLC-UV/Vis). Laser induced breakdown spectroscopy (LIBS) and X-Ray Fluorescence (XRF) were used for the study of the elemental composition. Multispectral Imaging was also applied in order to evaluate its potentialities to distinguish amongst different red lakes. The final multi-technique method allowed for the characterization of both organic and inorganic fraction from the same lake micro sample.

A new portable electrochemical sensor based on 4-aminobenzoic acid-modified herringbone carbon nanotubes (hCNTs-4ABA/Au-IDA) has been developed for the simultaneous determination of ascorbic acid (AA) and uric acid (UA) in physiological fluids. AA and UA were quantified by chronoamperometry at 0.1 and 0.32 V, respectively, in phosphate buffer solution (PBS 0.25 M, pH 7.0). Significant results were obtained for the separate quantification of AA and UA, with a limit of detection (LOD) of 0.65 μM for both analytes, and sensitivities of (9.0 ± 0.4) A g−1 mM−1 and (8.8 ± 0.3) A g−1 mM−1 for AA and UA, respectively. Repeatability was studied at 50 μM for AA and UA, providing relative standard deviations (RSD) lower than 9%. Additions of glucose, dopamine and epinephrine did not interfere with the AA and UA determination. Furthermore, UA did not interfere with AA determination at 0.1 V, although AA additions increased the current recorded at 0.32 V. The method has been successfully applied to human urine, perspiration and serum samples, without significant matrix effects, which allows for the use of an external calibration and the analysis of all the matrices investigated. This work is supported by the Generalitat Valenciana (Prometeo2013/038) and by the Ministerio de Economia y Competitividad (MAT2016–76595-R). A. Abellán also thanks the Generalitat Valenciana for her fellowship.

A simple, fast, sensitive and green pretreatment method for determination of Cd, Co, Hg, Ni, Pb and V in oral and parenteral drug samples using inductively coupled plasma optical emission spectrometry (ICP OES) has been developed. According to United States Pharmacopoeia (USP), those metals must be reported in all pharmaceutical products for quality control evaluation (i.e., elemental impurities from classes 1 and 2A of USP Chapter 232). To improve the analytical capabilities of ICP OES, a dispersive liquid-liquid microextraction (DLLME) has performed using a safe, cheap and biodegradable deep eutectic solvent (DES) as extractant solvent (a mixture of 2:1 molar ratio of DL-menthol and decanoic acid). Seven parameters affecting the microextraction efficiency have carefully optimized by multivariate analysis. Under optimized conditions, the DES-based DLLME-ICP OES procedure improved limit of quantitation (LOQ) values on range from 12 to 85-fold and afforded an enrichment factor on average 60-times higher than those obtained to direct ICP OES analysis. Consequently, LOQ values for Cd, Co, Hg, Ni, Pb and V have been on average 10-times lower than target limits recommended for drugs from parenteral route of administration. Trueness has evaluated by addition and recovery experiments following USP recommendations for three oral drug samples in liquid dosage form and three parenteral drugs. Recovery and RSD values have been within the range of 90-109% and 1-6%, respectively. All analytes were below the repectives LOQ values, hence, lower than the limits proposed by USP Chapter 232. The authors are grateful to the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq, grants no. 141634/2017-0, 202722/2019-8, 305201/2018-2 and 428558/2018-6), the Ministry of Economy and Competitiveness of Spain (PGC2018-096616-B-I00) the Regional Government of Valencia (Spain) (PROMETEO/2018/087, ACIF/2020/186), and University of Alicante (VIGROB-316FI) for the financial support, Agilent Technologies Inc. for the loan of the ICP OES spectrometer, and Ingeniatrics for the OneNeb® Series 2 provided. This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) - Finance Code 001. The authors extend their appreciation to Ministry of Science, Innovation and Universities for granting the Spanish Network of Excellence in Sample Preparation (RED2018-102522-T). This article is based upon work from the Sample Preparation Study Group and Network, supported by the Division of Analytical Chemistry of the European Chemical Society.

Complexation-mediated electromembrane extraction (EME) of highly polar basic drugs (log P < −1) was investigated for the first time with the catecholamines epinephrine, norepinephrine, and dopamine as model analytes. The model analytes were extracted as cationic species from urine samples (pH 4), through a supported liquid membrane (SLM) comprising 25 mM 4-(trifluoromethyl)phenylboronic acid (TFPBA) in bis(2-ethylhexyl) phosphite (DEHPi), and into 20 mM formic acid as acceptor solution. EME was performed for 15 min, and 50 V was used as extraction voltage across the SLM. TFPBA served as complexation reagent, and selectively formed boronate esters by reversible covalent binding with the model analytes at the sample/SLM interface. This enhanced the mass transfer of the highly polar model analytes across the SLM, and EME of basic drugs with log P in the range −1 to −2 was shown for the first time. Meanwhile, most matrix components in urine were unable to pass the SLM. Thus, the proposed concept provided highly efficient sample clean-up and the system current across the SLM was kept below 50 μA. Finally, the complexation-mediated EME concept was combined with ultra-high performance liquid chromatography coupled to tandem mass spectrometry and evaluated for quantification of epinephrine and dopamine. Standard addition calibration was applied to a pooled human urine sample. Calibration curves using standards between 25 and 125 μg L−1 gave a high level of linearity with a correlation coefficient of 0.990 for epinephrine and 0.996 for dopamine (N = 5). The limit of detection, calculated as three times signal-to-noise ratio, was 5.0 μg L−1 for epinephrine and 1.8 μg L−1 for dopamine. The repeatability of the method, expressed as coefficient of variation, was 13% (n = 5). The proposed method was finally applied for the analysis of spiked pooled human urine sample, obtaining relative recoveries of 91 and 117% for epinephrine and dopamine, respectively. The authors would like to thank the Spanish Ministry of Science and Innovation (project n. CTQ2011-23968) and Generalitat Valenciana (Spain) (projects n. GVA/2014/096 and PROMETEO/2013/038) for the financial support. E. Fernández thanks Spanish Ministry of Education for her FPU grant (FPU13/03125) and mobility grant (EST15/00074).

Magnetic dispersive solid-phase extraction (MDSPE) is combined with electrochemical detection by using a screen-printed carbon electrode modified with gold nanoparticles to determine lead(II). A zeolite-based magnetic composite was used as sorbent during sample preparation, thus combining the unique properties of zeolites as sorbent materials with the remarkable advantages provided by magnetic materials. Three different zeolite-based magnetic composites were initially investigated and characterized. ZSM-5/Fe2O3 treated with HNO3 (ZSM-5/Fe2O3(tr)) was finally selected as sorbent. Lead was extracted from urine samples using ZSM-5/Fe2O3(tr). After extraction, the phases were separated by using an external magnet. Subsequently, the magnetic composite carrying the analyte was directly deposited onto the working electrode of a modified screen-printed carbon electrode for final electrochemical detection. Thereby, the elution and detection of Pb(II) were carried out in a single step. A multivariate approach was employed to optimize the experimental parameters affecting extraction. Under optimized conditions and at a typical working potential of −0.23 V (vs. Ag pseudo-reference electrode), response is linear in the 0 to 25 μg L−1 Pb(II) concentration range. The empirical limit of detection ranged from 1.0 to 2.0 μg L−1. The method was used to analyze Pb(II)-spiked urine samples, and apparent recoveries ranged between 99 and 107%, with coefficients of variation of

A new multinebulizer has been employed for wear metal (e.g., Cd, Cr, Cu, Fe, Mn, Ni, and Pb) determination in used lubricating oils. To this end, a multinebulizer-based analytical methodology combined with on-line standard dilution analysis (on-line SDA) and inductively coupled plasma optical emission spectrometry (ICP OES) (multinebulizer/SDA/ICP OES) has been proposed, which is able to overcome typical limitations related to organic sample analysis by ICP-based techniques. This is accomplished by the simultaneous introduction of organic samples and aqueous calibration standards, with a minimal sample pretreatment (i.e., dilution). The multinebulizer/SDA/ICP OES combination allows the determination of Cd, Cr, Cu, Fe, Mn, Ni and Pb in used lubricating oils with a limit of detection of 20, 10, 6, 20, 4, 30 and 200 ng g−1, respectively. The subsequent analysis of spiked commercial lubricating oil samples has led to recovery values which range from 91 to 108%. The efficiency of the proposed methodology has been checked by comparing its results with values obtained with conventional standard addition calibration and both limits of detection and recovery values were of the same order of magnitude. The proposed analytical methodology has the main advantage of ease of operation, as time and cost of analysis are reduced and the use of organic calibration standards is also avoided. Hence, the synergistic association multinebulizer/SDA is a simple, fast, relatively economic, environmentally friendly, direct and reliable method of wear metal monitoring in used lubricating oils by ICP OES. The authors would like to thank the Ministry of Economy and Competitiveness of Spain (project no. CTQ2016-79991-R, AEI/FEDER, UE) for the financial support, Agilent Technologies Inc. for the loan of the ICP OES spectrometer, and Ingeniatrics for the MultiNeb® provided.

The continuous release of anthropogenic pollutants into marine environment increases the needs for the development of analytical procedures for their accurate determination in many sample types. Sound strategies for seafood safety monitoring call for measurement systems capable of producing comparable analytical results with demonstrated quality. Method validation, traceability, and uncertainty of analytical results are the three milestones to assess data quality. Some trace elements are essential for biological structures, but they can become toxic at concentrations beyond those necessary for their functions; others are toxic even at very low levels. Their accurate determination in reference samples serves as an important step in seafood safety control and pollution monitoring. Isotope dilution inductively coupled plasma-mass spectrometry (ID ICP-MS) has been applied for the determination of the total mass fractions of five trace elements (Cd, Cu, Hg, Pb, and Zn) and methyl mercury (MeHg) in marine biota candidate reference material IAEA-476. Because of the complex matrix of the sample and the expected spectral interferences, special care was taken for the validation of the applied methodology, particularly for its measurement step. Reference isotopic measurements were carried out by sector field inductively coupled plasma-mass spectrometer (ICP-SFMS). The entire ID ICP-SFMS measurement procedure was described by mathematical modeling and the combined uncertainty of measurement results was estimated. All factors influencing the final results and isotopic equilibrium were systematically investigated. This included the procedural blank, the moisture content in biota samples, and all factors affecting the blend ratio measurements (i.e., instrumental background, spectral interferences, dead time, mass discrimination effects, and the repeatability of measured isotope ratios). Modeling of the entire measurement procedure and the use of appropriate certified reference materials (CRM) enable to assure the traceability of obtained values to the International System of Units (SI). Finally, the developed procedure has been successfully applied in the process of the certification of the International Atomic Energy Agency (IAEA) certified reference material for trace elements and MeHg mass fractions in fish homogenate sample. The excellent agreement between obtained results in the present study and those derived from the IAEA certification campaign for trace elements and MeHg in the same sample matrix further validated the reference methods developed in the IAEA.

La presente Red examina desde la perspectiva del alumnado, los factores motivacionales y las actitudes generales en el aprendizaje del inglés en el grado en Química en la Facultad de Ciencias de la Universidad de Alicante. Este estudio se basa en la recogida de información tanto cualitativa como cuantitativa de las asignaturas de “Calidad en el laboratorio analítico”, “Cinética química” y “Química orgánica avanzada” durante el curso 2019-2020. El análisis de los resultados revela interesantes diferencias en la percepción del alumnado en relación con los factores motivacionales y la actitud individual de los y las participantes frente a la docencia en inglés. La información obtenida en este estudio de los y las estudiantes junto con las reflexiones sobre la misma del profesorado que constituye la Red puede ser de gran utilidad para la Facultad de Ciencias de la Universidad de Alicante tanto para la implantación de nuevas asignaturas que se impartan en inglés, así como para la promoción de las ya existentes entre el alumnado del grado en Química. Los autores expresan su agradecimiento al Programa de Redes-I3CE de investigación en docencia universitaria del Vicerrectorado de Calidad e Innovación Educativa-Instituto de Ciencias de la Educación de la Universidad de Alicante (convocatoria 2019-2020).

Se presenta un proyecto de red vertical modalidad B en el que diversas asignaturas de los dos primeros y únicos cursos del nuevo Grado de Gastronomía y Artes Culinarias de la Universidad de Alicante se implicarán para la Innovación e Investigación en Docencia Universitaria. A consecuencia de los resultados obtenidos el curso anterior de la Red Docente con código 4460 y título “Detección de necesidades en competencias transversales, coordinación y evaluación de acciones educativas en primer curso del nuevo Grado de Gastronomía y Artes Culinarias de la Universidad de Alicante”, se detectaron carencias notables en relación a dos habilidades del alumnado en comunicación oral y escrita, las cuales repercutieron negativamente en sus calificaciones. Por ello, en este curso académico se plantea el presente proyecto con objeto de diseñar, implementar y evaluar de manera cooperativa entre el profesorado de primer y segundo curso del Grado, nuevas estrategias de enseñanza-aprendizaje e innovadores materiales para que el alumnado pueda acceder al mismo desde nuevo ingreso facilitando una guía en la preparación de sus trabajos escritos y presentaciones orales mejorando sus calificaciones y competencias transversales para su inclusión en el mundo profesional.

En las ciencias sanitarias es importante el aprendizaje de las tecnologías de la información y comunicación, ya que es un sector en constante evolución y desarrollo. Por ello, el objetivo del presente trabajo fue implementar, dentro del proceso de enseñanza-aprendizaje en estudiantes del Grado en Nutrición Humana y Dietética, estrategias centradas en el desarrollo de competencias relacionadas con la investigación. 27 estudiantes desarrollaron las estrategias propuestas durante el curso 2019-20. Como resultados, se obtuvo que el grupo de estudiantes en el que se implementó la acción innovadora, basada en estrategias de aprendizaje enfocadas a la investigación, adquirieron en mayor grado, competencias transversales relacionadas con este campo. Asimismo también obtuvieron mejores calificaciones, estadísticamente significativas, cuando se compararon los resultados obtenidos en los trabajos finales de la asignatura de Nutrición en la Actividad Física y del Deporte. De este modo, se podría concluir que la implementación de esta acción innovadora parece mejorar la adquisición de competencias relacionadas con la investigación y presenta resultados positivos en el rendimiento académico en los estudiantes del Grado en Nutrición Humana y Dietética. Sin financiación No data WoS No data Scopus 70 SPI – ICEE (2018), 55/105 General – Editoriales españolas UEM

The combination of electrospray deposition with laser-induced breakdown spectroscopy (ESD-LIBS) was investigated as a potential approach to the detection and quantification of Zn, Cd, Cr and Ni, at trace levels, in aqueous samples. In this analytical procedure, the aqueous samples were first converted into solids in an electrospray system. To this end, micro-volumes of liquids were electro-sprayed onto a heated substrate, leading to the generation of solid residues. Afterwards, the as-obtained residues were analysed by LIBS. Three calibration methodologies were tested with the proposed ESD-LIBS methodology, namely external calibration, conventional standard addition calibration and on-line standard addition calibration. In all cases, the analytical features of the ESD-LIBS method were assessed. The obtained limits of detection ranged from 9 μg kg−1 to 57 μg kg−1, depending on the element and on the calibration modality used. Method trueness, evaluated from the analysis of a real sample of tap water, was highly dependent on the calibration method. The use of external calibration led to recovery values in the range of 18–123%, indicating the existence of strong matrix effects. This drawback was overcome with the application of conventional standard addition and on-line standard addition calibration modalities, for which recovery values were improved to the ranges 91–110% and 90–105%, respectively. Among them, the use of on-line standard addition provides a sensitive and accurate methodology with possibilities of automation. L. Ripoll is grateful to the Ministry of Economy and Competitiveness for her PhD fellowship (FPI-MICINN (BES-2012-058759)).

A rapid and portable analytical methodology has been developed for ibuprofen (IBU) quantification in commercial dosage tablets using a spectrometric smartphone-based system. The analytical methodology employs point-of-use approaches both for sample preparation and detection, demonstrating its potential utility for portable quality control of pharmaceutical products. In this work, IBU is dissolved in methanol and then treated with a Co(II) aqueous solution, forming a blue complex which is extractable by dispersive liquid-liquid microextraction. Then, the sample’s absorption spectrum is directly measured by a spectrometric smartphone-based system using cartridge made of polyoxymethylene for solvent compatibility. The main experimental factors affecting the dispersive liquid-liquid microextraction of Co-IBU complex were optimized using a multivariate analysis. Under optimized conditions, a working range between 20 and 80 μg mL−1 was obtained with a correlation coefficient of 0.996 for 5 calibration points. The limit of detection and limit of quantification obtained were 4 and 12 μg mL−1, respectively. The performance of the proposed methodology was evaluated in commercial tablet dosage forms, and the results demonstrate the ability of the method to determine IBU in samples representative of those used in real-world quality control applications. Recovery values between 97% and 105% were obtained, which are comparable to those obtained via standard titrimetric methodology. The authors would like to acknowledge the National Science Foundation for their support of this work via Grant no. CBET 12-64377. M.A.A. is grateful to Generalitat Valenciana (Spain) (APOSTD/2016/076) for his Post-Doctoral fellowship and the financial support from the European Social Fund (ESF). K.D.L. is supported by a Ruth L. Kirschstein Pre-Doctoral Fellowship (NIH F30AI122925).

This review focuses on the combination of elemental detection techniques with liquid-phase microextraction (LPME), namely, single drop microextraction, hollow fiber based liquid-phase microextraction, dispersive liquid-liquid microextraction, and related techniques. General features of different microextraction procedures, historical overview and automation of LPME are described and compared, along with examples of new developments and applications presented to demonstrate its potential for trace and ultra-trace metal analysis. Furthermore, potential applications and an outlook on the combination of LPME and elemental detection techniques for inorganic analysis are presented. The authors would like to thank the Spanish Ministry of Economy and Competitiveness and European Union (FEDER funds) (project n. CTQ2016-79991-R) for the financial support. P. Baile also thanks Ministry of Education, Culture and Sports for her FPU grant (FPU14/04589).

Gold interdigitated microelectrodes (Au-IDA) modified with either graphene flakes exfoliated using flavin mononucleotide (FMN) (Gr-FMN) or graphene flakes and platinum nanoparticles (Pt-Gr-FMN) have been studied in the oxidation of uric acid (UA). An electrochemical method for the detection and quantification of UA in phosphate buffer solution at physiological pH (PBS, 0.25 M, pH 7) in the absence and presence of ascorbic acid (AA) has been studied by cyclic voltammetry. The quantification of UA was investigated by cyclic voltammetry, presenting an oxidation peak at 0.99 V with both modified electrodes. Linearity range of 60–578 μM and 60–345 μM has been found for Gr-FMN/Au-IDA and Pt-Gr-FMN/Au-IDA electrodes, respectively. Limits of detection of 18 μM were obtained for both electrodes, and the repeatability was studied at 177 μM providing 4% and 8% for Gr-FMN/Au-IDA and Pt-Gr-FMN/Au-IDA, respectively. AA interference has been studied by cyclic voltammetry, showing two clearly separated oxidation peaks, at 0.99 V for UA oxidation and at 0.74 V for Gr-FMN/Au-IDA and 0.70 V for Pt-Gr-FMN/Au-IDA for AA oxidation. Linearity range has been studied in presence of 250 μM AA obtaining a working range of 60–578 μM for Gr-FMN/Au-IDA electrode and of 60–288 μM with Pt-Gr-FMN/Au-IDA electrode. Limits of detection remain at 18 μM for both electrodes and the repeatability was studied at 177 μM providing 8% and 14% for Gr-FMN/Au-IDA and Pt-Gr-FMN/Au-IDA electrodes respectively. This work is supported by the Generalitat Valenciana (Prometeo2013/038) and by the Spanish Ministerio de Economía y Competitividad (MAT2013-42007-P). We also acknowledge partial funding of this work by Ministerio de Economía y Competitividad and the European Regional Development Fund (ERDF) through projectMAT2015-69844-R aswell as by Plan de Ciencia, Tecnología e Innovación 2013–2017 del Principado de Asturias and ERDF (project GRUPIN14-056). A. Abellán-Llobregat also thanks the Generalitat Valenciana for her fellowship and M. Ayán-Varela acknowledges his predoctoral contract (FPI) from Ministerio de Economía y Competitividad.

A novel and environment friendly analytical method is reported for total chromium determination and chromium speciation in water samples, whereby tungsten coil atomic emission spectrometry (WCAES) is combined with in situ ionic liquid formation dispersive liquid–liquid microextraction (in situ IL-DLLME). A two stage multivariate optimization approach has been developed employing a Plackett–Burman design for screening and selection of the significant factor involved in the in situ IL-DLLME procedure, which was later optimized by means of a circumscribed central composite design. The optimum conditions were complexant concentration: 0.5% (or 0.1%); complexant type: DDTC; IL anion: View the MathML sourcePF6−; [Hmim][Cl] IL amount: 60 mg; ionic strength: 0% NaCl; pH: 5 (or 2); centrifugation time: 10 min; and centrifugation speed: 1000 rpm. Under the optimized experimental conditions the method was evaluated and proper linearity was obtained with a correlation coefficient of 0.991 (5 calibration standards). Limits of detection and quantification for both chromium species were 3 and 10 µg L−1, respectively. This is a 233-fold improvement when compared with chromium determination by WCAES without using preconcentration. The repeatability of the proposed method was evaluated at two different spiking levels (10 and 50 µg L−1) obtaining coefficients of variation of 11.4% and 3.6% (n=3), respectively. A certified reference material (SRM-1643e NIST) was analyzed in order to determine the accuracy of the method for total chromium determination and 112.3% and 2.5 µg L−1 were the recovery (trueness) and standard deviation values, respectively. Tap, bottled mineral and natural mineral water samples were analyzed at 60 µg L−1 spiking level of total Cr content at two Cr(VI)/Cr(III) ratios, and relative recovery values ranged between 88% and 112% showing that the matrix has a negligible effect. To our knowledge, this is the first time that combines in situ IL-DLLME and WCAES. The authors would like to thank the Spanish Ministry of Science and Innovation (Project no. CTQ2011-23968), Spanish Ministry of Education, Culture and Sport (Project no. PHB2010-0018-PC), Generalitat Valenciana (Spain) (Project no. ACOMP/2013/072), and Coordenação de Aperfeiçoamento de Pessoal de Nível Superior in Brazil (Grant CAPES-DGU n. 243/11). L. Vidal also thanks the Spanish Ministry of Education, Culture and Sport for her travel Grant (HBP-2010-0030) and S.G. Silva is grateful to the Grant 2011/13288-7, São Paulo Research Foundation (FAPESP).

A novel, simple, fast, sensitive and environmentally friendly approach is presented to determine cadmium in urine samples, combining magnetic dispersive solid-phase extraction (MDSPE) for sample preparation and screen-printed carbon electrodes (SPCEs) for square-wave anodic stripping voltammetry. This association involves the miniaturization of sample preparation and measurement process. Firstly, cadmium was extracted directly from urine samples employing a ZSM-5/Fe2O3, then, the composite enriched with cadmium was deposited onto the SPCE and finally covered with a suitable electrolyte for electrochemical detection. Thereby, the elution and detection of cadmium were carried out in a single step. To optimize experimental parameters affecting MDSPE, a two-step multivariate strategy has been employed. The method has been evaluated under optimized extraction/elution conditions (i.e., type of sorbent, ZSM-5/Fe2O3; amount of sorbent, 10 mg; sample pH, 6.8; extraction time, 5.5 min; and HCl concentration, 0.5 M) using standard addition calibration. Standard addition calibration curves gave a good linearity in the range from 0 to 30 μg L−1 with correlation coefficients ranging from 0.997 to 0.998 (N = 7). The limit of detection, evaluated empirically and statistically, ranged from 0.5 to 1.0 μg L−1 and from 0.4 to 0.8 μg L−1, respectively, which are lower than the threshold level established by the Ministry of Labour and Social Affairs (Spain) and World Health Organization for normal cadmium content in urine (i.e., 3.4 and 4.0 μg L−1, respectively). The repeatability of the proposed method was evaluated at 5 and 20 μg L−1 spiking levels obtaining coefficients of variation ranged between 12 and 15% (n = 6). A certified reference material (REC-8848/Level II) was analyzed to assess method accuracy finding 92% and 1.3 μg L−1 as the recovery (trueness) and standard deviation values, respectively. Finally, the method was applied to spiked urine samples, obtaining good agreement between spiked and found concentrations (recovery ranged from 89 to 98% and CV values ranged from 7% to 14%). Therefore, this is a new and successful contribution to the portable total analytical systems. The authors would like to thank the Generalitat Valenciana (Spain) (project n. PROMETEO/2018/087) and the Spanish Ministry of Economy and Competitiveness and European Union (FEDER funds) (project n. CTQ2016-79991-R) for the financial support. P. Baile also thanks Ministry of Education, Culture and Sports for her FPU grant (FPU14/04589).

INTRODUCCIÓN: En España, un tercio de los estudiantes universitarios presentan sobrepeso u obesidad. Una alimentación saludable, basada en la dieta mediterránea, junto con ejercicio físico regular, mejora parámetros de composición corporal y condición física. OBJETIVO: Estudiar la relación entre adherencia a la dieta mediterránea y variables específicas de composición corporal y condición física en estudiantes universitarios de Nutrición Humana y Dietética (NHyD). METODOLOGÍA: Estudio piloto en el que participaron 20 estudiantes del grado de NHyD. Se estudiaron variables de alimentación, utilizando el PREDIMED; de composición corporal, mediante una antropometría; y de condición física a través de diferentes pruebas. Se realizaron estadísticos descriptivos y correlaciones. RESULTADOS: Los resultados del PREDIMED fueron muy homogéneos, presentando todos una adherencia óptima (10,24±1,01). En relación a la composición corporal, la muestra presentaba Normopeso (23,54 ±2,78) y un porcentaje de grasa corporal de 10,9±2,66 en hombres y 12,83±1,47 en mujeres. Sólo se estableció una correlación significativa entre la adherencia a la dieta mediterránea y el test Side Bridge (R=0,049,p=0,710) en hombres. CONCLUSIÓN: No se observaron relaciones entre los hábitos alimentarios y las variables de composición corporal y condición física a excepción de una prueba de fuerza en el caso de los varones participantes en el estudio.

El objetivo del Grado de Gastronomía y Artes Culinarias es la formación de profesionales que puedan comprender y ejercer en cualquier situación profesional relacionada con las ciencias gastronómicas. El primer curso contiene 42 créditos de formación básica y 18 de asignaturas obligatorias. Tras la superación del mismo, el alumno debe haber adquirido, competencias transversales tales como comprender textos en idioma extranjero, habilidades en informática y comunicación oral y escrita, destrezas en operaciones básicas de laboratorio y cálculos matemáticos sencillos. El presente trabajo tiene como objetivo detectar necesidades para coordinar, implementar y evaluar acciones educativas destinadas a la mejora de la calidad docente y el proceso enseñanza-aprendizaje. Se realizó un análisis de la situación inicial del alumnado que confirmó que más del 50% proviene de ciencias sociales y no tiene ningún conocimiento sobre laboratorio, entre otros. Además, se detectaron otras carencias tales como: insuficientes destrezas en informática, en comprensión de idioma extranjero y en la redacción de trabajos académicos. Con el fin de mejorar dichas carencias, se han llevado a cabo las siguientes acciones educativas: a) Lectura de un artículo científico en inglés, b) Aula invertida, c) Seminario sobre Excel, d) Seminario de laboratorio y cálculos, e) Habilidades en comunicación escrita, f) Presentación oral. Como resultado del presente proyecto se dispone de herramientas docentes que mejoran las calificaciones finales del alumnado.

El objetivo del Grado de Gastronomía y Artes Culinarias es la formación de profesionales que puedan comprender y ejercer en cualquier situación profesional relacionada con las ciencias gastronómicas. El primer curso contiene 42 créditos de formación básica y 18 de asignaturas obligatorias. Tras la superación del mismo, el alumno debe haber adquirido, competencias transversales tales como comprender textos en idioma extranjero, habilidades en informática y comunicación oral y escrita, destrezas en operaciones básicas de laboratorio y cálculos matemáticos sencillos. El presente trabajo tiene como objetivo detectar necesidades para coordinar, implementar y evaluar acciones educativas destinadas a la mejora de la calidad docente y el proceso enseñanza-aprendizaje. Se realizó un análisis de la situación inicial del alumnado que confirmó que más del 50% proviene de ciencias sociales y no tiene ningún conocimiento sobre laboratorio, entre otros. Además, se detectaron otras carencias tales como: insuficientes destrezas en informática, en comprensión de idioma extranjero y en la redacción de trabajos académicos. Con el fin de mejorar dichas carencias, se han llevado a cabo diferentes acciones educativas. Como resultado del presente proyecto se dispone de herramientas docentes que mejoran las calificaciones finales del alumnado.

We demonstrate a rapid, 2-step, and ultrasensitive assay approach for quantification of target protein molecules from a single droplet test sample. The assay is comprised of antibody-conjugated gold nanoparticles (AuNPs) that are “activated” when they are mixed with the test sample and bind their targets. The resulting liquid is passed through a microfluidic channel with a photonic crystal (PC) biosensor that is functionalized with secondary antibodies to the target biomarker, so that only activated AuNPs are captured. Utilizing recently demonstrated hybrid optical coupling between the plasmon resonance of the AuNP and the resonance of the PC, each captured AuNP efficiently quenches the resonant reflection of the PC, thus enabling the captured AuNPs to be digitally counted with high signal-to-noise. To achieve a 2-step assay process that is performed on a single droplet test sample without washing steps or active pump elements, controlled single-pass flow rate is obtained with an absorbing paper pad waste reservoir embedded in a microfluidic cartridge. We use the activate capture and digital counting (AC + DC) approach to demonstrate HIV-1 capsid antigen p24 detection from a 40 μL spiked-in human serum sample at a one thousand-fold dynamic range (1–103 pg mL−1) with only a 35-minute process that is compatible with point-of-care (POC) analysis. The AC + DC approach allows for ultrasensitive and ultrafast biomolecule detection, with potential applications in infectious disease diagnostics and early stage disease monitoring. This work is supported by the National Institutes of Health (NIH) R01 AI20683, F30AI122925, and the Carl Woese Institute for Genomic Biology postdoctoral fellowship.

Zeolites are ordered crystalline materials with a promising performance for a wide range of applications such as catalysis, petrochemistry, environmental remediation, and medicine, but have scarcely been evaluated in Analytical Chemistry. Their unique and fascinating properties such as their high surface area, high adsorption capacity and molecular selectivity, chemical and thermal stability, ion-exchange capacity, low cost extraction and synthesis, and their easy modification, which provides a wide range of zeolite-based materials, make zeolites potential sorbents for extraction procedures. Therefore, in this review, we provide an overview of the current status of zeolites and zeolite-based materials used in extraction and microextraction techniques with reference to recent applications and highlight some of the novel advances. The authors would like to thank the Spanish Ministry of Economy and Competitiveness and European Union (FEDER funds) (project no. CTQ2016-79991-R) for financial support. P. Baile also thanks the Ministry of Education, Culture and Sports for her FPU grant (FPU14/04589).