Overview of the novel sorbents available in solid-phase extraction to improve the capacity and selectivity of analytical determinations

Aquest article descriu els nous desenvolupaments en materials polimèrics que milloren l'extracció en fase sòlida (SPE) dels anàlits presents en mostres líquides. Se centra principalment en nous sorbents polimèrics, tant els comercialment disponibles com els sintetitzats per grups de recerca, amb propietats millorades per a l'extracció d'analits. Es descriuen diversos tipus de sorbents polimèrics, des dels que milloren la capacitat d'extracció (anomenats hypercrosslinked, amb elevada àrea superficial i hidrofilicitat) fins als que milloren la selectivitat del procés (els polímers d'empremta molecular [MIP] sintetitzats amb una cavitat específica per a l'analit d'interès) i també aquells que combinen ambdues propietats (coneguts com sorbents de mode mixt, que són sorbents d'elevada capacitat amb un grup d'intercanvi iònic que aporta la selectivitat en el procés d'extracció). També es presenten i es comparen resultats dels diversos sorbents quan s'apliquen a SPE d'analits en matrius dels camps d'aplicació analítics més rellevants.This article provides an overview of the most recent developments in polymer materials that improve the solidphase extraction (SPE) of analytes from liquid samples. The main focus is on new polymeric sorbents, both commercially available and “in-house” synthesized, whose enhanced properties allow suitable extraction. Several types of polymeric sorbents are described herein. Hypercrosslinked sorbents improve the capacity of the extraction process due to their large specific surface areas and balanced hydrophilicities. Molecularly imprinted polymers (MIPs) are synthesized with a specific cavity for the analyte of interest, improving extraction selectivity. Another type are mixed-mode sorbents that are high-capacity sorbents that contain an ion-exchange moiety that finetunes the selectivity of the extraction process. Finally, the results obtained when these sorbents are applied as SPE material to extract analytes in different liquid matrices are presented and comparatively discussed in the context of the most relevant analytical fields

Plan S y ecosistema de revistas españolas de ciencias sociales hacia el acceso abierto: amenazas y oportunidades

El Plan S promueve que todos los artículos derivados de investigaciones financiadas por las agencias que lo suscriben sean puestos en acceso abierto de forma inmediata, ya sea en revistas o en repositorios que cumplan con determinadas condiciones, a partir de enero de 2021. Ha sido promovido por Science Europe, una agrupación de agencias de financiación pública de la investigación a través de la cOAlition S, y ha publicado dos versiones que han generado un intenso debate académico en todo el mundo. Aunque ninguna agencia de investigación pública o privada del estado español se ha comprometido de momento a apoyar el Plan S, es interesante valorar como dicho Plan puede afectar al ecosistema de revistas científicas españolas. Se presentan los resultados del análisis de las revistas españolas de ciencias sociales que figuran en el SCImago Journal Rank y el cumplimiento que tienen de los requisitos que la cOAlition S ha descrito para que las revistas sean consideradas de acceso abierto de calidad. Dichos requisitos están relacionados con la apertura de los contenidos, el modelo de pago, aspectos técnicos y los derechos de autor. Se concluye que, aunque la mayor parte de las revistas cumplen los requisitos relativos a los contenidos abiertos, les quedan como retos los aspectos técnicos de máxima interoperabilidad y reutilización. Se recomienda a las revistas que tomen el Plan S como oportunidad y aprovechen para llevar a cabo una transformación digital plena

El plan S para acelerar el acceso abierto:contexto, retos y debate generado

Se analizan los principales elementos y características del Plan S, iniciativa de la cOAlition S, promovido desde Europa para acelerar el acceso abierto, al pedir a los investigadores que los artículos sufragados por un conjunto de agencias adheridas sean puestos a disposición inmediatamente una vez publicados, con una serie de requisitos a nivel de licencias. Dicho plan ha conllevado un encendido debate en el mundo académico entre defensores y detractores. A continuación, se sintetizan y categorizan los principales argumentos y puntos de vista que se han manifestado con-trarios a la iniciativa. Finalmente, se apuntan los principales retos que el Plan S tendrá para cumplir con sus objetivos

Risk Assessment Related to Atmospheric Polycyclic Aromatic Hydrocarbons in Gas and Particle Phases near Industrial Sites

Background: Inhalation is one of the main means of human exposure to polycyclic aromatic hydrocarbons (PAHs) because of their ubiquitous presence in the atmosphere. However, most studies have considered only PAHs found in the particle phase and have omitted the contribution of the gas-phase PAHs to the risk

Hypercrosslinked polymer microspheres decorated with anion- and cation-exchange groups for the simultaneous solid-phase extraction of acidic and basic analytes from environmental waters

Mixed-mode ion-exchange sorbents were introduced to improve the selectivity and retention of solid-phase extraction (SPE) sorbents,. Mixed-mode ion-exchange sorbents integrate reversed-phase chemistry with ion-exchange groups to promote favourable interactions with ionic species. Nevertheless, a need to extract analytes with acidic and basic properties simultaneously within the same SPE cartridge led to the introduction of novel amphoteric/zwitterionic sorbents, which incorporate cation- and anion-exchange moieties within the same functional group attached to the polymeric network. In the present study, the development, preparation and SPE evaluation of two novel hypercrosslinked zwitterionic polymeric sorbents, functionalised with either strong anion-exchange (SAX) and weak cation-exchange (WCX) or weak anion-exchange (WAX) and strong cation-exchange (SCX) groups (namely HXLPP-SAX/WCX and the HXLPP-WAX/SCX), is presented for the simultaneous retention of acidic and basic compounds. The sorbents were prepared by a precipitation polymerisation route which yielded poly(divinylbenzene-co-vinylbenzylchloride) as a precursor polymer; subsequently, the precursor polymer was hypercrosslinked, to increase the specific surface areas and capacities of the sorbents, and then functionalised to impart the zwitterionic character. The HXLPP-SAX/WCX sorbent was decorated with quaternised sarcosine groups and the HXLPP-WAX/SCX sorbent was decorated with taurine moieties. The SPE parameters were optimised to exploit the ionic interactions between compounds and the functional groups. The optimal conditions involve a washing step to remove the compounds retained by hydrophobic interactions, thus increasing the selectivity. The optimised SPE protocol used the quaternised sarcosine-based sorbent followed by liquid chromatography and tandem mass spectrometry, and was applied to determine compounds with acidic and basic properties from environmental samples, such as river water and effluent wastewater samples, with excellent selectivity and matrix effect values below -30% and apparent recovery results ranging from 52% to 105% for most of the compounds. The analytical method was validated for environmental water samples and used in the analysis of samples in which some of the target compounds were found at ng L−1 concentration levels

Exposure to nitrosamines in thirdhand tobacco smoke increases cancer risk in non-smokers

In addition to passive inhalation, non-smokers, and especially children, are exposed to residual tobacco smoke gases and particles that are deposited to surfaces and dust, known as thirdhand smoke (THS). However, until now the potential cancer risks of this pathway of exposure have been highly uncertain and not considered in public health policy. In this study, we estimate for the first time the potential cancer risk by age group through non-dietary ingestion and dermal exposure to carcinogen N-nitrosamines and tobacco-specific nitrosamines (TSNAs) measured in house dust samples. Using a highly sensitive and selective analytical approach we have determined the presence of nicotine, eight N-nitrosamines and five tobacco-specific nitrosamines in forty-six settled dust samples from homes occupied by both smokers and non-smokers. Using observations of house dust composition, we have estimated the cancer risk by applying the most recent official toxicological information. Calculated cancer risks through exposure to the observed levels of TSNAs at an early life stage (1 to 6. years old) exceeded the upper-bound risk recommended by the USEPA in 77% of smokers' and 64% of non-smokers' homes. The maximum risk from exposure to all nitrosamines measured in a smoker occupied home was one excess cancer case per one thousand population exposed.The results presented here highlight the potentially severe long-term consequences of THS exposure, particularly to children, and give strong evidence of its potential health risk and, therefore, they should be considered when developing future environmental and health policies

Horizontal and Vertical Distributions of Transparent Exopolymer Particles (TEP) in the NW Mediterranean Sea Are Linked to Chlorophyll a and O2 Variability

12 pages, 6 figures, 3 tables, supplementary material http://journal.frontiersin.org/article/10.3389/fmicb.2016.02159/full#supplementary-materialTransparent Exopolymer Particles (TEP) are relevant in particle and carbon fluxes in the ocean, and have economic impact in the desalination industry affecting reverse osmosis membrane fouling. However, general models of their occurrence and dynamics are not yet possible because of the poorly known co-variations with other physical and biological variables. Here, we describe TEP distributions in the NW Mediterranean Sea during late spring 2012, along perpendicular and parallel transects to the Catalan coast. The stations in the parallel transect were sampled at the surface, while the stations in the perpendicular transect were sampled from the surface to the bathypelagic, including the bottom nepheloid layers. We also followed the short-term TEP dynamics along a 2-day cycle in offshore waters. TEP concentrations in the area ranged from 4.9 to 122.8 and averaged 31.4 ± 12.0 μg XG eq L−1. The distribution of TEP measured in transects parallel to the Catalan Coast correlated those of chlorophyll a (Chla) in May but not in June, when higher TEP-values with respect to Chla were observed. TEP horizontal variability in epipelagic waters from the coast to the open sea also correlated to that of Chla, O2 (that we interpret as a proxy of primary production) and bacterial production (BP). In contrast, the TEP vertical distributions in epipelagic waters were uncoupled from those of Chla, as TEP maxima were located above the deep chlorophyll maxima. The vertical distribution of TEP in the epipelagic zone was correlated with O2 and BP, suggesting combined phytoplankton (through primary production) and bacterial (through carbon reprocessing) TEP sources. However, no clear temporal patterns arose during the 2-day cycle. In meso- and bathypelagic waters, where phytoplanktonic sources are minor, TEP concentrations (10.1 ± 4.3 μg XG eq l−1) were half those in the epipelagic, but we observed relative TEP increments coinciding with the presence of nepheloid layers. These TEP increases were not paralleled by increases in particulate organic carbon, indicating that TEP are likely to act as aggregating agents of the mostly inorganic particles present in these bottom nepheloid layersThis work was funded by projects funded by the Spanish Ministry of Science STORM (CTM2009-09352/MAR), SUMMER (CTM2008-03309/MAR), DOREMI (CTM2012-34294), REMEI (CTM2015-70340-R), ANIMA (CTM2015-65720-R), PEGASO (CTM2012-37615), and Grup consolidat de Recerca de la Generalitat de Catalunya (2014SGR/1179)Peer Reviewe

Avaliação de risco por exposição a hidrocarbonetos aromáticos policíclicos na saúde da população residente ao redor do complexo químico de Tarragona

One of the most important chemical industrial sites of Spain and, indeed, of southern Europe is close to the city of Tarragona and its surrounding villages. Therefore, the aim of this study was to calculate the chronic risk by inhalation of 18 atmospheric Polycyclic Aromatic Hydrocarbons (PAHs) for the population living in municipalities close to this chemical site. The sampling campaign was conducted between June 2008 and June 2009, and around 50 air samples were collected during different meteorological periods, in each of the three sampling sites selected for this study. Samples were taken for 24 h with the simultaneous collection of the particle phase (total suspended particles) on quartz microfiber filters, and the gas phase on polyu- rethane foam cartridges. The PAHs were extracted by pressurized liquid extraction and determined by gas chromatography-mass spectrometry.For calculating inhalation risk assessment, the 18 PAHs were expressed as benzo(a)pyrene equivalents using toxic equivalency factors. Risk was then calculated taking into account the World Health Organization (WHO) unit risk of 8.7 lung cancer cases per 100,000 people, with an exposure of 1 ng m-3 of benzo(a)pyrene over a lifetime of 70 years. The average lifetime lung cancer risk of the global study was 1.2·10-4. This risk is higher than the values recommended by the WHO and the US Environmental Protection Agency (USEPA), but it is lower than the threshold of 10-3, which is considered to be a definite risk.La ciudad de Tarragona y sus alrededores conviven con la actividad industrial de uno de los complejos más importantes de España y del sur de Europa. El objetivo de este estudio ha sido evaluar el riesgo crónico por inhalación de 18 hidrocarburos aromáticos policíclicos (HAP) en la población residente en los municipios ubicados alrededor de este complejo.Para el estudio se eligieron tres municipios y en cada uno de ellos se recogieron alrededor de 50 muestras desde junio de 2008 a junio de 2009. En cada muestra se captó, simultáneamente y durante 24 horas, la fase particulada (partículas totales en suspensión, PST) en filtro de fibra de cuarzo y la fase gaseosa en cilindros de espuma de poliuretano. Los HAP se extrajeron con diclorometano mediante extracción presurizada y se cuantificaron utilizando cromatografía de gases-espectrometría de masas.Para estimar el riesgo por inhalación a los HAP, primero se expresaron los 18 HAP como equivalentes de benzo(a)pireno utilizando factores de toxicidad equivalente, y posteriormente se aplicó el factor de riesgo, definido por la Organización Mundial de la Salud (OMS), de desarrollar cáncer de pulmón a lo largo de toda la vida, de 8,7 x 10-5 por ng m-3 de benzo(a)pireno.El valor medio de riesgo obtenido en el estudio ha sido de 1,2·10-4. Este valor supera los criterios recomendados por la OMS o la Agencia de Protección Medioambiental Americana (USEPA); sin embargo, es inferior a 10-3, umbral considerado como riesgo definitivo para la población.A cidade de Tarragona e os seus arredores convivem com a actividade industrial de um dos complexos mais importantes de Espan- ha e do sul da Europa. O objectivo desde estudo tem sido avaliar o risco crónico por inalação de 18 hidrocarbonetos aromáticos policíclicos (HAP) na população residente nos municípios localizados em redor deste complexo. Para este estudo foram escolhidos três municípios e em cada um deles recolheu-se à volta de 50 amostras desde Junho de 2008 a Julho de 2009. Em cada amostra captou-se, simultaneamente e durante 24 horas, a fase particulada (partículas totais em suspen- são, PST) em filtro de fibra de quartzo e a fase gasosa em cilindros de espuma de poliuretano. Os HAP extraíram-se com diclorometano através de extracção pressurizada e quantificação por cromatografia gasosa e espectrometria de massas. Para estimar o risco por inalação de HAP, primeiro expressaram-se os 18 HAP como equivalentes de benzo(a)pireno utilizando factores de toxicidade de equivalência, e posteriormente aplicou-se o factor de risco, definido pela Organização Mundial de Saúde (OMS), no desenvolvimento de cancro do pulmão para uma esperança de vida de 70 anos, de 8,7 x 10-5 por ng m-3 de benzo(a) pireno. O valor médio de risco obtido no estudo foi de 1,2·10-4. Este valor supera os critérios recomendados pela OMS e pela Agência de Protecção do Meio-ambiental Americana (USEPA); contudo, é inferior a 10-3, limite a partir do qual o risco é assumido para a população

Microporous polymer microspheres with amphoteric character for the solid-phase extraction of acidic and basic analytes

Solid-phase extraction (SPE) is a widely-used and very well-established sample preparation technique for liquid samples. An area of on-going focus for innovation in this field concerns the development of new and improved SPE sorbents that can enhance the sensitivity and/or the selectivity of SPE processes. In this context, mixed-mode ion-exchange sorbents have been developed and commercialised, thereby allowing enhanced capacity and selectivity to be offered by one single material. The ion-selectivity of these materials is such that either anion-exchange or cation-exchange is possible, however one limitation to their use is that more than one sorbent type is required to capture both anions and cations. In this paper, we disclose the design, synthesis and exploitation of a novel SPE sorbent based on microporous polymer microspheres with amphoteric character. We show that it is possible to switch the ion-exchange retention mechanism of the sorbent simply by changing the pH of the loading solution; anion-exchange dominates at low pH, cation-exchange dominates at high pH, and both mechanisms can contribute to retention when the polymer-bound amphoteric species, which are based on the α–amino acid sarcosine (N-methylglycine), are in a zwitterionic state. This is an interesting and useful feature, since it allows distinctly different groups of analytes (acids and bases) to be fractionated using one single amphoteric sorbent with dual-functionality. The sarcosine-based sorbent was applied to the SPE of acidic, basic and amphoteric analytes from ultrapure water, river water and effluent wastewater samples. Under optimised conditions (loading 100 mL of sample at pH 6, washing with 1 mL of MeOH and eluting with an acidic or basic additive in MeOH) the recoveries for most of the compounds were from 57% to 87% for river water and from 61% to 88% for effluent wastewater. We anticipate that these results will lay the basis for the development of a new family of multifunctional sorbents, where two or more separation mechanisms can be embedded within one single, bespoke material optimised for application to challenging chemical separations to give significant selectivity advantages over essentially all other state-of-the-art SPE sorbents

Surface ablation of RbTiOPO4 by femtosecond laser

We report here the results obtained in surface ablation of RbTiOPO4 single crystals by femtosecond laser. We fabricated and characterized one-dimensional (1D) diffraction gratings with different lattice spacings of 15 and 20 μm, and with a sub-modulation of the period introduced in the later. The optical and electronic microscopy characterization and filling factor analysis of these diffraction gratings are reported. We also show that the roughness generated on the grooves by the ablation process can be improved by chemical etching.This work was partially funded by the European Commission under the Seventh Framework Program under Project Cleanspace FP7-SPACE-2010-1-GA-263044, supported by the Spanish Government under Projects PI09/90527, TEC2009-09551, AECID A/024560/09, FIS2009-09522, HOPE CSD2007-00007 and SAUUL CSD2007-00013 (Consolider-Ingenio 2010), by Catalan Government under Projects 2009SGR235 and 2009SGR549, by Junta de Castilla y León under Project GR27, and by the Research Center on Engineering of Materials and Systems (EMaS) of the URV. J.J.C. is supported by the Education and Science Ministry of Spain and European Social Fund under the Ramón y Cajal program, RYC2006-858. We also acknowledge support from the Centro de Laseres Pulsados, CLPU, Salamanca, Spain