A comparison of microsecond vs. millisecond dwell times on particle number concentration measurements by single particle ICPMS

With the growing popularity of nanomaterials in a wide variety of products and processes, the need to measure and characterize these materials has also grown. For metallic or metal-containing engineered nanoparticles (NPs), single particle ICP-MS (SP-ICP-MS) has been developed and is growing in popularity due to its ability to rapidly detect and characterize a large number of particles, determine particle size and size distributions, the particle number concentration in a sample, and the elemental mass concentration of both dissolved and particulate species. SP-ICP-MS has been applied to a wide variety of sample types1-5, demonstrating its versatility. A key variable in SP-ICP-MS, which must be applied correctly for accurate measurement of particle concentration, is the dwell time of the ICP-MS. Although this topic has been discussed previously6,7, this work will focus on direct comparisons of results using both microsecond and millisecond dwell times. Since a detailed version of this work is available8, only a brief description will be given here

Assessment of metals bound to marine plankton proteins and to dissolved proteins in seawater

Studies based on laser ablation–inductively coupled plasma-mass spectrometry (LA–ICP-MS) have been performed to assess metal bound to dissolved proteins and proteins from marine plankton after two-dimensional polyacrylamide gel electrophoresis (2D PAGE). Dissolved proteins were pre-concentrated from surface seawater (60 L) by tangential ultrafiltration with 10 kDa molecular weight cut-off (MWCO) membranes and further centrifugal ultrafiltration (10 kDa) before proteins isolation by methanol/chloroform/water precipitation. Proteins isolation from plankton was assessed after different trichloroacetic acid (TCA)/acetone and methanol washing stages, and further proteins extraction with a phenol solution. LA–ICP-MS analysis of the electrophoretic profiles obtained for dissolved proteins shows the presence of Cd, Cr, Cu, and Zn in five spots analyzed. These proteins exhibit quite similar molecular weights (within the 10–14 kDa range) and pIs (from 5.8 to 7.3). Cd, Cr, Cu, and Zn have also been found to be associated to proteins isolated from plankton samples. In this case, Cd has been found to be bound to proteins of quite different molecular weight (9, 13 and 22 kDa) and pIs (4.5, 5.2, 5.5, and 10). However, trace elements such as Cr, Cu and Zn appear to be mainly bound to plankton proteins of low molecular weight and variable pI

Acute aquatic toxicity to zebrafish and bioaccumulation in marine mussels of antimony tin oxide nanoparticles

Antimony tin oxide (Sb2O5/SnO2) is effective in the absorption of infrared radiation for applications, such as skylights. As a nanoparticle (NP), it can be incorporated into films or sheets providing infrared radiation attenuation while allowing for a transparent final product. The acute toxicity exerted by commercial Sb2O5/SnO2 (ATO) NPs was studied in adults and embryos of zebrafish (Danio rerio). Our results suggest that these NPs do not induce an acute toxicity in zebrafish, either adults or embryos. However, some sub-lethal parameters were altered: heart rate and spontaneous movements. Finally, the possible bioaccumulation of these NPs in the aquacultured marine mussel Mytilus sp. was studied. A quantitative analysis was performed using single particle inductively coupled plasma mass spectrometry (sp-ICP-MS). The results indicated that, despite being scarce (2.31 × 106 ± 9.05 × 105 NPs/g), there is some accumulation of the ATO NPs in the mussel. In conclusion, commercial ATO NPs seem to be quite innocuous to aquatic organisms; however, the fact that some of the developmental parameters in zebrafish embryos are altered should be considered for further investigation. More in-depth analysis of these NPs transformations in the digestive tract of humans is needed to assess whether their accumulation in mussels presents an actual risk to humans.Fundação para a Ciência e Tecnologia | Ref. 2020.04021.CEECIN

Actas de las V Jornadas ScienCity 2022. Fomento de la Cultura Científica, Tecnológica y de Innovación en Ciudades Inteligentes

ScienCity es una actividad que viene siendo continuada desde 2018 con el objetivo de dar a conocer los conocimientos y tecnologías emergentes siendo investigados en las universidades, informar de experiencias, servicios e iniciativas puestas ya en marcha por instituciones y empresas, llegar hasta decisores políticos que podrían crear sinergias, incentivar la creación de ideas y posibilidades de desarrollo conjuntas, implicar y provocar la participación ciudadana, así como gestar una red internacional multidisciplinar de investigadores que garantice la continuación de futuras ediciones. En 2022 se recibieron un total de 48 trabajos repartidos en 25 ponencias y 24 pósteres pertenecientes a 98 autores de 14 instituciones distintas de España, Portugal, Polonia y Países Bajos.Fundación Española para la Ciencia y la Tecnología-Ministerio de Ciencia, Innovación y Universidades; Consejería de la Presidencia, Administración Pública e Interior de la Junta de Andalucía; Estrategia de Política de Investigación y Transferencia de la Universidad de Huelva; Cátedra de Innovación Social de Aguas de Huelva; Cátedra de la Provincia; Grupo de investigación TEP-192 de Control y Robótica; Centro de Investigación en Tecnología, Energía y Sostenibilidad (CITES

Des dimensions significatives de l'espace historique

Dans l'historiographie récente on a donné une grande importance à l'ensemble des problèmes liés à l'espace. Cet article a pour but d'analyser les différents sens qu'acquiert ce terme dans les textes historiographiques. Il existe différents emplois selon que l'on considère l'espace comme principe de l'entendement, de la raison ou de l'imagination historiques, en faisant la différence entre des emplois qui se superposent et provoquent de nombreuses confusions historiographiques.En la historíografia reciente se ha venido dando una gran importancia al conjunto de los problemas relacionados con el espacio. El objeto del présente trabajo consiste en analizar los diferentes significados que dicho término puede adquirir en los textos historiográficos. Se establecen diferentes usos según se considère al espacio como principio del entendimiento, la razón o la imaginación históricas, diferenciando una série de usos que normalmente se superponen y dan lugar a numerosas confusiones historiográficas.Bermejo Barrera José Carlos, Bouyssou M.-P. Des dimensions significatives de l'espace historique. In: Dialogues d'histoire ancienne, vol. 18, n°2, 1992. pp. 29-49

Inductively coupled plasma-optical emission spectrometry/mass spectrometry for the determination of Cu, Ni, Pb and Zn in seawater after ionic imprinted polymer based solid phase extraction

The capabilities of a synthesized ionic imprinted polymer (IIP), originally prepared for Ni recognition/pre-concentration from seawater, have been evaluated for other trace elements pre-concentration. The polymer has been synthesized by the precipitation polymerization technique using a ternary pre-polymerization complex formed by the template (Ni), the monomer (2-(diethylamino) ethyl methacrylate, DEM) and a non-vinylated chelating agent (8-hydroxyquinoline, 8-HQ). Since the complexing agent (8-HQ) is trapped into the polymeric matrix, but is not linked to the polymer chains, specific interactions between the functional groups (present in the monomer and the complexing agent) and other trace elements rather than Ni may occur. Results have shown that the IIP offers imprinting properties for the template (Ni(II)) and also for Cu(II), Pb(II), Zn(II), As(V) and Cd(II), with analytical recoveries close to 100% for all elements except for As(V) and Cd(II) (around 70%), whereas the non-imprinted polymer (NIP) did not show affinity for any trace element. In addition, the polymer does not interact with alkaline or alkaline-earth metals, so Na, K, Mg and Ca from the seawater salt matrix could be effectively removed. Variables affecting the IIP-solid phase extraction (SPE) process (pH, load flow rate and concentration and volume of the eluting solution) were completely studied. Inductively coupled plasma-optical emission spectrometry (ICP-OES) and inductively coupled plasma-mass spectrometry (ICP-MS) have been used as multi-element detectors. Acidified seawater samples must only be treated to fix an alkaline pH (8.5 ± 0.5) and passed through IIP-SPE cartridges. After seawater sample loading (250 mL), analytes were eluted with 2.5 mL of 2.0 M nitric acid, offering a pre-concentration factor of 100. Therefore, the limits of detection (LODs) of the method were 0.14, 0.15, 0.18 and 0.03 μg L-1, for Ni, Cu, Pb and Zn, respectively, when using ICP-OES detection and 0.0022, 0.0065, 0.0040 and 0.009 μg L-1, for Ni, Cu, Pb and Zn, respectively, for ICP-MS detection. Accuracy of the method was assessed by analyzing SLEW-3 (estuarine water), and TM-23.3 and TM-24 (lake water) certified reference materials. © 2009 Elsevier B.V. All rights reserved