Catching particles by atomic spectrometry: Benefits and limitations of single particle - inductively coupled plasma mass spectrometry

Single particle inductively coupled plasma mass spectrometry (SP-ICP-MS) has led ICP-MS into a new dimension, turning an ensemble technique for elemental and isotope ratio analysis into a particle counting technique and well beyond. SP-ICP-MS allows the detection of particles, their size characterization and the quantification of their number and mass concentrations, as well as the dissolved forms of the target element(s). Although the technique is mostly applied to metal- and metalloid-based nanoparticles, its application to microparticles and carbon-based particles are emerging. After twenty years since the first publications and more than ten years of ongoing development, SP-ICP-MS has reached a high degree of maturity, with an increasing number of applications in a wide range of fields. Despite this trend, there are aspects related to the fundamentals of the technique that still require further studies. This review is organized around the fundamentals of the technique along with the different steps and processes involved, from the sample introduction to the signal processing, offering an updated view of these topics, focusing on the benefits and current limitations of the technique, as well as its future perspectives

An approach to the natural and engineered nanoparticles analysis in the environment by inductively coupled plasma mass spectrometry

Different approaches to the most relevant and recent studies and applications of inductively coupled plasma mass spectrometry (ICP-MS) applied to the analysis of natural and engineered nanoparticles in the environment are described. Usually several separation methods like polyacrylamide gel electrophoresis (PAGE), field-flow fractionation (FFF) and size exclusion chromatography (SEC) are used prior to the mass spectrometric measurements. In many cases the use of these hyphenated techniques provides important methodologies to know the bioavailability, mobility and toxicity of elements in life and environmental sciences. Alternatively, the capabilities of the single particle detection by ICP-MS (SD-ICP-MS) for the selective identification, characterization and determination of engineered nanoparticles will be also discussed

Chunta secreta o arenga crítica y divertida, que fan sis personets de distinguit caracter en la ciutad de Valensia [Texto impreso] : Queixansa ágriament de la mala estació del temps, pues no se atreveixen á eixir á collir lo que átres han sembrat, perque no els délmen, y fasen pagar el clam

Hay un ejemplar encuadernado con: Romans, y coloqui nou, pera divertir el humor y desterrar la melancolia, yà que no tenim dinès ... (NP849.91/3085).Hay un ejemplar encuadernado con : Poesías colocadas en el pórtico del Convento de San Francisco de Valencia (NP849.91/3086)Serrano Morales data el impreso entre 1822 y 182

Bifurcation Diversity in an Annular Pool Heated from Below: Prandtl and Biot Numbers Effects

In this article the instabilities appearing in a liquid layer are studied numerically by means of the linear stability method. The fluid is confined in an annular pool and is heated from below with a linear decreasing temperature profile from the inner to the outer wall. The top surface is open to the atmosphere and both lateral walls are adiabatic. Using the Rayleigh number as the only control parameter, many kind of bifurcations appear at moderately low Prandtl numbers and depending on the Biot number. Several regions on the Prandtl-Biot plane are identified, their boundaries being formed from competing solutions at codimension-two bifurcation points.The code developed for this article was finished during a visit of S. Hoyas to the Lehrstuhl fur Stromungsmechanik of the University of Erlangen-Nurnberg, funded by the Government of Valencia and the Universitat Politecnica de Valencia. S. Hoyas would like to thank to Prof. Delgado and Dr. Ausmeier for their support and kindness. Last, but not least, S. Hoyas is and always will be, in debt with his PhD advisors, Prof. Herrero, Prof. Mancho and Prof. Pardo.Torregrosa, AJ.; Hoyas, S.; Pérez Quiles, MJ.; Mompó Laborda, JM. (2013). Bifurcation Diversity in an Annular Pool Heated from Below: Prandtl and Biot Numbers Effects. Communications in Computational Physics. 13(2):428-441. doi:10.4208/cicp.090611.170212aS428441132Shi, W., Ermakov, M. K., Li, Y.-R., Peng, L., & Imaishi, N. (2009). Influence of Buoyancy Force on Thermocapillary Convection Instability in the Differentially Heated Annular Pools of Silicon Melt. Microgravity Science and Technology, 21(S1), 289-297. doi:10.1007/s12217-009-9118-8SCHWABE, D., ZEBIB, A., & SIM, B.-C. (2003). Oscillatory thermocapillary convection in open cylindrical annuli. Part 1. Experiments under microgravity. Journal of Fluid Mechanics, 491, 239-258. doi:10.1017/s002211200300541xPelacho, M. A., & Burguete, J. (1999). Temperature oscillations of hydrothermal waves in thermocapillary-buoyancy convection. Physical Review E, 59(1), 835-840. doi:10.1103/physreve.59.835Mercier, J. F., & Normand, C. (1996). Buoyant‐thermocapillary instabilities of differentially heated liquid layers. Physics of Fluids, 8(6), 1433-1445. doi:10.1063/1.868920Herrero, H., & Mancho, A. M. (1998). Influence of aspect ratio in convection due to nonuniform heating. Physical Review E, 57(6), 7336-7339. doi:10.1103/physreve.57.7336Shi, W., Liu, X., Li, G., Li, Y.-R., Peng, L., Ermakov, M. K., & Imaishi, N. (2010). Thermocapillary Convection Instability in Shallow Annular Pools by Linear Stability Analysis. Journal of Superconductivity and Novel Magnetism, 23(6), 1185-1188. doi:10.1007/s10948-010-0661-8Daviaud, F., & Vince, J. M. (1993). Traveling waves in a fluid layer subjected to a horizontal temperature gradient. Physical Review E, 48(6), 4432-4436. doi:10.1103/physreve.48.4432Canuto, C., Hussaini, M. Y., Quarteroni, A., & Zang, T. A. (1988). Spectral Methods in Fluid Dynamics. doi:10.1007/978-3-642-84108-8Burguete, J., Mukolobwiez, N., Daviaud, F., Garnier, N., & Chiffaudel, A. (2001). Buoyant-thermocapillary instabilities in extended liquid layers subjected to a horizontal temperature gradient. Physics of Fluids, 13(10), 2773-2787. doi:10.1063/1.1398536Mancho, A. M., & Herrero, H. (2000). Instabilities in a laterally heated liquid layer. Physics of Fluids, 12(5), 1044-1051. doi:10.1063/1.870359Smith, M. K., & Davis, S. H. (1983). Instabilities of dynamic thermocapillary liquid layers. Part 1. Convective instabilities. Journal of Fluid Mechanics, 132, 119-144. doi:10.1017/s0022112083001512Hoyas, S., Mancho, A. M., Herrero, H., Garnier, N., & Chiffaudel, A. (2005). Bénard–Marangoni convection in a differentially heated cylindrical cavity. Physics of Fluids, 17(5), 054104. doi:10.1063/1.1876892Peng, L., Li, Y.-R., Shi, W.-Y., & Imaishi, N. (2007). Three-dimensional thermocapillary–buoyancy flow of silicone oil in a differentially heated annular pool. International Journal of Heat and Mass Transfer, 50(5-6), 872-880. doi:10.1016/j.ijheatmasstransfer.2006.08.015Herrero, H., Hoyas, S., Donoso, A., Mancho, A. M., Chacón, J. M., Portugués, R. F., & Yeste, B. (2003). Journal of Scientific Computing, 18(3), 315-328. doi:10.1023/a:1022678124929Hoyas, S., Herrero, H., & Mancho, A. M. (2002). Thermal convection in a cylindrical annulus heated laterally. Journal of Physics A: Mathematical and General, 35(18), 4067-4083. doi:10.1088/0305-4470/35/18/306Hoyas, S., Herrero, H., & Mancho, A. M. (2002). Bifurcation diversity of dynamic thermocapillary liquid layers. Physical Review E, 66(5). doi:10.1103/physreve.66.057301Ganier N. , PhD thesis, http://nicolasgarnier.free.fr/these-garnier.pdf, 2002.RILEY, R. J., & NEITZEL, G. P. (1998). Instability of thermocapillary–buoyancy convection in shallow layers. Part 1. Characterization of steady and oscillatory instabilities. Journal of Fluid Mechanics, 359, 143-164. doi:10.1017/s0022112097008343Mancho, A., Herrero, H., & Burguete, J. (1997). Primary instabilities in convective cells due to nonuniform heating. Physical Review E, 56(3), 2916-2923. doi:10.1103/physreve.56.2916Ezersky, A. B., Garcimartín, A., Burguete, J., Mancini, H. L., & Pérez-García, C. (1993). Hydrothermal waves in Marangoni convection in a cylindrical container. Physical Review E, 47(2), 1126-1131. doi:10.1103/physreve.47.1126Pardo, R., Herrero, H., & Hoyas, S. (2011). Theoretical study of a Bénard–Marangoni problem. Journal of Mathematical Analysis and Applications, 376(1), 231-246. doi:10.1016/j.jmaa.2010.10.06

Long-term study of antibiotic presence in Ebro river basin (Spain): identification of the emission sources

Water monitoring is key to determining the presence of potentially hazardous substances related to urban activities and intensive farming. This research aimed to perform a long-term (four years) quantitative monitoring of selected antibiotics (azithromycin, enrofloxacin, trimethoprim and sulfadiazine) both in rivers and wastewaters belonging to the Ebro River basin (North of Spain). The target antibiotics were chosen on the basis of a preliminary multispecies screening. The analysis of the antibiotics was carried out by LC-MS/MS on wastewater-treatment plant (WWTP) effluent, effluents of a slaughterhouse and hospital, rivers downstream and upstream of these WWTPs, and rivers close to extensive farming areas. The ANOVA test was performed to study the significant differences between the points exposed to concrete emission sources and antibiotic concentration. The monitoring, carried out from 2018 to 2020, has been essential to illustrating the presence of the most abundant antibiotics that were detected in the Ebro River basin. Enrofloxacin has appeared in river waters in significant concentrations, especially near intensive farming, meanwhile azithromycin has been frequently detected in wastewaters. Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland

Comparative study of extraction methods of silver species from faeces of animals fed with silver-based nanomaterials

Extractions methods based on ultrapure water, tetramethylammonium hydroxide (TMAH), and tetrasodium pyrophosphate (TSPP) were applied to faeces collected from two in vivo experiments of pigs and chickens fed with a silver-based nanomaterial to study the fate and speciation of silver. For TMAH extraction, cysteine and CaCl2 were used to evaluate their stabilization effect on the silver forms. The analytical techniques single-particle inductively coupled plasma mass spectrometry (SP-ICP-MS), hydrodynamic chromatography hyphenated to ICP-MS (HDC-ICP-MS) and asymmetric flow field flow fractionation coupled to ICP-MS (AF4-ICP-MS) were applied to the simultaneous detection of particulate and dissolved silver. Results have shown that water extraction was a suitable option to assess the environmental release of silver, with percentages of 3 and 9% for faeces of pigs and chickens, respectively. The use of TMAH extraction combined with SP-ICP-MS analysis was useful to characterize Ag-containing particles (less than 1%). Both stabilizers, cysteine and CaCl2, have a similar effect on silver nanoparticle preservation for chicken faeces, whereas cysteine-Triton was better for pig samples. In any case, silver extraction efficiency with TMAH was low (39–42%) for both types of faeces due to a matrix effect. TSPP followed by ICP-MS enabled the fractionation of the silver in the faeces, with silver sulphide (41%) and ionic silver (62%) being the most abundant fractions

Capeamento, incisão na base do ramo e uso do ácido indolbutírico na propagação vegetativa do guaranazeiro (Paullinia cupana Var. Sorbilis (Mart.) Ducke).

O guaraná se destaca como um dos produtos de alto potencial econômico e de grande significado social no meio rural amazônico. O guaranazeiro pode ser propagado por sementes e por estacas. A propagação por sementes tem o inconveniente de obter uma grande variabilidade de plantas no campo. A utilização da propagação vegetativa,propiciando a manutenção das características da planta-matriz, possibilita a produção de exemplares padronizados de alta qualidade. Este trabalho teve como objetivo avaliar o potencial de propagação vegetativa do guaranazeiro (Paullinia cupana var. sorbilis(Mart.)Ducke) por meio das técnicas de capeamento e anelamento, além da aplicação do hormônio indutor de crescimento sobre o enraizamento de estacas. Os cultivares selecionados foram BRS CG882 e CMU 381 que apresentam alta produtividade e baixo nível de enraizamento. O delineamento experimental foi inteiramente ao acaso, em arranjo fatorial 2 x 2 x 2, correspondendo às duas técnicas aplicadas nos ramos, 2 cultivares de guaraná, e a aplicação ou ausência do hormônio, com 3 repetições e 10 estacas por unidade experimental. Após 60 dias da instalação dos tratamentos nas plantas matrizes os ramos foram cortados para a confecção das estacas no viveiro, onde permaneceram por 90 dias sob nebulização intermitente e 50% de irradiância. A aplicação de AIB (2.000 mg.kg-1)aumentou o número de estacas enraizadas. O percentual de estacas mortas não diferiu entre os três tratamentos na ausência de AIB, no entanto, quando se aplicou o hormônio houve redução desse percentual tanto para estacas de ramos capeados quanto para as de ramos anelados. O tratamento com capeamento dos ramos e aplicação de AIB foi o que apresentou maiores valores médios de número de raízes (21,81); comprimento das raízes(6,86 cm) e peso da matéria seca das raízes (4,20 g planta-1)

How to trust size distributions obtained by single particle inductively coupled plasma mass spectrometry analysis

Single particle inductively coupled plasma mass spectrometry (SP-ICP-MS) is a technique widely used to obtain direct information about the number concentration and the size distribution of nanoparticles in liquid suspensions. However, its methods still lack clear quality control strategies to confirm the validity of the information derived from them. Only the detection of the complete size distribution of the nanoparticles in a sample over the size critical value ensures obtaining unbiased quantitative information, otherwise information should be restricted to report the presence of nanoparticles over a certain size and number concentration since their actual total number concentration is underestimated and the size overestimated. Under the latter conditions, data processing produces histograms showing the tails of the incomplete size distributions, although apparently, complete distributions can also be obtained when particle events are recorded as peaks, as reported here for the first time. The occurrence of these misleading situations must be critically evaluated for each SP-ICP-MS analysis. An approach, based on estimation of size critical values and successive dilutions, is proposed for the assessment of the validity of the quantitative information obtained, together with specific criteria for reconsidering the information that can be derived from those measurements. The approach was verified with different case studies and applied to the analysis of complex nanomaterials, confirming the validity of the reported information by comparison with other techniques. A calculation tool is also included to facilitate the estimation of size critical values under experimental conditions

A New m-Learning Scenario for a Listening Comprehension Assessment Test in Second Language Acquisition [SLA]

Computer adaptive language testing offers the possibility to research and practice m-learning using ubiquitous technology. Virtual education in m-learning uses conventional Learning Objects (LO) to enable the possibility of development of several tasks oriented towards language learning including the assessment and verification of skill improvements in second language acquisition. So far, there are few research papers on the impact of using new multimodal digital resources as LO in the design process of foreign language assessment tests through mobile devices because many English certification tests still continue to use traditional testing techniques [face-to-face and pen-and-paper assessments] combined with conventional digital environments oriented to virtual education. Learning languages requires not only new m-learning scenarios for assessment but also multimodal interactive environments to improve the user's experience during proficiency tests or language certification. Multimodal object learning such as augmented environments, learning games, spatial sound, etc. can be integrated into an assessment process to enhance the user´s experience by simulating natural communicative scenarios. The present article defines an innovative new m-learning scenario for listening comprehension assessment in an on-line test by implementing a multimodal audio learning source named binaural sound. Use of this technology will enable demonstration of other possibilities of human interaction to improve the user's experience in language learning through sound perception and its cognition from the user in an especific learning task

Detection, characterization and quantification of inorganic engineered nanomaterials: A review of techniques and methodological approaches for the analysis of complex samples

The increasing demand of analytical information related to inorganic engineered nanomaterials requires the adaptation of existing techniques and methods, or the development of new ones. The challenge for the analytical sciences has been to consider the nanoparticles as a new sort of analytes, involving both chemical (composition, mass and number concentration) and physical information (e.g. size, shape, aggregation). Moreover, information about the species derived from the nanoparticles themselves and their transformations must also be supplied. Whereas techniques commonly used for nanoparticle characterization, such as light scattering techniques, show serious limitations when applied to complex samples, other well-established techniques, like electron microscopy and atomic spectrometry, can provide useful information in most cases. Furthermore, separation techniques, including flow field flow fractionation, capillary electrophoresis and hydrodynamic chromatography, are moving to the nano domain, mostly hyphenated to inductively coupled plasma mass spectrometry as element specific detector. Emerging techniques based on the detection of single nanoparticles by using ICP-MS, but also coulometry, are in their way to gain a position. Chemical sensors selective to nanoparticles are in their early stages, but they are very promising considering their portability and simplicity. Although the field is in continuous evolution, at this moment it is moving from proofs-of-concept in simple matrices to methods dealing with matrices of higher complexity and relevant analyte concentrations. To achieve this goal, sample preparation methods are essential to manage such complex situations. Apart from size fractionation methods, matrix digestion, extraction and concentration methods capable of preserving the nature of the nanoparticles are being developed. This review presents and discusses the state-of-the-art analytical techniques and sample preparation methods suitable for dealing with complex samples. Single- and multi-method approaches applied to solve the nanometrological challenges posed by a variety of stakeholders are also presented