We present the application of nanosecond laser ablation (LA) coupled to a 'Nu Plasma HR' multi collector inductively coupled plasma mass spectrometer (MC-ICP-MS) for the direct analysis of U isotope ratios in single, 10-20 μm-sized, U-doped glass particles. Method development included studies with respect to (1) external correction of the measured U isotope ratios in glass particles, (2) the applied laser ablation carrier gas (i.e. Ar versus He) and (3) the accurate determination of lower abundant (236)U/(238)U isotope ratios (i.e. 10(-5)). In addition, a data processing procedure was developed for evaluation of transient signals, which is of potential use for routine application of the developed method. We demonstrate that the developed method is reliable and well suited for determining U isotope ratios of individual particles. Analyses of twenty-eight S1 glass particles, measured under optimized conditions, yielded average biases of less than 0.6% from the certified values for (234)U/(238)U and (235)U/(238)U ratios. Experimental results obtained for (236)U/(238)U isotope ratios deviated by less than -2.5% from the certified values. Expanded relative total combined standard uncertainties U(c) (k = 2) of 2.6%, 1.4% and 5.8% were calculated for (234)U/(238)U, (235)U/(238)U and (236)U/(238)U, respectively.
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http://dx.doi.org/10.1016/j.jenvrad.2012.03.017 | DOI Listing |
Mar Pollut Bull
December 2024
Centre for Marine Living Resources and Ecology (CMLRE), Kochi, Kerala, India; Central University of Kerala (CUK), Kasargod, Kerala, India.
This study investigated major contributors of the particulate organic matter (POM) using stable isotope ratios of particulate organic carbon (δC) and its relationship with phytoplankton composition during three seasons across six coast-offshore transects in the eastern Arabian Sea (EAS). Results revealed significant spatiotemporal variations, with elevated δC in coastal waters during the winter and summer monsoon (-22.40 ± 1.
View Article and Find Full Text PDFProbl Radiac Med Radiobiol
December 2024
National University of Physical Education and Sport of Ukraine, 1 Fizkultury Str., Kyiv, 03150, Ukraine.
Objective: to assess the impact of stressful life events occuring with the period of restrictive measures introductionconnected to the COVID-19 pandemic and during the full-scale Russian aggression, on the anthropometric indicators and body composition of children aged 10-17 years.
Materials And Methods: The research group consisted of 56 boys and 70 girls aged 10-17 years who lived in radioactively contaminated areas of Zhytomyr, Rivne, and Kyiv regions with a soil contamination density of 137Cs from 18 kBq/m2 to 235 kBq/m2. The impact of stressful factors was assessed using the stress perception scale (PSS-10).
Anal Chem
December 2024
State Key Laboratory of Continental Dynamics, Department of Geology, Northwest University, Xi'an 710069, China.
Matrix effects can significantly bias Hf isotopic ratios in situ Hf isotope analyses using laser ablation (LA-) multicollector inductively coupled plasma mass spectrometry (MC-ICP-MS), necessitating the use of matrix-matched reference materials for accurate microanalysis. This work introduces a novel fast hot-pressing (FHP) sintering method to produce such reference materials efficiently for in situ analysis. By optimizing sintering temperatures, FHP technology enables the rapid preparation of in situ analysis reference materials with dense structures and homogeneous Hf isotopic compositions.
View Article and Find Full Text PDFSci Total Environ
December 2024
Faculty of Mathematics and Physics, Charles University, Sokolovska 49, 186 75 Prague, Czech Republic.
In many countries worldwide, NO emissions currently decrease as a result of pollution control, while NH emissions stagnate or continue to increase. Little is known about horizontal deposition of NO and NH, the oxidation/neutralization products of these primary pollutants. To close the knowledge gap, we studied atmospheric inputs of NO and NH at two mountain-top sites near the Czech-German-Polish borders during winter.
View Article and Find Full Text PDFSci Total Environ
December 2024
Laboratoire G-Time, Department of Geosciences, Environment and Society, Université Libre de Bruxelles, ULB, CP 160/02, Avenue F.D. Roosevelt, 50, B-1050 Brussels, Belgium.
Effective methods for measuring sudden environmental changes are crucial for understanding how cities respond to shifts in human activity. This study examines atmospheric metal outputs during the COVID-19 restrictions using honey samples collected from three land use types in Brussels Capital Region (BCR), Belgium, and Metro Vancouver Regional District (MVRD), Canada to study changes as the result of restrictions. By comparing these cities with distinct sizes, ages, and structures, we assess how urban environments responded to pandemic-induced restrictions.
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