The technique of laser-induced atomic-ionization (AI) in flames has been used for direct determination of Na, K, Rb, and Cs in samples such as water, high-purity alkali metals and their salts and polymeric organosilicon compounds. Different procedures for sample introduction into the flame were studied: (a) the sample was placed onto the cathode of the detector (this gave limits of detection for Na and Cs of 4 x 10(-16) and 2 x 10(-15) g, respectively), (b) electrothermal vaporization and (c) aspiration of the sample into the flame. To reduce the interference of SiO(2) in the AI determination of K in polymeric organosilicon compounds (at the level of 10(-3)-10(-5)%), a procedure involved additional electrical heating of the FID cathode was developed. The efficiency of certain schemes for the laser stepwise and two-photon excitation of atoms was compared for determination of Na.
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http://dx.doi.org/10.1016/0039-9140(87)80025-5 | DOI Listing |
F1000Res
January 2025
Departments of Psychiatry, Neurology, Radiology, and Neuroscience, Washington University in St. Louis School of Medicine, St. Louis, MO, 63110, USA.
Reddy and Reddy (2014) discuss the optimal timing for lithium levels in patients taking once-daily extended-release lithium formulations. They argue for blood sampling 24 h after the previous dose rather than the standard 12 h. I interpret the data quite differently.
View Article and Find Full Text PDFSci Rep
January 2025
Faculty of Computer and Information, South Valley University, Qena, 83523, Egypt.
Ra, Th, and K levels in various foods frequently consumed by Egyptians were determined using a gamma-ray spectrometer based on the germanium detector (HPGe). Activity concentrations of Ra, Th, and K were in the range of < 0.10 to 0.
View Article and Find Full Text PDFPLoS One
January 2025
The Key Laboratory of Cyber-Physical Power System of Yunnan Universities, Yunnan Minzu University, Kunming, Yunnan Province, China.
Current researches on sodium penetration in electrolytic aluminum cathode carbon blocks primarily measure cathode expansion curves, showing mostly macroscopic characteristics. However, the microscopic structure is often underexplored. As a porous medium, the diffusion performance of cathode carbon blocks is closely tied to their internal pore structure.
View Article and Find Full Text PDFBMC Cardiovasc Disord
January 2025
Department of Internal Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
Background: Hypertension in young adults is often due to secondary causes, and investigating these can be resource-intensive. This study aimed to identify clinical and biochemical markers that could suggest secondary hypertension in individuals under 40 years.
Materials And Methods: A 6-year retrospective observational cohort study included 207 young adults with hypertension who were assessed for secondary causes such as hyperthyroidism, primary aldosteronism, Cushing's syndrome, pheochromocytoma, and renovascular disease.
Materials (Basel)
January 2025
School of Metallurgical Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
To investigate the influence of alkali metal compounds in different forms on the sintering mineralization process of iron ore, the basic sintering characteristics of iron ore with alkali metal contents ranging from 0 to 4% were measured using the micro-sintering method, and the influence mechanism was analyzed using thermodynamic analysis and first-principles calculations. The results showed that (1) the addition of KCl/NaCl increased the lowest assimilation temperature (LAT) and the index of liquid-phase fluidity (ILF), while that of KCO/NaCO decreased the LAT but increased the ILF of iron ore. (2) The pores formed by the volatilization of KCl/NaCl suppressed the diffusion of Fe and Ca, which inhibited the formation of silico-ferrite of calcium and aluminum (SFCA).
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