The objective of this study was to establish the best parameters to correct for matrix effects in the chemical analysis of a siliceous geologic material rich in metallic elements of high economic value, such as La, Ce, Nd, Sm, and Gd (rare earth elements), using empirical influence coefficients applied to wavelength dispersive X-ray fluorescence (WDXRF). At present, this material is considered waste derived from the extraction of tin from cassiterite, a special ore from which niobium and tantalum are also processed. In this study, a reliable methodology for the analysis of rare earth elements in a siliceous matrix using the WDXRF technique was developed. This procedure may be useful in promoting industrial processes for chemical control in solid matrices, as the usual techniques are only possible in liquid media and require acid dissolution.
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http://dx.doi.org/10.1016/j.talanta.2019.120254 | DOI Listing |
Chemistry
January 2025
The University of Arizona, Chemistry and BioChemistry, 1306 E University Blvd, CSML 638, 85719, Tucson, UNITED STATES OF AMERICA.
Fluorination of tris(2,6-dimethoxyphenyl)-methylium ((DMP)3C+) was achieved through the partial defluorination of the methyl 2,3,5,6-tetrafluorobenzoate via nucleophilic aromatic substitution. Using the fluorinated 2F((DMP)3C+) as a precursor, fluorinated tetramethoxy- and dimethoxyquin- acridinium salts (2F4 and 2F5 respectively) and trioxo-, azadioxo-, and diazaoxo- triangulenium salts (2F6, 2F7 and 2F8 respectively) were synthesized successfully in good to moderate yields. Fluorination induced significant red shifts in absorption (16 to 29 nm) and emission (13 to 41 nm) maxima, and increased electrophilicity as evidenced by lower reduction potentials.
View Article and Find Full Text PDFJ Biomed Opt
January 2025
Lund University, Department of Physics, Lund, Sweden.
Significance: The spatial distribution of the photosensitizing drug concentration is an important parameter for predicting the photodynamic therapy (PDT) outcome. Current diffuse fluorescence tomography methods lack accuracy in quantifying drug concentration. The development of accurate methods for monitoring the temporal evolution of the drug distribution in tissue can advance the real-time light dosimetry in PDT of tumors, leading to better treatment outcomes.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Chemical Engineering, University of Technology, Baghdad, Iraq.
Palygorskite exhibits distinctive morphological and textural characteristics due to its fibrous and micropore nature. This research experimentally investigates the microstructure of palygorskite and how acid treatment changes the fibrous shape and ability to adsorb. Acetic and hydrochloric acid were used to study the effect of acid on palygorskite fibrous morphology.
View Article and Find Full Text PDFNo Shinkei Geka
January 2025
Department of Neurosurgery, Osaka Medical and Pharmaceutical University.
Surgery for spinal intramedullary tumors remains a major challenge for neurosurgeons. Successful surgery requires experience, skill, and intraoperative imaging support. Fluorescence imaging technology has become a valuable support in neurosurgical procedures of not only the brain but also the spinal cord.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Institute of Chemicobiology and Functional Materials, School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, 200 Xiao Ling Wei, Nanjing 210094, China. Electronic address:
Bacterial cellulose (BC) is a porous biopolymer synthesized via microbial fermentation. BC exhibits remarkable properties and is widely utilized in diverse applications. Despite all its merits, BC is constrained by certain performance limitations.
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