Small quantities (parts per 10-9) of testosterone were determined in the presence of large amounts of other steroids in urine samples obtained during pregnancy by subjecting their trimethylsilyl derivatives to spectrofluorimetry on alumina after purification by thin-layer chromatography on silica gel. The activity of the alumina and the fluorescence reactions are discussed.
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http://dx.doi.org/10.1016/s0021-9673(00)91217-2 | DOI Listing |
Spectrochim Acta A Mol Biomol Spectrosc
December 2024
Department of Chemistry, Faculty of Science, Gazi University, Yenimahalle, Ankara 06560, Turkey. Electronic address:
Coumarin compounds have heterocyclic core with different properties such as high quantum yields, broad Stokes shifts, and superior photophysical and biological activity. It is known that fluorescence properties increase with increased intramolecular charge transfer in systems where electron-withdrawing or donor groups are attached to different positions of the coumarin compound. When these compounds interact with analytes in the environment, the analytes in the environment can be detected by quenching or increasing fluorescence.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Chemistry, Amrita School of Physical Sciences Coimbatore, Amrita Vishwa Vidyapeetham, Coimbatore, India.
Carbon dots doped with metals and non-metals have gained much popularity due to the enhancement in their optical and electronic properties. In this study, polyethyleneimine-functionalized transition metal (nickel or copper) doped carbon dots (CD, NiCD and CuCD) were synthesized through hydrothermal method. The carbon dots exhibited a blue fluorescence at 470 nm when excited at 350 nm.
View Article and Find Full Text PDFCrit Rev Anal Chem
January 2025
Department of Electronics and Communication, Vidyavardhaka College of Engineering, Mysuru, India.
Water contaminated with chromium (Cr) poses significant risks to public health and the environment, necessitating reliable detection techniques. This review study uniquely provides a comprehensive analysis of optical methods for detecting Cr pollution in water, focusing on both reagent-based and reagentless approaches, as well as various sensing platforms. Unlike existing reviews that primarily focus on electrochemical and colorimetric/fluorimetric methods, this work highlights the untapped potential of optical technologies, such as colorimetry, SPR, UV-Vis spectroscopy, and more, in detecting distinct Cr species, including reagent and reagentless based approaches.
View Article and Find Full Text PDFAnal Chem
January 2025
Laboratorio de Investigación y Desarrollo en Métodos Analíticos (LIDMA), Facultad de Ciencias Exactas, Universidad Nacional de La Plata (UNLP), Calle 49 y 115 (B1900AJL), La Plata 1900, Argentina.
A new strategy is proposed for second-order data fusion based on the simultaneous modeling of two data sets using the multivariate curve resolution-alternating least-squares (MCR-ALS) model, applying a new constraint during the ALS stage, called "Proportionality of Scores". This approach allows for the fusion of data from different sources, without requiring common dimensionality, and enables the application of specific constraints to each data set. This strategy was applied to the determination of five pharmaceutical contaminants (naproxen, danofloxacin, ofloxacin, sarafloxacin, and enoxacin) in environmental water samples, by fusing two sets of excitation-emission fluorescence matrices, measured before and after photochemical derivatization.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
December 2024
Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, Kafrelsheikh University, Kafrelsheikh 33511, Egypt. Electronic address:
The current study introduces the first micellar-enhanced spectrofluorimetric approach for the estimation of the commonly abused CNS antitussive, dextromethorphan (DXM) in its syrup and biological fluids. A micellar solution of sodium dodecyl sulfate (SDS) containing DXM showed high native fluorescence emission at 305 nm following excitation at 224 nm. Using SDS as a micellar system resulted in about a 2.
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