To understand the change in environmental conditions when a probe is incorporated in micelles, an absorption and fluorescence spectral study on the solubilization behaviour of 5-methoxy tryptamine (5-MT) and N,N-dimethyl-5-methoxy tryptamine (5-NMT) has been made in CTAB and SDS for their neutral and cationic forms. The blue shift in emission wavelength is accompanied by increase in intensity with increasing surfactant concentration for almost all the cases except for the cationic probe in CTAB surfactant. This exceptional behaviour can be attributed to the quenching of emission intensity caused by Br(-) ions. Spectral correlations with solvent polarity parameters indicate relatively less polar binding sites in CTAB and SDS as compared to water. The binding constant and cmc values have been determined for CTAB and SDS using both the neutral and the cationic probes, which are in good agreement with the literature values. Higher value of binding constant and lower polarity of the binding sites justify 5-NMT as a better binding probe as the two methyl groups make the molecule more hydrophobic and drag it to the interior of both the micelles.
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http://dx.doi.org/10.1016/j.saa.2007.05.035 | DOI Listing |
Molecules
November 2024
Department of Analytical Chemistry, Institute of Chemical Sciences, Faculty of Chemistry, Maria Curie-Sklodowska University, 20-031 Lublin, Poland.
This paper proposes a simple, environmentally friendly, and efficient procedure for preparing natural water samples for the voltammetric determination of trace amounts of Se(IV). The method is based on premixing a sample with Amberlite XAD-7 resin at 50 °C. The composition of the 10 mL solution consists of the sample to be analysed, 0.
View Article and Find Full Text PDFACS Omega
December 2024
School of Chemistry and Chemical Engineering, Shandong University, Jinan 250000, PR China.
The application of an electric field to demulsification of oil-in-water (O/W) emulsions has received extensive attention. However, microcosmic information about the effect of surfactant type on the demulsification of an O/W emulsion under an electric field is still rare. In this work, the effects of cationic surfactant cetyltrimethylammonium bromide (CTAB) and anionic surfactant sodium dodecyl sulfate (SDS) on oil droplet demulsification in an emulsion under a pulsed-DC electric field were studied by molecular dynamics (MD) simulation.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
December 2024
Laboratório de Catálise e Fenômenos Interfaciais, Chemistry Department, Federal University of Santa Catarina, 88040-900 Florianópolis, SC, Brazil. Electronic address:
Coumarins are a class of compounds known for their synthetic and structural versatility, as well as their properties of great interest, such as biological and photophysical activities, and their application in the analysis of molecular microenvironments and their characteristics, such as pH. In this work, the synthesis of 7-hydroxy-6-methoxy-2-oxo-2H-chromene-3-carboxylic acid (3-SCA) was reported, and its absorption, emission and excitation spectral properties, along with photophysical properties such as molar absorption coefficient, lifetime, and Stokes Shift (Δν) in different solvents and pHs, were evaluated for the first time. High values of fluorescence quantum yield were observed for 3-SCA in solvents of different polarities, with a lifetime of approximately 5 ns.
View Article and Find Full Text PDFMar Biotechnol (NY)
November 2024
Institute of Fisheries Science, National Taiwan University, Taipei, 10617, Taiwan.
Octocorals, vital components of reef ecosystems, inhabit various marine environments across diverse climate zones, spanning from tropical shallows to frigid deep-sea regions. Certain octocoral species, notably Lobophytum and Sinularia, are particularly intriguing due to their production of diverse metabolites, warranting continuous investigation. Although octocorals played the roles in coral ecosystems, the studies are rare in comparison to scleractinian corals, especially in transcriptomic and genomic data.
View Article and Find Full Text PDFNanotechnology
November 2024
Department of Rheumatology and Immunology, Guangdong Second Provincial General Hospital, Guangzhou 510317, People's Republic of China.
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