Micellar electrokinetic chromatography (MEKC) systems with mixed pseudostationary phases of the bile surfactants sodium cholate (SC) and sodium deoxycholate (SDC) have been characterized by means of the solvation parameter model. The importance of characterizing systems with an appropriate set of solutes that embrace a wide range of descriptor values has been proven as they can significantly influence the value of the system constants. The fit of the solvation parameter model to the experimental log k data has been compared for each SC-SDC system when the Abraham descriptors and the Poole optimized descriptors, recently proposed, are used. In both cases, the variation in MEKC surfactant composition results in similar changes in the coefficients of the correlation equations, which in turn leads to similar information on solute-solvent and solute-micelle interactions. It is demonstrated that SDC is more hydrogen-bond acidic and hydrophobic but slightly less polarizable than SC. Systems with intermediate selectivity are obtained through mixtures of both surfactants.
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http://dx.doi.org/10.1016/j.chroma.2010.01.001 | DOI Listing |
Heliyon
January 2025
Laboratory of Vaccine and Biomolecules, Institute of Bioscience, Universiti Putra Malaysia, 43400, UPM Serdang, Selangor, Malaysia.
Pyrethroid pesticides are essential for modern agriculture, helping to control pests and protect crops. However, due to growing concerns about their potential impact on human health and the environment, reliable detection methods are essential to ensure food safety. In this literature review, we explore the techniques used over the past decade to detect pyrethroid residues in agricultural products.
View Article and Find Full Text PDFMolecules
January 2025
Institute of Environmental Engineering, Polish Academy of Sciences, M. Skłodowskiej-Curie 34, 41-819 Zabrze, Poland.
The cosmetics industry is one of the fastest-growing sectors worldwide. The dynamic evolution of this industry results in an increasingly diverse range of products containing various active ingredients. Ensuring the quality of these products is crucial for consumer safety, necessitating the use of advanced analytical methods and adherence to legal regulations.
View Article and Find Full Text PDFAnal Chim Acta
January 2025
School of Pharmacy, Jiangsu University, Zhenjiang, 212013, PR China. Electronic address:
Background: Capillary electrophoresis (CE) is a highly versatile separation technique widely used in analytical chemistry. Traditionally, CE can be categorized as either aqueous or non-aqueous systems based on the buffer solvents employed. For decades, non-aqueous CE has been predominantly associated with the use of organic solvents, a perception deeply ingrained in the scientific community.
View Article and Find Full Text PDFJ Chromatogr A
January 2025
State Key Laboratory of Component-based Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China; Tianjin Key Laboratory of Phytochemistry and Pharmaceutical Analysis, Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China. Electronic address:
A rapid and sensitive enrichment technique, field enhanced sample injection-dynamic pH junction-sweeping (FESI-DypH-sweeping) was successfully developed for the simultaneous separation and concentration of alkaloids and stereoisomers of Uncariae ramulus cum uncis (UR) by cyclodextrin electrokinetic chromatography (CDEKC) with diode array detection system. The sample was prepared in a low-conductivity (FESI), low-pH (DypH) sample matrix (4 mM phosphate buffer, 3% methanol, pH=3), and the background electrolyte (BGE) consisted of a high-conductivity, high-pH buffer (40 mM phosphate buffer, pH 7.0, 8 mg/mL carboxymethyl-β-cyclodextrin, and 30% methanol).
View Article and Find Full Text PDFJ Inorg Biochem
February 2025
Department of Chemistry and Biochemistry, Brigham Young University, Benson Building, Campus Drive, Provo, UT 84604, USA. Electronic address:
Human serum transferrin can bind up to two iron atoms, one in each of its two domains which are known as the N-lobe and the C-lobe. Ferric pyrophosphate and ferric citrate have been shown to direct loading into the C-lobe and N-lobe, respectively. We report that the iron supplement ferric pyrophosphate citrate directs iron to the C-lobe.
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