Reversed-phase liquid chromatography (RPLC) represents an effective separation method, and is widely employed as the second dimension in most 2D-LC systems. Nevertheless, the solvent effect of the eluent from the first dimension on RPLC presents a challenge to the online coupling of RPLC with other separation modes, particularly normal phase liquid chromatography (NPLC). To address this issue, a comprehensive understanding of the solvent effect is essential. Following a comprehensive investigation into the influence of diverse solvents on RPLC separations, it was observed that alkane solvents, such as n-hexane, exhibited a pronounced tendency to be retained during RPLC separations. Such solvents do not affect the analysis of samples with weaker retention abilities than themselves, even when a large injection volume is used. The solvent effect was thus reduced by employing n-hexane-based solvent dilution. Leveraging the markedly enhanced solvent tolerance and extensive injection volume in RPLC, a versatile integration of the NPLC and RPLC was devised, necessitating merely a purge pump and a 10 port 2 position valve in conjunction with two sample loops. The novel 2D-LC system was then deployed for the analysis of propolis, a naturally occurring complex sample, and demonstrated remarkable separation efficiency.
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http://dx.doi.org/10.1016/j.chroma.2024.465278 | DOI Listing |
Fish Physiol Biochem
January 2025
Department of Biological Sciences, College of Science, University of Jeddah, P.O. Box 80327, Jeddah 21589, Saudi Arabia.
High cadmium (Cd) concentrations pose a threat to aquatic life globally. This study examined the efficiency of adding purslane (Portulaca oleracea L.) leaf powder (PLP) to Oreochromis niloticus diets on Cd's negative effects.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Key Laboratory for Advanced Materials, Feringa Nobel Prize Scientist Joint Research Center, Frontiers Science Center for Materiobiology and Dynamic Chemistry, Institute of Fine Chemicals, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, P. R. China.
Understanding and effectively controlling molecular conformational changes are essential for developing responsive and dynamic molecular systems. Here, we report that an oriented external electric field (OEEF) is an effective catalyst for the cis-trans isomerization of stiff-stilbene, a key component of overcrowded alkene-based rotary motors. This reversible isomerization occurs under ambient conditions, is free from side reactions, and has been verified using ultraperformance liquid chromatography and UV-vis absorption spectroscopy.
View Article and Find Full Text PDFBiomed Chromatogr
February 2025
Guangdong Provincial key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou, China.
Praziquantel (PZQ) is the most effective treatment for schistosomiasis, commonly administered as a racemic mixture of the two enantiomers. Despite many reports on the pharmacokinetics of PZQ, the stereoselective pharmacokinetics of PZQ and its major metabolite 4-hydroxypraziquantel (4-OH-PZQ) remain poorly understood in goats. In this study, the chiral LC-MS/MS method was further optimized for separating and quantifying PZQ, trans-4-OH-PZQ, and cis-4-OH-PZQ and their enantiomers and then applied for the molecular pharmacokinetics of three analytes in black goat plasma.
View Article and Find Full Text PDFNutrients
January 2025
School of Pharmacy, Federal University of Bahia, Barão de Jeremoabo Street, Salvador 40170-115, Brazil.
Studies have demonstrated that resveratrol exerts several pharmacological effects. However, the pharmacokinetic parameters are not completely established. This study describes the plasma pharmacokinetics and tissue distribution of resveratrol after administration by different routes and doses in rats.
View Article and Find Full Text PDFNutrients
December 2024
Department of Dietetics and Bromatology, Wroclaw Medical University, Borowska 211, 50-556 Wrocław, Poland.
To assess the associations between serum and dietary polyunsaturated fatty acids (PUFAs), as well as the inflammatory potential of diet measured by the Children's Dietary Inflammatory Index (C-DII), and recurrent respiratory infections (RRIs) in children. We enrolled 44 children aged 3-16 years with RRIs and 44 healthy controls. Dietary intake was assessed using a 7-day food record from which PUFA intake and C-DII were calculated.
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