期刊
JOURNAL OF CHROMATOGRAPHY A
卷 1229, 期 -, 页码 38-47出版社
ELSEVIER
DOI: 10.1016/j.chroma.2012.01.029
关键词
Aqueous two-phase partitioning; Solvatochromic; Salt additives
资金
- national research grant [PTDC/EQU-EQU/112812/2009]
- Fundacao para a Ciencia e a Tecnologia (FCT) [PTDC/EQU-EQU/112812/2009, SFRH/BPD/45055/2008]
- Fundação para a Ciência e a Tecnologia [PTDC/EQU-EQU/112812/2009] Funding Source: FCT
The solvatochromic parameters characterizing the solvent dipolarity/polarizability (pi*), solvent hydrogen-bond donor acidity (alpha), and solvent hydrogen-bond acceptor basicity (beta) of aqueous media were measured in the coexisting phases of aqueous Dextran-Ficoll, Dextran-Ucon, Dextran-PEG, PEG-Ucon, Ficoll-Ucon, and Ficoll-PEG two-phase systems (ATPS). Ionic composition of each ATPS included 0.15 M KCl, 0.15 M KBr, 0.15 M NaBr, 0.1 M Na2SO4, and 0.1 M Li2SO4 in 0.01 M sodium phosphate buffer (NaPB), pH 7.4; and 0.01 M and 0.11 M sodium phosphate buffer, pH 7.4. Partition ratios of sodium salts of dinitrophenylated (DNP) amino acids with aliphatic side-chains (glycine, alanine, norvaline, norleucine, and alpha-amino-n-caprylic acid) were measured in all ATPSs, and the results were evaluated in terms of the differences between the relative hydrophobicity (parameter E) and the electrostatic properties (parameter C) of the aqueous media of the coexisting phases. It was established that parameter E is described by a linear combination of the differences between the solvent dipolarity/polarizability (Delta pi*) and between the solvent hydrogen-bond acidity (Delta alpha)of the media in the coexisting phases. Parameter C depends on the phase forming polymer pair and is shown to be described by a linear combination of three parameters: the differences between the solvent hydrogen-bond acidity (Delta alpha) and between the solvent hydrogen-bond basicity (Delta beta) of the media in the coexisting phases, and a measure of the effect of a given salt additive on the hydrogen bonds in water. This effect was represented by a parameter (Kb-l), characterizing the equilibrium between populations of hydrogen bonds with a bent hydrogen bond conformation and with linear hydrogen bond conformation affected by a given salt additive. (C) 2012 Elsevier B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据