Linear solvation energy relationships in micellar liquid chromatography and micellar electrokinetic capillary chromatography.
Linear solvation energy relationships in micellar liquid chromatography and micellar electrokinetic capillary chromatography.
复制标题
胶束液相色谱和胶束电动毛细管色谱中的线性溶剂化能关系。
DOI：
10.1016/0021-9673(94)01003-w
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Khaledi,MG
中科院分区：
文献类型：
--
作者：
Yang,S;Khaledi,MG
采用线性溶剂化能关系（LSERs）来评价和表征影响胶束液相色谱（MLC）和胶束电动毛细管色谱（MEKC）中保留行为的化学相互作用。在两种阴离子表面活性剂十二烷基硫酸钠（SDS）和胆酸钠（SC）以及一种阳离子表面活性剂十四烷基三甲基溴化铵（C14TAB）的作用下，发现MLC和MEKC中溶质容量因子、胶束结合常数及其溶剂变色参数之间存在高度相关性。令人惊讶的是，在C14TAB MLC体系中，容量因子（k′）与溶剂化变色参数的相关性优于log k′与溶剂化变色参数的相关性，这与SDS MLC体系中观察到的行为相反。采用LSERs对C14TAB MLC体系的容量因子进行了表征。研究发现，少量短链醇（例如，7%的2-丙醇或5%的丁醇）的加入不会显著改变k′与溶剂变色参数之间的高度相关性。通过比较流动相和固定相的化学性质差异，解释了各系数随有机溶剂体积分数的变化。用二苯色谱柱和c8色谱柱进行LSER研究，发现固定相对MLC中化学相互作用有显著影响。LSERs还用于表征MEKC中的保留行为。对25种具有SDS和SC胶束的非带电取代芳香族化合物和多环芳香烃的溶质容量因子的对数与其溶剂致变色参数之间存在高度相关。发现溶质的大小和碱度是影响MEKC中溶质迁移行为的两个主要因素。
Linear solvation energy relationships (LSERs) were used to evaluate and characterize chemical interactions that influence retention behavior in micellar liquid chromatography (MLC) and micellar electrokinetic capillary chromatography (MEKC). High correlations were found between solutes' capacity factors in MLC and in MEKC, as well as binding constants to micelles and their solvatochromic parameters using two anionic surfactants, sodium dodecyl sulfate (SDS) and sodium cholate (SC), and one cationic surfactant, tetradecyltrimethylammonium bromide (C14TAB). Surprisingly, in the C14TAB MLC system capacity factor (k′) vs. solvatochromic parameters gives better correlation than log k′ vs. solvatochromic parameters, which is an opposite behavior to that observed in the SDS MLC system. The capacity factors in the C14TAB MLC system were characterized using LSERs with and without organic modifiers. It was found that the addition of a small amount of short-chain alcohols (e.g., 7% 2-propanol or 5% butanol) does not significantly change the high correlations between k′ vs. solvatochromic parameters. The changes in the coefficients with the volume fraction of organic solvents were explained by comparing the differences in chemical natures between mobile phase and stationary phase. Stationary phase shows a significant effect on the chemical interactions in MLC through LSER study using a diphenyl column and a C8column. LSERs were also used to characterize retention behavior in MEKC. High correlations between the logarithm of solutes' capacity factors and their solvatochromic parameters were observed for a group of 25 uncharged substituted aromatic compounds and polycyclic aromatic hydrocarbons with SDS and SC micelles. It was found that solutes' size and basicity are the two dominant factors that influence the migration behavior in MEKC.