RETENTION BEHAVIOR OF HOMOLOGOUS SERIES IN REVERSED-PHASE LIQUID-CHROMATOGRAPHY USING MICELLAR, HYDROORGANIC, AND HYBRID MOBILE PHASES
RETENTION BEHAVIOR OF HOMOLOGOUS SERIES IN REVERSED-PHASE LIQUID-CHROMATOGRAPHY USING MICELLAR, HYDROORGANIC, AND HYBRID MOBILE PHASES
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DOI：
10.1021/ac00150a003
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发表时间：
1987-12-01
影响因子：
7.4
通讯作者：
NGEHNGWAINBI, J
中科院分区：
文献类型：
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作者：
KHALEDI, MG;PEULER, E;NGEHNGWAINBI, J
研究了烷基苯和正烷基酚在水有机相、胶束相和“杂化”流动相(水有机溶剂中的胶束)中的保留行为。对于常规的水-有机流动相，对数k‘与碳数之间存在线性关系。对于胶束和混合流动相(一个例外)，是容量因子k‘而不是logk’，它与碳数(Nc)线性相关。对于这些系统，对数k‘与Nc的曲线图具有明显的曲率，二次方程提供了最好的相关性。这种曲率反映了亚甲基选择性随Ne的变化，这是因为同一系列的不同化合物可以在胶束中占据不同的位置(具有不同的微环境极性)。在混合流动相中，有机溶剂在富水流动相中的对数k‘与体积分数呈良好的线性关系，溶剂强值的变化(对数k’vs的斜率)最小，而异丙醇的溶剂强度S的大小远小于水-丙醇二元溶剂。行为上的差异归因于胶束中溶质局部化的重要性，可能还有有机溶剂的局部化。通常情况下，同系物在杂化流动相中的保留特性与纯水胶束流动相相似。在过去的7年中，使用浓度高于临界胶束浓度(CMC)的表面活性剂溶液作为反相液相色谱(RPLC)流动相已受到广泛关注(1-18)。胶束是表面活性剂单体的动态聚集体，在RPLC的水相流动相中提供了与中性和带电溶质相互作用的疏水和静电场所，可以取代有机改性剂。表面活性剂的类型和浓度(CMC以上)用于控制流动相的选择性和强度。在胶束LC中的保留行为是基于三相模型并通过关联保留与胶束浓度的方程(2-4)得到的。自从Armstrong和Henry(1)的第一份报告以来，胶束LC的大部分工作都集中在探索这种技术的独特性能，特别是这种技术相对于传统的水有机RPLC的优势。在过去的几年里，胶束诱导荧光增强和胶束稳定的室温磷光检测高效液相色谱的优点已经被许多工作者报道，包括同时分离离子和中性化合物的能力、快速的梯度能力、与电化学检测的梯度兼容性、直接进样蛋白质基生物样品、低毒性、低成本等。胶束流动相提供了独特的优势，这是无法提供的
The retention behavior of-alkylbenzenes and n-alkyl-phenones was studied In hydro-organic, micellar, and" hybrid"(micelles In hydro-organic solvents) mobilephases. For conventionalhydro-organic mobile phases a linear relationship exists between log k'and the number of carbons. For micellar and hybrid mobile phases (with one exception), It Is the capacity factor, k'and not log k', which Is linearly dependent on the carbon number (Nc). For these systems, the plot of log k'vs Nc has a clear curvature and a quadratic equation provides the best correlation. This curvature, which reflects the variation of methylene selectivity with Ne, Is due to the fact that different compounds of a homologous series can occupy various locations (with different microenvironment polarities) In micelles. With the hybrid mobile phases ex-cellent linearity Is observed for log k'vs volume fraction of organic solvent In a water-rich mobile phase, the variation of the solvent strength values (slope of log k'vs) is minimized, and the magnitude of the solvent strength, S, for 2-propanol is much smaller thanthat observed with the binary water-propanol solvents. The differences In behavior are attributed to the significance of the localization of solutes and perhaps the organic solvent In the micelles. In general, the retention characteristics of the homologous series In hybrid mobile phases are similar to those with purely aqueous micellar mobile phases.The use of surfactant solutions, at concentrations above critical micelle concentration (cmc), as mobile phases for re-versed-phase liquid chromatography (RPLC) has received much attention in the past 7 years (1-18). Micelles, which are dynamic aggregates of surfactant monomers, provide hydrophobic and electrostatic sites of interaction with neutral and charged solutes in the aqueous mobile phase of RPLC and can be used in place of organic modifiers. The type and concentration (above cmc) of surfactant are used to control the selectivity and the strength of the mobile phase. The retention behavior in micellar LC has been formulated based on a three-“phase” model and through equations correlating retention to micelle concentration (2-4). Since the first report by Armstrong and Henry (1), most of the workin micellar LC has been focused on exploring the unique capabilities and especially the advantages of this technique over the traditional hydro-organic RPLC. In the past few years the advantages of micellar inducedfluorescence enhancement and micellestabilized room temperature phosphorescence detection for HPLC, capability of simultaneous separation of ionicand neutral compounds, rapid gradient capability, gradient com-patibility with electrochemical detection, direct injection of protein based biological samples, low toxicity, low cost, etc., have been reportedby many workers (1-18). Micellar mobile phases provide distinct advantages, which can not be offered