Insights into chiral recognition mechanisms in supercritical fluid chromatography V. Effect of the nature and proportion of alcohol mobile phase modifier with amylose and cellulose tris-(3,5-dimethylphenylcarbamate) stationary phases
Insights into chiral recognition mechanisms in supercritical fluid chromatography V. Effect of the nature and proportion of alcohol mobile phase modifier with amylose and cellulose tris-(3,5-dimethylphenylcarbamate) stationary phases
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DOI：
10.1016/j.chroma.2014.11.033
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发表时间：
2014-12-19
影响因子：
4.1
通讯作者：
West, Caroline
中科院分区：
文献类型：
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作者：
Khater, Syame;West, Caroline
在手性固定相（CSP）的对映选择性超临界流体色谱（SFC）中，二氧化碳的洗脱强度通常通过使用极性有机溶剂（也称为改性剂）来调节。醇类如甲醇、乙醇和异丙醇是最常用的助溶剂。虽然手性SFC的大多数应用都是通过改变助溶剂的性质和比例来优化的，但只有有限数量的深入研究来揭示助溶剂对对映体分离过程的影响。为了阐明流动相共溶剂对SFC对映选择性分离的影响，我们在淀粉质（Chiralpak AD-H）和纤维素质（Lux cellulose-1） CSP上分析了各种化合物（手性和非手性）。由于必须考虑到改性剂极性和位阻的影响，因此对几种不同的酒精溶剂进行了评估：甲醇、乙醇、1-丙醇、2-丙醇和1-丁醇，它们在二氧化碳中的比例为10%。对一组选定的外消旋物进行进一步分析，每种醇的比例从5%到25%不等。此外，由于溶剂混合物有时会产生意想不到的结果，因此也对50:50的甲醇和乙醇混合物进行了评估。化学计量学方法提供了对映体分离过程的一些见解，并有助于识别流动相条件之间的差异。(C) 2014 Elsevier B.V.版权所有
In enantioselective supercritical fluid chromatography (SFC) with chiral stationary phases (CSP), the elution strength of carbon dioxide is usually modulated by the use of polar organic solvents, also called modifiers. Alcohols like methanol, ethanol and isopropanol are the most commonly used co-solvents. While most applications of chiral SFC are optimized through a process of varying the co-solvent nature and proportion, only a limited number of thorough investigations have been carried out to unravel the effects of the co-solvent on the enantioseparation process.In an attempt to clarify the effect of the mobile phase co-solvent on enantioselective SFC separations, a wide range of compounds (achiral and chiral) were analyzed on an amylosic (Chiralpak AD-H) and a cellulosic (Lux cellulose-1) CSP. The influence of the modifier polarity and steric hindrance must be considered thus several different alcoholic solvents were evaluated: methanol, ethanol, 1-propanol, 2-propanol and 1-butanol, with a proportion of 10% in carbon dioxide. A selected group of racemates was further analyzed with varying proportions of each alcohol ranging from 5 to 25%. Besides, because mixtures of solvents were sometimes reported to produce unexpected results, a 50:50 mixture of methanol and ethanol was also evaluated. Chemometric methods provide some insight into the enantio-separation process and help identifying the differences between the mobile phase conditions. (C) 2014 Elsevier B.V. All rights reserved.