Deviations from Beer's law in electronic absorption and circular dichroism: Detection for enantiomeric excess analysis
作者:Qiaozhi Tang、Lu Zhao、Jingqian Xie、Kai Liu、Weiping Liu、Shanshan Zhou
DOI:10.1002/chir.23072
日期:2019.7
signal ratio can be used for enantiomeric excess (ee) analysis within linear range. However, CD detection often requires a high sample concentration where deviations from Beer's law may occur. Individual enantiomers of four chiral compounds were separated from commercial racemates by semipreparative high‐performance liquid chromatography (HPLC) with chiral columns. They were used to trace possible deviations
电子吸收(UV)与圆二色性(CD)信号之比可用于线性范围内的对映体过量(ee)分析。但是,CD检测通常需要很高的样品浓度,这可能会偏离比尔定律。通过手性色谱柱的半制备型高效液相色谱(HPLC)从市售外消旋物中分离出四种手性化合物的单个对映体。它们用于在非手性HPLC上使用光电二极管阵列检测器和CD检测器来追踪UV和CD检测中的可能偏差。当进样量增加时,具有相同ee值的样品的CD / UV比降低多达7.8%至52%,这表明ee与CD / UV的线性标准曲线仅在狭窄范围内有效。为了将样本量扩展到更大的范围,基于两个二阶多项式函数开发了一种数据处理方法,这些函数被构造为适合两个对映体的UV和CD信号强度之间的关系。此外,建立了一种基于三阶多项式函数的简化方法来计算ee值。两种方法的预测ee值与实验ee值之间的差异均在±0.08以内。就我们所知,这是首次研究在进行ee分析的UV和CD检测中都考虑到