Fast and precise access to enantiomerization rate constants in dynamic chromatography
Fast and precise access to enantiomerization rate constants in dynamic chromatography
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DOI：
10.1002/chir.20276
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发表时间：
2006-08-01
期刊：
影响因子：
2
通讯作者：
Trapp, O.
中科院分区：
文献类型：
--
作者：
Trapp, O.
本文给出了动态色谱中互变对映体洗脱曲线统一方程的解析解。速率常数k（1）和k（-1）以及吉布斯活化能直接从色谱参数（相互转化对映体的保留时间tRA和tRA、半峰宽w（A）和w（B）以及相对平台高度hp）以及对映体的初始量A（0）和B-0获得，而无需任何迭代和耗时的计算步骤。因此，该方程不再限于外消旋分析物。通过与125，000个对映异构体模拟洗脱曲线的数据集进行比较，验证了此处提供的分析解决方案。此外，还发现，与基于迭代计算机模拟的评估方法相比，使用统一方程从定义的数据集的回收率平均高出40%。将新方程应用于1-正丁基-2-叔丁基二氮杂环丁烷的对映体选择性气相色谱测定。活化参数（Δ H-双匕首= 112.6 +/-2.5kJ/mol和Δ S-双匕首= -27 +/-2J/（K mol））是从10 K步长中100 ℃和140 ℃之间的温度依赖性测量获得的。
An analytical solution of the unified equation to evaluate elution profiles of interconverting enantiomers in dynamic chromatography is presented. Rate constants k(1) and k(-1) and Gibbs activation energies are directly obtained from the chromatographic parameters (retention times tRA and tRA of the interconverting enantiomers, the peak widths at half height w(A) and w(B), and the relative plateau height hp), and the initial amounts A(0) and B-0 of the enantiomers without any iterative and time consuming computational step. Therefore, this equation is no longer limited to racemic analytes. The analytical solution presented here was validated by comparison with a dataset of 125,000 simulated elution profiles of enantiomerizations. Furthermore, it was found that the recovery rate from a defined dataset is on average 40% higher using the unified equation compared to evaluation methods based on iterative computer simulation. The new equation was applied to determine the enantiomerization rate constant of 1-n-butyl-2-tert-butyldiazitidine by enantioselective gas chromatography. The activation parameters (Delta H-double dagger = 112.6 +/- 2.5 kJ/mol and Delta S-double dagger = -27 +/- 2 J/(K mol) were obtained from temperature-dependent measurements between 100 degrees C and 140 degrees C in 10K steps.