Wipf Peter, Werner Stefan, Twining Leslie A, Kendall Christopher
Center for Chemical Methodologies and Library Development (UPCMLD), University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA.
Chirality. 2007 Jan;19(1):5-9. doi: 10.1002/chir.20331.
Evaporative light-scattering detection (ELSD) is widely applied in the HPLC analysis of organic compounds lacking a UV chromophore. However, this detection method is generally unsuitable for determination of enantiomeric ratios (er). The er calculated from a UV trace and an ELS trace of the same compound differs significantly. Because of the nonlinear concentration response of the ELS detector, a compound with an er of 95:5 appears to be enantiomerically pure by ELS detection. It is possible to obtain a calibration curve and to calculate a correction factor, but this procedure is time consuming and therefore not very practical for routine analyses. In contrast, a charged aerosol detector allows a very accurate determination of the enantiomeric ratios. Like the ELS detection, the CA detection is independent of the chromophore properties of the substrate. Therefore, we recommend the use of CA instead of ELS detection for determination of the enantiomeric ratios of non-UV active compounds.
蒸发光散射检测（ELSD）广泛应用于缺乏紫外发色团的有机化合物的高效液相色谱分析。然而，这种检测方法通常不适用于对映体比例（er）的测定。由同一化合物的紫外色谱图和蒸发光散射色谱图计算得到的对映体比例差异显著。由于蒸发光散射检测器的浓度响应呈非线性，一个对映体比例为95:5的化合物在蒸发光散射检测中看似对映体纯。虽然可以获得校准曲线并计算校正因子，但该过程耗时，因此对于常规分析不太实用。相比之下，带电气溶胶检测器能够非常准确地测定对映体比例。与蒸发光散射检测一样，带电气溶胶检测与底物的发色团性质无关。因此，我们建议使用带电气溶胶检测而非蒸发光散射检测来测定非紫外活性化合物的对映体比例。
