18α(H)-、18β(H)-齐墩烷和羽扇烷的全二维气相色谱分离。

Separation of 18α(H)-, 18β(H)-oleanane and lupane by comprehensive two-dimensional gas chromatography.

机构信息

Curtin University, WA Organic and Isotope Geochemistry Centre, Department of Chemistry, GPO Box U1987, Perth, WA 6845, Australia.

出版信息

J Chromatogr A. 2011 Aug 12;1218(32):5549-53. doi: 10.1016/j.chroma.2011.06.021. Epub 2011 Jun 17.

DOI:10.1016/j.chroma.2011.06.021

PMID:21737090

Abstract

18α(H)-, 18β(H)-oleanane and lupane are angiosperm-derived biomarkers that are used as age indicators for the Late Cretaceous onwards when the first proliferation of angiosperms occurred. In addition, the 18α(H)-/18β(H)-oleanane ratio is employed as a thermal maturity parameter of crude oil. However, evidence has shown that accurate quantification of these compounds has been impeded by inadequate chromatographic separation by traditional one-dimensional gas chromatography. In this study, we present the separation of 18α(H)-, 18β(H)-oleanane and lupane with comprehensive two-dimensional gas chromatography (GC×GC). Furthermore, it was observed that 18β(H)-oleanane elutes earlier than 18α(H)-oleanane in second dimension (polarity) which we attribute to steric hindrance effects. Two GC conditions have been developed in order to achieve baseline separation of the triterpenoids of interest in complex mixtures such as sediment extracts and crude oils.

摘要

18α(H)-、18β(H)-齐墩烷和羽扇烷是被子植物衍生的生物标志物，可用于指示晚白垩世以来的时代，此时被子植物首次大量繁殖。此外，18α(H)-/18β(H)-齐墩烷比值可用作原油热成熟度参数。然而，有证据表明，传统一维气相色谱法的色谱分离不充分，阻碍了这些化合物的准确定量。在本研究中，我们采用全二维气相色谱（GC×GC）对 18α(H)-、18β(H)-齐墩烷和羽扇烷进行了分离。此外，我们观察到 18β(H)-齐墩烷在第二维（极性）中的洗脱时间早于 18α(H)-齐墩烷，这归因于空间位阻效应。为了实现沉积物提取物和原油等复杂混合物中感兴趣的三萜类化合物的基线分离，已经开发了两种 GC 条件。