The development of the analytical method for carbon isotopic analysis of isoprenoids

Xiaofang Huang, Han Zhang, Tengteng Wang, Tiantian Tang

Isoprenoid compounds (such as sterols and phytols) are important components of lipids, which are characterized by their species-specific origins. The isotopic values of isoprenoid compounds can be used to indicate the migration and burial of organic compounds from specific biological origins, providing critical evidence on the origin and evolution of marine ecosystems. This research aim to establish the method to analyze the isotopic ratios of sterols, phytols and other isoprenoids from natural environment samples. The method development includes optimizing the pre-treatment method and exploring the protocol for Gas Chromatography-Isotope Ratio Mass Spectrometer(GC-IRMS) technique. In this work, androsteranol standards and phytol standards with known isotope ratios were used as the internal and external standard. The pretreatment was optimized at the steps of saponification, Silica-gel separation and derivatization. The efficiency of pretreatment was tested by gas chromatography-mass spectrometry (GC-MS). Natural samples includes sediment and suspended particles were analyzed with reliable performance. The establishment of this analytical method will provide a new perspective to explore the geochemical behavior of organic carbon from specific biological origins in the marine environment.