地质环境中生物标志物GDGTs分析技术研究进展

甘油二烷基甘油四醚脂（GDGTs）是一类来自于微生物细胞膜脂的新兴生物标志物，广泛存在于海洋、湖泊、土壤、泥炭等环境。在活体细胞中，GDGTs通常以完整极性膜脂（IPL-GDGTs）的形式存在，而在地质环境中主要以脱去极性头基的核心脂（CL-GDGTs）的形式存在。CL-GDGTs结构稳定、不易降解，并且对环境变化响应敏感，因此被认为是重建古气候-古环境变化的有力工具。GDGTs结构复杂、种类多样，在环境中的含量通常较低且常与其他化合物共存，因此分析难度较高，现有技术和方法在其分离、纯化、定量等方面仍然面临挑战。本文总结了近年来GDGTs在分析技术方面的研究进展，概述了GDGTs的分类与结构，对环境中IPL-GDGTs和CL-GDGTs的分离、纯化等方法进行总结和比较，其中CL-GDGTs可选择多种提取方法，而极性较强、热稳定性较差的IPL-GDGTs应尽量选取Bligh-Dyer提取法。普通的分离、纯化通常采用柱层析法，而涉及GDGTs单体分离时，一般采用制备液相色谱法。液相色谱-质谱、核磁共振波谱、气相色谱-同位素比值质谱是GDGTs含量测定、结构鉴定、同位素分析的主要分析手段。本文评述了现有方法的特点和不足，并在此基础上，提出了GDGTs分析技术的发展方向，以期为地质环境中GDGTs的分析研究提供启示和参考。

Research Progress in Analytical Methods of Biomarker GDGTs in Geological Environments

Glycerol dialkyl glyceryl tetraethers (GDGTs) are a class of environment biomarkers that are widely found in the environment of oceans, lakes, soils, and peat. GDGTs usually exist as intact polar lipids (IPL-GDGTs) in living cells, while they exist as core lipids stripped of polar head groups (CL-GDGTs) in geological environments. CL-GDGTs are structurally stable and sensitive to environmental changes and are considered to be a powerful tool for reconstructing palaeoclimate-palaeoenvironmental changes. GDGTs are structurally complex and diverse, coexisting with other compounds and present low contents, which brings challenges in analysis, especially in separation, purification, and quantification. This article summarizes the classification and structure of GDGTs, and presents a summary and comparison of methods for the separation and purification of IPL-GDGTs and CL-GDGTs in the environment. Multiple extraction methods can be used for CL-GDGTs, while the polar and thermally unstable IPL-GDGTs are preferably extracted using the Bligh-Dyer method. This article reviews the characteristics and limitations of various analysis methods, including liquid chromatography-mass spectrometry, nuclear magnetic resonance spectroscopy, and gas chromatography-isotope ratio mass spectrometry. The BRIEF REPORT is available for this paper at http://www.ykcs.ac.cn/en/article/doi/10.15898/j.ykcs.202306100077.