脂肪酸单体碳同位素的沉积学记录及其环境意义

湖泊/水库沉积物是有机化学领域的重要研究载体,与其他自然记录比较,它具有信息丰富、时间分辨率高、记录连续性好和覆盖面广等优点。自20世纪80年代以来,在古环境/古气候的研究中,沉积物有机质分子的标志物研究发挥了无可取代的作用。脂肪酸及其单体碳同位素的分布特征与环境意义是目前研究热点。以沉积物为研究载体,采用文献荟萃的方法,探讨了脂肪酸及其单体碳同位素技术在有机质溯源、流域内植被的恢复和气候的反演等方面的研究进展。结果表明:脂类化合物在来源上存在重叠,脂肪酸的研究可以作为正构烷烃分子标志物研究的补充。与单体碳同位素组成特征的联合应用,能够准确地对沉积有机质进行溯源,可以充分揭示保存在陆源脂肪酸中的气候环境信息,为指示气候和环境变化提供重要的线索。在重建区域性的气候和环境状况方面具有广阔的应用前景。

Fatty Acid Distribution and Compound-Specific Characteristics of Carbon Isotopic Records in the Sediments and Environmental Significance

Lake sediment is an important media for molecular organic chemistry research.It has the advantages such as storing large amount of information,high temporal resolution and wide geographical coverage.Since the 1980s,the sedimentary organic matter molecular geochemistry in the study of paleoclimate has played an irreplaceable role.The investigation of global change has focused on the fatty acid and its compound-specific carbon isotopic distribution.Using the methods of extensive search of literatures and summaries,we discussed the literatures of fatty acid and its compound-specific carbon isotopic distribution for the identification of organic matter resources,reconstruction of vegetation and recovery of paleovegetation and paleoclimate.The result shows that the lipid compound has some superpositions in source.The research of fatty acids can be the supplements of n-alknes.And the combination with the compound-specific characteristics of carbon isotopic can trace the organic matter accurately.It can not only reveal the climate and environment information stored in the terrestrial fatty acid but also provide important clues to indicate the climate and environmental changes.It has a broad application prospect in the reconstruction of vegetation,regional climate and environmental conditions.