State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Shandong Key Laboratory of Eco-Environmental Science for Yellow River Delta, Binzhou University, Binzhou, Shandong Province 256600, China.
State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
Sci Total Environ. 2014 Mar 1;473-474:410-21. doi: 10.1016/j.scitotenv.2013.10.066. Epub 2013 Dec 31.
The distribution and compound-specific carbon isotope ratios of n-alkanes and fatty acids in a sediment core (63 cm) collected from Lake Dianchi were examined to investigate organic matter sources in the eutrophic lake. Fatty acids included free and bound fatty acids. The carbon isotope compositions of individual n-alkanes and fatty acids from Lake Dianchi sediments were determined using gas chromatography/isotope ratio mass spectrometry (GC-IRMS). The δ(13)C values of individual n-alkanes (C16-C31) varied between -24.1‰ and -35.6‰, suggesting a dominance of (13)C-depleted n-alkanes that originated from C3 plants and lacustrine algae. Fatty acids from the sediment extracts were analyzed for their abundances and carbon isotopic compositions. Molecular and isotopic evidence indicates that most of the short-chain fatty acids from Lake Dianchi sediment extracts are sourced from intense microbial recycling and resynthesis of organic matter. Long-chain free fatty acids are mainly derived from terrestrial sources. However, long-chain bound fatty acids are sourced from a combination of terrestrial organic matter, bacteria and algae, with the contribution from algal sources higher in the hypereutrophic stage.
从滇池采集的 63 厘米深的沉积物岩芯中，分析了正构烷烃和脂肪酸的分布及碳同位素比值，以研究富营养化湖泊中的有机质来源。脂肪酸包括游离脂肪酸和结合脂肪酸。利用气相色谱/同位素比质谱仪（GC-IRMS）测定了滇池沉积物中单个正构烷烃和脂肪酸的碳同位素组成。单个正构烷烃（C16-C31）的 δ(13)C 值在-24.1‰至-35.6‰之间，表明源自 C3 植物和湖生藻类的（13）C 贫化的正构烷烃占主导地位。对沉积物提取物中的脂肪酸进行了丰度和碳同位素组成的分析。分子和同位素证据表明，滇池沉积物提取物中的大多数短链脂肪酸主要来源于微生物的强烈循环和有机质的重新合成。长链游离脂肪酸主要来源于陆地源。然而，长链结合脂肪酸则来自陆地有机质、细菌和藻类的综合贡献，在富营养化阶段，藻类的贡献更高。
