秸秆烟尘中正构脂肪醇和甾醇的碳同位素组成  

The compound-specific carbon isotope compositions of n-alkanols and sterols in smoke from crop residue combustion

作　　者：刘刚[1,2] 李久海[1,2] 徐慧[1,2] 李中平[3] 李立武[3] LIU Gang;LI Jiu-hai;XU Hui;LI Zhong-ping;LILi-wu(Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Nanjing University of Information Science & Technology, Nanjing 210044, China;School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing 210044, China;Lanzhou Center for Oil and Gas Resources, Institute of Geology and Geophysics, Chinese Academy of Sciences, Lanzhou 730000, China)

机构地区：[1]南京信息工程大学江苏省大气环境与装备技术协同创新中心,江苏南京210044 [2]南京信息工程大学环境科学与工程学院,江苏南京210044 [3]中国科学院地质与地球物理研究所兰州油气资源研究中心,甘肃兰州730000

出　　处：《中国环境科学》2017年第5期1735-1740,共6页China Environmental Science

基　　金：国家自然科学基金项目(41073019)

摘　　要：选取稻草、麦秸和玉米秸进行室内模拟燃烧试验,用气相色谱/稳定同位素在线分析系统(GC/C/IRMS)测定了烟尘中正构脂肪醇和甾醇的单体碳同位素比值.结果显示:在稻草明火烟尘中,正构脂肪醇(C20~C30)和甾醇(胆固醇、菜油甾醇、豆甾醇、β-谷甾醇)与稻草δ^(13)C值之差(Δ^(13)C)的平均值分别为-1.3‰、+0.7‰.在稻草闷烧烟尘中,两类化合物的Δ^(13)C平均值分别为-1.4‰、+1.1‰.在麦秸明火烟尘中,正构脂肪醇和甾醇单体的Δ^(13)C平均值分别为+2.4‰、+0.5‰.在麦秸的闷烧烟尘中,两类化合物的Δ^(13)C平均值分别为+3.0‰、+1.7‰.在玉米秸的明火烟尘中,两类化合物的Δ^(13)C平均值分别为-2.5‰和+0.7‰.在玉米秸闷烧烟尘中,两类有机物的Δ^(13)C平均值分别为-3.8‰、+1.8‰.3类秸秆烟尘中的正构脂肪醇和甾醇均发生了明显的碳同位素分馏.秸秆闷烧比明火燃烧更有利于烟尘中此两类有机物发生碳同位素分馏.这对识别气溶胶中以秸秆燃烧为来源的这两类有机物有参考意义.Crop residues of rice,wheat and maize were burned under conditions simulating open combustion.Compound specific carbon isotopic ratios(δ13C)of n-alkanols(C20-C30)and sterols(cholesterol,campesterol,stigmasterol,andβ-sitosterol)in smoke from biomass burning were determined.The results showed that the mean distinction(Δ13C)values ofδ13C ratios for n-alkanols and sterols between flaming smoke from rice straw and the fuel were-1.3‰and+0.7‰,respectively.The meanΔ13C values in smoldering smoke from the fuel were-1.4‰and+1.1‰,respectively.Moreover,the meanΔ13C values for the two groups of compounds in flaming and smoldering smoke from wheat straw were+2.4‰,+0.5‰,and+3.0‰,+1.7‰,respectively.The meanΔ13C values for the two types of compounds in flaming and smoldering smoke from maize stover additionally were-2.5‰,+0.7‰,and-3.8‰,+1.8‰,respectively.Significant isotopic fractionations occurred in both n-alkanols and sterols in smoke from all three sorts of crop residues.Smolder was propitious to isotopic fractionation in the compounds from smoke relative to flame burning.This may have significance for identifying n-alkanol and/or sterol derived from crop residue burning in atmospheric particles.

关 键 词：秸秆 烟尘 正构脂肪醇 甾醇 碳同位素 

分 类 号：X131.1[环境科学与工程—环境科学] X511