Geochemical features and sources of hydrocarbons and fatty acids in soils from the McMurdo Dry Valleys in the Antarctic
Geochemical features and sources of hydrocarbons and fatty acids in soils from the McMurdo Dry Valleys in the Antarctic
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DOI：
10.1016/j.polar.2010.04.001
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发表时间：
2010-08
期刊：
影响因子：
1.8
通讯作者：
G. Matsumoto;Eisuke Honda;Kazuhiko Sonoda;Shuichi Yamamoto;T. Takemura
中科院分区：
文献类型：
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作者：
G. Matsumoto;Eisuke Honda;Kazuhiko Sonoda;Shuichi Yamamoto;T. Takemura
我们研究了南极麦克默多干谷土壤样本中碳氢化合物和脂肪酸的地球化学特征和化合物特异性 (CS)-δ13C，以阐明其来源生物及其环境特征。土壤样品中的总有机碳含量极低，反映出生物体所处的环境极其恶劣。发现了碳链长度从 n-C14 到 n-C38 且以奇数碳数为主的正构烷烃，以及正烯烃（n-C23:1 到 n-C27:1）。样品中检测到碳链长度从 n-C10 到 n-C30 且以偶碳数为主的正链烷酸，以及少量支链（异和反异）和正链烯酸。长链正构烷烃（n-C20至n-C29）的CS-δ13C值范围为-30.4至-26.6‰。短链碳数（n-C14至n-C19）-27.7至-21.7‰正构烷酸的CS-δ13C值远高于长链碳数（n-C20至n-C30，-32.5至-25.3‰）。长链正构烷烃和正构烷酸的地球化学特征和CS-δ13C值表明它们起源于该地区冰前和间冰期的地衣和/或维管植物残骸，而短链正构烷酸则来自微藻和蓝藻残骸。 CS-δ13C 值表明它们源自麦克默多干谷地区冰前和间冰期寒冷干燥环境中的裸子植物和/或 C4 植物。
We studied the geochemical features and compound-specific (CS)-δ13C of hydrocarbons and fatty acids in soil samples from the McMurdo Dry Valleys in the Antarctic to elucidate their source organisms and characteristics of their environments. Total organic carbon contents in soil samples were extremely low reflecting extremely harsh environments for organisms. Normal-alkanes ranging in carbon chain length from n-C14to n-C38with the predominance of odd-carbon numbers were found, together with n-alkenes (n-C23:1to n-C27:1). Normal-alkanoic acids ranging in carbon chain length from n-C10to n-C30with the predominance of even-carbon numbers were detected in the samples, along with small amounts of branched (iso and anteiso) and n-alkenoic acids. CS-δ13C values of long-chain n-alkanes (n-C20to n-C29) ranged from −30.4 to −26.6‰. CS-δ13C values of n-alkanoic acids with short-chain carbon numbers (n-C14to n-C19) ranging from −27.7 to −21.7‰ were much higher than those of long-chain carbon numbers (n-C20to n-C30, −32.5 to −25.3‰). The geochemical features and CS-δ13C values of long-chain n-alkanes and n-alkanoic acids revealed that they are originated from lichen and/or vascular plant debris from the pre- and inter-glacial periods in this region, whereas short-chain n-alkanoic acids are come from microalgae and cyanobacterial debris. CS-δ13C values suggest that they are derived from gymnosperms and/or C4plants in the cold and dry environments of the pre- and inter-glacial periods of the McMurdo Dry Valleys region.