高寒草甸植物正构烷烃特征分析

Characterization of plant n-alkanes in alpine meadow

为研究高寒草甸植物正构烷烃分布特征,对采自黄河源区高寒草甸的58种植物进行了测定和分析。结果表明,单种植物中正构烷烃的碳数在C8和C40之间,含量分布范围为0.81～22.88mg/kg,其中碳数为C_（27）、C_（29）、C_（31）、C_（33）正构烷烃的含量均较高;总正构烷烃（C_（total））含量变化范围为35.00～78.64mg/kg,长链正构烷烃（C_（25-36））含量范围为16.11～58.68mg/kg,条叶垂头菊中总正构烷烃和长链正构烷烃含量最小,而阿尔泰狗娃花含量最大。58种植物中含量最高的正构烷烃（Cmax）分布特征为：C19有1种,C_（22）有2种,C_（27）有2种,C_（29）有23种,C_（31）有27种,C32有1种,C_（33）有2种。植物中正构烷烃总正构烷烃碳优势指数（CPI_（total））范围为1.07～4.32,CPI25-36范围为1.12～8.20,总的正构烷烃平均碳链长度（ACL_（total））范围为23.52～27.22,ACL_（27-33）范围为28.03～31.07,蜡质指数（P_（wax））变化范围为0.60～0.92。植物中长链正构烷烃丰富,奇数碳含量分布优势明显。

Alpine meadow plants were collected and analysed to characterize the n-alkanes present.The results showed that the carbon number of n-alkanes of individual plants varied from C8 to C40 and n-alkanes content ranged from 0.8 to 22.9 mg/kg.The C27 ,C29 ,C31 and C33 n-alkanes contents were greater than that of remai-ning n-alkanes;total n-alkane （Ctotal ）ranged from 35.0 to 78.6 mg/kg,while the long chain n-alkane （C25-36 ） content ranged from 16.1 to 58.7 mg/kg.The total n-alkane and long chain n-alkane content was highest in Heteropappus altaicus and least in Cremanthodium lineare .Analysis of the n-alkane distribution of the Cmax among 58 plants sampled revealed one species with a Cmax of C19 ,two species with C22 ,two species with C27 ,23 species with C29 ,27 species with C31 ,one species with C32 and two species with C33 .The CPItotal ranged from 1. 1 to 4.3,and the CPI25-36 from 1.1 to 8.2.The ACLtotal ranged from 23.5 to 27.2,and the ACL27-33 from 28.0 to 31.1.The Pmax ranged from 0.6 to 0.9.The sampled plants contained abundant long-chain n-alkanes with a significant odd carbon number preference.