两种典型现代植物叶片及其混合物长链正构烷烃分子分布特征及其意义

Gas chromatogram (GC) analysis of molecular distribution of long-chain n-alkanes derived from modern leaves of Pinus massoniana and Zea Mays (typical representative of coniferals and cultivated plant in subtropical China, respectively) and their half-to-half mixture clearly demonstrates that no detectable long-chain n-alkanes can extracted from the pine needle of Pinus massoniana, however, the concentrations of long-chain n-alkanes derived from leaves of Zea Mays are extremely high. More interesting, long-chain n-alkanes extracted from half-to-half mixture of leaves of Pinus massoniana and Zea Mays have very similar molecular distribution characteristics as long-chain n-alkanes derived from Zea Mays. These results indicate that it must be more cautious to employ molecular distribution characteristics of sedimentary long-chain n-alkanes derived from terrestrial higher plants as indicator of paleovegetational types or input ratios of trees and grasses, considering the significant differences of productivity of long-chain n-alkanes among plant species.