石油中饱合烃类的喇曼特征

The Characteristics of Raman Spectrometry for the Saturated Hydrocarbons in Oil

本文试通过一些饱合烃类标样的喇曼分析，总结出石油中饱和烷烃组分的最大喇曼特征是在2700～2970cm^-1区域有一系列强烈的喇曼效应，有三种情况：1）直链烷烃类是以-CH^3链基对称喇曼效应（约2872cm^-1）最强；2）带异构骨架链烷烃类是以-CH链基喇曼效应（约2911cm^-1）最强；3）环烷烃类是以-CH2链基对称喇曼效应（约2857cm^-1）最强。另外异构骨架在748cm^-1处有一强的喇曼效应，烷烃环基在804cm。处有一个强的喇曼效应。并发现不同的烃或烃混合物，若结构基团相同，喇曼谱图也相同；在混合烃组分（或烃类包裹体）的喇曼谱图中2905～2921cm^-1间喇曼峰应是-CH基团，而不能单作甲烷存在的证据。

The Raman spectrometric analysis of some standard samples of the saturated hydrocarbons has shown that there is a series of strong peaks in the Raman spectrum band of 2700-2970cm^-1 for the saturated hydrocarbons in petroleum. They include the max -CH3 characteristic peak （2872±cm^-1） for the n-alkanes, the max -CH characteristic peak （2911±cm^-1） for iso-alkanes and the max -CH2 characteristic peak （2857±cm^-1） for cyclic alkanes. In addition, there is a peak of 748 cm^-1 for iso-alkanes and a peak of 804 cm^-1 for cyclic alkanes respectively. In summary, it is indicated that the hydrocarbon compounds with the same functional group show the similar distribution of Raman spectra, while the Raman peak in 2905-2921 cm^-1 only represents the characteristic peak of -CH functional group of the hydrocarbon mixture or hydrocarbon inclusions rather than that of the CH4.