Laser micropyrolysis analysis of single maceral compositions within the coal

Vitrinite and resinite are important macerals within the coal. To understand their chemical compositions and structures is of great significance for the evaluation of hydrocarbon potential. The combination of optical microscope and modified laser micropyrolysis GC-MS technique was employed to analyze the vitrinite and resinite within a Paleo- gene coal of Honghe region of Yunnan Province. The pyrolyzates have shown to have the ubiquitous mono and diaro- matic hydrocarbons,diterpenoids as well as n-alkene / ane doublets for both of vitrinite and resinite,among which,the similar distribution of aromatic hydrocarbons and diterpenoids were obvious,and abundant norpimarane and phyllocla- dane were derived from gymnospermae,especially contributed by conifer resins. However,the distributions of aliphatic hydrocarbons and hopanoids in the pyrolyzates were distinct. The successful application of laser micropyrolysis indi- cates it is a micrometer scale method to recognize hydrocarbon generation characteristics of various macerals within a single sample,and thus make it possible to identify effective hydrocarbon-generation macerals. In addition,compared with conventional geochemical techniques,the superiority of laser micropyrolysis GC-MS technique was discussed as well.