海相烃源岩中一个新多环芳烃系列的发现及其潜在意义

Identification of a Novel Polycyclic Aromatic Hydrocarbon Series in Marine Source Rocks and its Potential Significance

在下扬子盆地海相古生界烃源岩的芳烃馏分中检测到一个新的多环芳烃同系物：烷基苯并［ｅ］芘和烷基苯并萤蒽，其特征碎片为ｍ／ｚ２５２＋１４ｎ（ｎ＝０～３）。根据不同样品中ｍ／ｚ２５２和ｍ／ｚ２６６质量色谱图中不同化合物相对丰度的变化及其质谱特征初步确认，ｍ／ｚ２６６质量色谱图上ａ，ｂ两峰群属于甲基苯并萤蒽的同系物，而ｃ，ｄ两峰群则属于甲基苯并［ｅ］芘的同系物。研究发现，ｃ／ｄ比值与镜质体反射率之间具有良好的正相关性，表明甲基苯并［ｅ］芘４个异构体相对丰度的变化具有潜在的成熟度意义。

A novel polycyclic aromatic hydrocarbon homologs that are alkyl benzo(e)pyreneand alkul benzoflouranthene series, with particular ions m/ z252+14n(n= 0～3), have been identified in the Mesozoic and Pafeozoic marine source rocks from lower Yangzhi basin. Based on the relative abundances of different compounds in m/ z252 and m/ z266 mass chromatograms and theirmass spectra, a and b peaks may be methyl benzoflouranthene homologues and c and d peaks maybelong to methyl benzopyrene. ln addition, there is a positive relationship between the ratio of c to dand vitrinite reflectances (Ro), it means that the changes of relative abundances of four methylbenzopyrene isomers have potential mature significance.