The GC-MS and HPLC methods were used to determine geoporphyrins in the present work. Compounds in HPLC were assigned by coinjections with Gilsonite bitumen

Serpiano oil shale and Boscan oil. Meanwhile the compounds in GC-MS were identified by coinjection with the porphyrin standards which isolated from Gilsonite bitumens

Serpiano oil shale and Boscan oil. The results show that porphyrin distributions in Chinese samples

which were collected from different lacustrine palaeoenvironmentS

are pronounced distinguishable. Samples from fresh water lacustrine are dominated in C

32

C

31

13

15-Ethano CAP. Samples from hypersaline water lacustrine are characterised by unknown CAP com-pounds

C

31

13

15-Ethano CAP. However

the coal samples are dominated in aetio compounds. These divergences imply there are different porphyrin precursors and porphyrin transformations (in water column and early diagenesis) in different palaeoenvironments.