The effect of different pyrolysis temperatures on organic microfossils, vitrain and amber-A comparative study between laser assisted- and Curie Point-pyrolysis-gas chromatography/mass spectrometry

摘要

This study explores the comparability of results of two different pyrolysis methods applied to macromolecular geochemical material: laser-pyrolysis-gas chromatography/mass spectrometry (La-Py-GC/MS) and Curie Point-pyrolysis-gas chromatography/mass spectrometry (CP-Py-GC/MS). Six samples of different fossil (megaspores, prasinophytes, scolecodonts, amber, vitrain) and extant (sporopollenin) biomaterials were analysed at various pyrolysis temperatures by CP-Py-GC/MS and by La-Py-GC/MS. The qualitative composition of the pyrolysates obtained from both methods was similar. However, La-Py-GC/MS produced shorter aliphatic pyrolysis products in almost all samples. Results obtained from megaspores and prasinophytes indicate a laser temperature higher than the highest Curie temperature applied (920 ℃). The application of La-Py-GC/MS was successful for material with a predominantly aromatic structure and/or a high thermal maturity (scolecodonts, vitrain). For extant or immature materials CP-Py-GC/MS appears to be a more suitable method as the applied temperature can be regulated much more accurately.