Application of off-line pyrolysis with dynamic solid-phase microextraction to the GC-MS analysis of biomass pyrolysis products

摘要

Pyrolysis coupled with dynamic solid-phase micro extraction (Py-SPME) followed by GC-MS analysis wasapplied to the determination of volatile compounds evolved by a micro-scale off-line pyrolysis apparatus, in order to extend the information affordable with this type of analytical equipment.The Py-SPME method witha carboxen/PDMS fiber working in the retracted mode was tested on four biomass samples (switchgrass, sweet sorghum,corn stalk and poplar)for qualitative analysis of semi-volatile pyrolysis products andquantitative determination of main volatiles(C1–C4)pyrolysis products.The developed procedure allowed capturing and analysis of all GC analyzable compounds, without memory effects and with good peakresolution also for early GC-eluting compounds.Twelve main volatile pyrolysis products, including hydroxyacetaldehyde and acetic acid, were successfully quantified; in spite of the intrinsic variabilityintroduced by dynamic SPME sampling, results were relatively accurate and consistent with literature data on bench pyrolysis reactors.