Investigation of volatile chemicals and their distributions from pyrolysis of chitin by FT-IR and GC–MS

• Chitin was transformed into acetamide, furans and pyrroles by pyrolysis.
• Acetamide was the major volatile chemicals and generated from chitin at the early stage of pyrolysis.
• The effect of pyrolysis temperature on distributions of volatile compounds was investigated.
• Oxygen made the distribution of volatile compounds complicated.
• We proposed the pyrolysis mechanism of chitin for volatile compounds.

This article is focused on investigation of volatile chemicals and their distributions from pyrolysis of chitin. Thermogravimetric analyzer (TG) equipped with differential scanning calorimeter (DSC) was used to investigate the pyrolysis behavior of chitin, and the evolved volatiles were on-line characterized by Fourier transform infrared spectroscopy (FT-IR). Gas chromatography/mass spectrometry (GC–MS) was employed to further identify the volatile chemicals. The main volatiles evolved from the pyrolysis of chitin in vacuum were acetamide, furans and pyrroles, and acetamide was the major product. Pyrolysis temperature in the range of 260–360 °C has litter influence on concentrations and distributions of volatile compounds, which indicated that acetamide was produced by splitting of side constituents at the early stage of pyrolysis. The major volatile compound from pyrolysis of chitin in the presence of oxygen was also acetamide, whereas the distribution of volatile compounds became complicated and the concentration of acetamide decreased.