Characterization of carbohydrates in chemical pulps by pyrolysis gas chromatography/mass spectrometry

摘要

A pyrolysis/gas chromatography/mass spectrometry method (Py/GC/MS) was developed to determine the relative carbohydrate composition in chemical pulps. The composition was determined directly from the pyrograms without calibration against any wet-chemical analytical procedure. However, compensation was necessary due to differences in the response factors of the anhydrosugars from glucan and mannan. The pyrolysis temperature range that gave stable values for carbohydrate composition was found to be 500-700℃. Various pre-treatment steps were investigated. It was shown that the treatments affected the analytical results and that milling should be avoided. The Py/GC/MS results agreed very well with results from other analytical methods. However, low levels of mannan (approx. 0.5-1%) were not detected. The main advantages of the method are its simplicity and shorter analysis time compared to any wet-chemical analytical procedures.