Thermal degradation products of spruce needles

Spruce needles are analysed by in-source pyrolysis (Py)-field ionization (FI) mass spectrography and Curie-point Py-gas chromatography/electron ionization mass spectrometry. The identified thermal degradation products allow the interpretation of the FI mass signals. It could be shown that Py-FI mass spectra of plant materials are representative fingerprints which consist primarily of molecular ions of Py products derived from the thermal degradation of the main constituents of spruce needles such as carbohydrates, lignin, lipids and proteins. Primary building blocks of these biopolymers form characteristic Py products of spruce needles. Furthermore, over 500 different molecular ion species of volatilized, thermostable plant constituents are recorded using FI as soft ionization method. The present study shows that Py-FIMS is suitable for the rapid and comprehensive characterization of complex biological materials, without pretreatment of the sample except of drying and milling. The presented results contribute to the basic knowledge for the evaluation of the causes of the present tree damage.