Characterization of Japanese lacquer liquid and films by means of evolved gas analysis-ion attachment mass spectrometry

Abstract

We investigated the thermal decomposition of Japanese lacquer liquid and films, which are non-volatile complex natural materials, by means of evolved gas analysis-ion attachment mass spectrometry. The thermal decomposition products are identified by analysis of the mass spectra of degraded samples. The mass chromatogram (pyrogram) of the products generated at various temperatures with kinetic treatments is informative for the characterization of lacquer materials. The H₂O pyrogram (obtained in selected-ion-monitoring mode) of a Japanese lacquer film indicated two stages of water release—vaporization and intramolecular H₂O elimination—and the kinetics of these two processes were studied. Plots of temperature versus signal intensity at m/z 25 gave constant slopes and provided apparent activation energies of 41.4 and 171 kJ mol⁻¹, respectively, for the two processes.