PYROLYSIS CHEMICAL-IONIZATION MASS-SPECTROMETRY OF CELLULOSE ETHERS

Pyrolysis ammonia chemical ionization (PyCI) mass spectrometry was per formed on hydroxyethyl-, hydroxypropyl-, methyl-, hydroxypropylmethyl- , and ethylhydroxyethyl celluloses. The mass peaks in the PyCI mass sp ectra of these cellulose ethers could be assigned to the ions of pyrol ytic dissociation products which form via the [2 + 2 + 2] cycloreversi on and the E(i) elimination pyrolysis pathway. Structural information about the residual amount of nonderivatized cellulose, the relative ch ain length distributions of the substituents in hydroxyalkyl cellulose s, and the end-capping of hydroxyalkyl substituents by alkyl groups in the mixed cellulose ethers is obtained. Interference of secondary pyr olysis products in the PyCI mass spectra is found to be of minor impor tance, especially in the lower mass regions. (C) 1995 John Wiley & Son s, Inc.