ISSN:
1076-5174
Keywords:
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
The ammonia chemical ionization (NH3/CI) spectra of phenylpropanoids and substituted phenylalkyl phenyl ethers containing α-hydroxy or α-carbonyl functional groups are discussed. Fragmentation reactions which occur in the temperature range 180-450°C are examined to model pyrolysis mass spectrometric experiments of lignin. Hydroxycinnamyl alcohols and α-hydroxy phenylalkyl phenyl ethers show abundant [M + H - H2O]+ elimination ions and to a lesser extent [M + NH4 - H2O]+ substitution ions while hydroxycinnamic acids and α-carbonyl phenylalkyl phenyl ethers show predominantly [M + H]+ and [M + NH4]+ ions. The interpretation of functional group information is facilitated by using trideuterioammonia (ND3) and [15N] ammonia (15NH3) as reagent gases. Labile hydrogens undergo essentially complete exchange upon ND3/CI and the number of hydroxyl functional groups is readily determined by comparison of the [M + NH4]+ and [M - nH + nD + ND4]+ adduct ions. Incomplete H—D exchange is observed for enolizable and aromatic protons.
Additional Material:
10 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jms.1190300404
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