Electron impact and chemical ionization mass spectra of catechol derivatives from insect cuticle

Abstract

Electron impact and isobutane chemical ionization mass spectra of a series of catechol derivatives isolated from hydrolysates of insect cuticle were studied. Electron impact mass spectrometry resulted in sufficient information for the identification of all the compounds. Furthermore, characteristic fragmentation patterns were demonstrated, which allow classification of the catechol derivatives according to the substituent next to the aromatioring of the aliphatic sidechain. By chemical ionization mass spectrometry [M + H]+ions were the base peak in most spectra, but for some compounds [M + H]+ was absent, and [M + H - H2O]+ the base peak. In many of the CI spectra [2M + H]+ ions were present and in one case [3M + H]+. Chemical ionization mass spectrometry was unsuitable for the identification of the catechol derivatives investigated.