ELECTRON-IMPACT MASS-SPECTROMETRY OF CHOLESTEROL IN SUPERSONIC MOLECULAR-BEAMS

The effect of vibrational supercooling on the electron impact mass spectrometry of cholesterol was studied in supersonic molecular beams. An extensive mass spectral simplification was observed at 20 eV electron energy. The parent undissociated molecular ion becomes the dominant peak even at 70 eV electron energy but the conventional complex fragmentation pattern is retained in spite of the large vibrational cooling. Some of the unique aspects of electron impact mass spectrometry in supersonic molecular beams are mentioned. © 1990 American Chemical Society.