“…Comment on the fragmentation of DEDSO and ethyldisiloxane under electron impact is pertinent. The mass spectra of DEDSO [m/z (relative intensity, %)~134 (10), 133 (41), 132 (29), 106 (13), 105 (92), 104 (20), 103 (22), 78 (16), 77 (100), 76 (14), 75 (50), 74 (11), 73 (17), 72 (7)] and of ethyldisiloxane [m/z (relative intensity, %)~106 (11), 105 (60), 104 (10), 78 (12), 77 (100), 76 (30), 75 (48), 74 (9), 73 (17), 72 (8)] consist of signals corresponding to the loss of ethene and of 1-5 or 1-6 H atoms. Both mass spectra were obtained by GC/MS analysis.…”