Negative ion chemical ionization mass spectrometry of some nitroso compounds with CO2 as reagent gas

Mass spectra of seven N-nitrosamines and five alkyl nitrites, the O-nitroso compounds, have been obtained by low pressure negative chemical ionization with CO2 as reagent gas. Intense anions were observed at m/z M−32 for N-nitrosamines and at m/z M−30 for alkyl nitrites. Addition products were found at m/z M+12 and M+43 for N-nitrosamines and at m/z M+14 for alkyl nitrites. By using isotopically labeled CO2, it could be shown that the anions at m/z M+12, M+14 and M+43 correspond to [M - H2NO + CO2−, [M − NO + CO2]−, and [M − H + CO2]−, respectively.