Negative Ion Mass Spectra of Organic Nitriles

Abstract
Negative ion mass spectra organic nitriles have been determined using 1 Torr of methane moderator/reagent gas in a chemical ionization source. The spectra contain abundant (M – 1) ions, and fragmentations are minimal. Ion/molecule reactions with residual oxygen, methane, and between sample molecules and ions form diverse products with low abundances relative to the ( M – 1). Detection limits are comparable with positive ion methods, and for selected compounds, can be several orders of magnitude lower.