Identification of tropospheric ions

Abstract

Mass spectrometric measurements of naturally occurring atmospheric ions were performed near ground level at Sapelo Island, Georgia. The sampled ions were then passed through a chamber in which they could be dissociated by multiple collisions with a buffer gas. At low‐collision energies, H 2 O clusters were removed, allowing positive core ions to be identified at masses 18, 60, 80, 94, and 108. At high‐collision energies, positive core ions were dissociated, and the mass of their fragments was used to help determine their identity. Mass 18 is believed to be NH 4 + . Methylpyridine and dimethylpyridine were tentatively identified as the parent neutral species responsible for the core ions observed at mass 94 and 108.