On gaseous C 4H 6O 2 compounds in the atmosphere: new insights from collision experiments of the protonated molecules in the laboratory and on aircraft

Abstract

A variety of mass spectrometric methods and complementary theoretical calculations are used to assess the potential contributions of C 4H 6O 2 isomers to the m/ z=87 ion found in a recent atmospheric field study (Int. J. Mass Spectrom. 223/224 (2003) 733). The analysis of high- and low-energy collision experiments suggests that a ca. 1:1:1 mixture of crotonic acid, vinylacetic acid, and methyl acrylate can account for the experimental findings in the field study. For a more concise assessment, further field studies using complementary approaches for the characterization of atmospheric trace components are recommended.