New ion chemistry methods for rapid mass spectrometric monitoring of atmospheric biogenic volatile organic compounds responsible for air pollution

The field of instrumental monitoring of biogenic volatile organic compounds (BVOCs) is currently an important area of research in mass spectrometry. Present techniques allow off-line analysis of air samples (e.g. TD-GC/MS) whilst the available on-line techniques (proton transfer reaction mass spectrometry, PTR-MS) can quantify only the total concentration of several isomers of important non-methane BVOCs represented by mono- and sesquiterpenenes. The aim of the proposed project is to develop an analytical technique that will allow selective monitoring of individual isomers of mono- and sesquiterpenes in real time (<1 s) corresponding to rate of change of local wind speed. One proposed approach is to use soft chemical ionisation techniques, selected ion flow tube mass spectrometry, SIFT-MS and selected ion flow drift tube mass spectrometry SIFDT-MS and to resolve terpene isomers on the basis of different product ion fragmentation patterns enhanced by collision induced dissociation directly in the drift tube. Complementary research will use thermal desorption and fast GC.