Chemical ionization of carboxylic acids and esters in negative mode selected ion flow tube – Mass spectrometry (SIFT-MS)

Selected ion flow tube – mass spectrometry (SIFT-MS) is based on chemical reactivity of analytes with reactant ions. The complete understanding all the ion–molecule reactions key to deployment this technology for direct and rapid analysis VOCs in gas phase. In present work, we focused carboxylic acids esters, compounds involved many biochemical processes. negative precursor ions (OH–, O●−, O2●−, NO2– NO3–) 9 21 esters were investigated order provide product rate constants these by SIFT-MS. modelling reaction paths ab-initio calculations supported experimental results provided a better phase reactions. most common mechanism tested molecules deprotonation. However, other specific reactivities, leading formation anion-molecule complexes O2●− particular, are observed. Furthermore, fragmentations families also noticed confirmed O●−. Finally, demonstrated that composition matrix (H2O, CO2) participates secondary determined kinetic nitrogen carrier detection limits eight used SIFT-MS, allowing accurate quantification at ppb level. These contribute enlarge ionization SIFT-MS measurements applications where organic required.