Detection of oxidized organic molecules by CHARON PTR-TOF via soft ammonium ionization
One drawback of Proton Transfer Reaction mass spectrometry (PTR-MS) with H3O+ reagent ions is that oxidized functional groups of organic molecules are often ejected upon protonation. Here we present a novel ammonium adduct ionization mode for (CHARON) PTR-TOFMS that allows for an almost fragmentation free detection of oxidized and highly oxidized organic molecules including hydroxy, carboxy and peroxy functional groups. We demonstrate the ability to qualitatively and quantitatively detect highly oxidized species (#O up to 8) in A.NH4+ mode with an example of a limonene ozonolysis SOA.
Learn more about the novel proprietary SRI reagent ion NH4+ and about CHARON PTR-TOFMS.