On the development of a new prototype PTR-ToF-MS instrument and its application to the detection of atmospheric amines

Abstract

Abstract. We herein report on the development of a new prototype PTR-ToF-MS instrument that combines a hollow cathode glow discharge (HCGD) ion source with a focusing ion-molecule reactor (FIMR), which consists of a resistive glass drift tube surrounded by quadrupole rods. The new instrument configuration hybridizes the two main current commercial PTR-ToF-MS instrument designs. We provide a detailed technical description of the new analyzer and its optimized operational settings for detecting volatile amines via proton transfer reactions from hydronium (H3O+) or ammonium (NH4+) ions. We show that the new prototype PTR-ToF-MS instrument is capable of monitoring rapid changes of sticky amines on the timescale of a few seconds and detects atmospheric variations of amines down to single digit pptV levels. Application examples given include the real-time monitoring of i) methylamine emitted from a Chenopodium vulvaria L. plant, ii) small alkylamines in ambient air on site of an agricultural research center (Senter for husdyrforsøk, Ås, Norway), and iii) an industrial amine (2-amino-2-methylpropan-1-ol, AMP) on site and downwind of a carbon dioxide (CO2) capture test center (Technology Centre Mongstad – TCM, Mongstad, Norway).