Charge Exchange Reaction in Dopant-Assisted Atmospheric Pressure Chemical Ionization and Atmospheric Pressure Photoionization

Show full item record



Permalink

http://hdl.handle.net/10138/174484

Citation

Vaikkinen , A , Kauppila , T J & Kostiainen , R 2016 , ' Charge Exchange Reaction in Dopant-Assisted Atmospheric Pressure Chemical Ionization and Atmospheric Pressure Photoionization ' , Journal of the American Society for Mass Spectrometry , vol. 27 , no. 8 , pp. 1291-1300 . https://doi.org/10.1007/s13361-016-1399-8

Title: Charge Exchange Reaction in Dopant-Assisted Atmospheric Pressure Chemical Ionization and Atmospheric Pressure Photoionization
Author: Vaikkinen, Anu; Kauppila, Tiina J.; Kostiainen, Risto
Contributor: University of Helsinki, Faculty of Pharmacy
University of Helsinki, Faculty of Pharmacy
University of Helsinki, Faculty of Pharmacy
Date: 2016-08
Language: eng
Number of pages: 10
Belongs to series: Journal of the American Society for Mass Spectrometry
ISSN: 1044-0305
URI: http://hdl.handle.net/10138/174484
Abstract: The efficiencies of charge exchange reaction in dopant-assisted atmospheric pressure chemical ionization (DA-APCI) and dopant-assisted atmospheric pressure photoionization (DA-APPI) mass spectrometry (MS) were compared by flow injection analysis. Fourteen individual compounds and a commercial mixture of 16 polycyclic aromatic hydrocarbons were chosen as model analytes to cover a wide range of polarities, gas-phase ionization energies, and proton affinities. Chlorobenzene was used as the dopant, and methanol/water (80/20) as the solvent. In both techniques, analytes formed the same ions (radical cations, protonated molecules, and/or fragments). However, in DA-APCI, the relative efficiency of charge exchange versus proton transfer was lower than in DA-APPI. This is suggested to be because in DA-APCI both dopant and solvent clusters can be ionized, and the formed reagent ions can react with the analytes via competing charge exchange and proton transfer reactions. In DA-APPI, on the other hand, the main reagents are dopant-derived radical cations, which favor ionization of analytes via charge exchange. The efficiency of charge exchange in both DA-APPI and DA-APCI was shown to depend heavily on the solvent flow rate, with best efficiency seen at lowest flow rates studied (0.05 and 0.1 mL/min). Both DA-APCI and DA-APPI showed the radical cation of chlorobenzene at 0.05-0.1 mL/min flow rate, but at increasing flow rate, the abundance of chlorobenzene M+. decreased and reagent ion populations deriving from different gas-phase chemistry were recorded. The formation of these reagent ions explains the decreasing ionization efficiency and the differences in charge exchange between the techniques.
Subject: Atmospheric pressure photoionization
Atmospheric pressure chemical ionization
Dopant
Charge exchange
CHROMATOGRAPHY-MASS-SPECTROMETRY
DISCHARGE ION-SOURCE
PROTON-TRANSFER
AROMATIC-HYDROCARBONS
SOLVENT FLOW
APPI
AFFINITY
CLUSTERS
WATER
ELECTROSPRAY
116 Chemical sciences
1182 Biochemistry, cell and molecular biology
114 Physical sciences
Rights:


Files in this item

Total number of downloads: Loading...

Files Size Format View
Vaikkinen_et_al_JASMS_2016_DA_APCI_and_DA_APPI.pdf 412.6Kb PDF View/Open

This item appears in the following Collection(s)

Show full item record