ION-MOLECULE REACTIONS IN THE SOURCE OF AN ATMOSPHERIC-PRESSURE IONIZATION MASS-SPECTROMETER

Rate equation analysis is performed for the ion-molecule reactions occurring in the source of a corona discharge atmospheric pressure ionization mass spectrometer for the case of bulk nitrogen. The solutions to these equations, together with the model for the space-charge dominated corona discharge source, are used to elucidate the interference effects that exist when multiple impurities are present. The effect of the discharge current on the response of the atmospheric pressure ionization mass spectrometer is also calculated and compared with experimental results.