Negative chemiions formed in jet fuel combustion: new insights from jet engine and laboratory measurements using a quadrupole ion trap mass spectrometer apparatus

Measurements were made of mass numbers and composition of negative chemiion s produced in jet Fuel combustion in the exhaust of a jet engine and of a b urner in the laboratory. The measurements made by a novel quadrupole ion tr ap mass spectrometer apparatus revealed the presence of three major ion fam ilies: ions containing an HSO4- "core" or an NO3- "core", and "OHC-ions". T he latter which contain C and H atoms and in part also O atoms can be divid ed into two subfamilies with even and odd mass numbers. It is proposed that the OHC ions are formed by free-electron attachment to HC and OHC molecule s and/or ion-molecule reactions of primary negative chemiions with HC and O HC molecules. It is also proposed that HSO4-- and NO3--containing ions are formed by ion-molecule reactions involving OHC ions and the sulfur- and rea ctive nitrogen-containing molecules H2SO4, SO3 and NO, NO2, HNO2, HNO3. (C) 2000 Elsevier Science Ltd. All rights reserved.