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 chemiions produced in jet fuel combustion in the exhaust of a jet engine and of a burner in the laboratory. The measurements made by a novel quadrupole ion trap mass spectrometer apparatus revealed the presence of three major ion families: ions containing an HSO4− “core” or an NO3− “core”, and “OHC-ions”. The latter which contain C and H atoms and in part also O atoms can be divided 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 molecules and/or ion–molecule reactions of primary negative chemiions with HC and OHC molecules. It is also proposed that HSO4−- and NO3−-containing ions are formed by ion–molecule reactions involving OHC ions and the sulfur- and reactive nitrogen-containing molecules H2SO4, SO3 and NO, NO2, HNO2, HNO3.