The halogens as electron scavengers in hydrocarbon flames

The effects of applying electric fields on the mass spectrometric sampling of positive and negative ions from a flame at atmospheric pressure

“…This means that, when a flame sample cools by heat transfer to the nozzle and also during the supersonic expansion, the equilibrium position of (-IX) shifts most for fluorine, but in effect not at all for iodine. That the ion current detected for I À is not altered by sampling has been confirmed [69] by the measured ratio of [I À ]/[e À ] being found to be that expected for equilibrium at the temperature of the flame. Other ions, such as PO À 3 and PO À 2 , whose formation in reaction (-IX) is actually exothermic, have been found in flames [70].…”

Ion chemistry of aluminum and boron in methane–oxygen flames

“…On the other hand, boron is not an effective electron scavenger downstream. The initial large increase of both positive and negative ions upstream was observed previously with other additives (7,8,10,18). It does not imply any new ion production process, but rather a decreased rate of ion loss.…”