Flame ionization of iron and lead

Abstract

The mass spectra of ions in flame ionization detector (f.i.d.) type flames containing iron and lead compounds show that, in addition to metal ions, prominent species of formula (Mo_xH_x+1)⁺ are present which are apparently protonated metal hydroxides. For FeOH₂⁺ and PbOH₂⁺, however, the structure of these species may be identical with those of metal-ion hydrates. This work confirms the presence of Pb⁺ ions in flames to which lead compounds are added, but, in general, metal or metal-containing ions should not affect the saturation current obtainable in an f.i.d, used to detect organometallic compounds. Ionization of iron and lead and their oxides and hydroxides by H₃O⁺ may contribute to atmospheric ionization in the presence of metallic pollutants.