Characterization of isopoly tungstate using time-of-flight electrospray mass spectrometry

Electrospray time-of-flight (TOF) mass spectrometry has been carried out on aqueous solutions of isopoly tungstate. A number of factors affecting the speciation of tungstate were studied, including concentration, and pH. The concentrations of the solutions ranged from 10(-2) to 10(-5) M. At all conc entrations studied, the pH range was sufficient to investigate all major sp ecies expected to be in aqueous solution. In all cases, the results obtaine d by electrospray showed changes in speciation which were limited to proton ation and solvation effects, the tungstate core remained intact.