Electrospray ionization - mass spectrometry (ESI-MS) was used for the characterization of uranyl complexed to tributyl phosphate (TBP) and dibutyl phosphate (DBP). The stoichiometry of uranyl with TBP and DBP was determined, and the gas phase speciation was found to be dependent on the cone voltage applied to induce fragmentation on the gas phase complexes. To quantitatively compare the gas phase distribution of species to solution, apparent stability constants were calculated. With a cone voltage of 80V, the apparent stability constants for the complexes UO2(NO3)2•2TBP, UO2(NO3)2(H2O)•2TBP, and UO2(DBP)+ were determined. With a lower cone voltage applied, larger complexes were observed and stability constants for the complexes UO2(NO3)2•3TBP and UO2(DBP)42- were determined.
Revised: November 3, 2015 |
Published: January 21, 2014
Citation
McDonald L.W., J.A. Campbell, and S.B. Clark. 2014.Failure of ESI Spectra to Represent Metal-Complex Solution Composition: A Study of Lanthanide-Carboxylate Complexes.Analytical Chemistry 86, no. 2:1023-1029.PNNL-SA-96226.doi:10.1021/ac401751r