The static secondary ionization mass spectrometry (SIMS) spectrum of tri-n-butyl phosphate (TBP) on a variety of basalt and quartz samples is affected by the chemical composition of the mineral surface. When TBP is adsorbed on Fe(II)-bearing surfaces, the compound undergoes concomitant H - abstraction and reduction, followed by the elimination of two C 4H 8 molecules to form an ion at m/z 137 +. When TBP is adsorbed to quartz or other nonreducing surfaces, it merely undergoes protonation and elimination of three C 4H 8 molecules to form H 4PO 4 +. When TBP is adsorbed to Fe(III)-bearing surfaces, it undergoes H - abstraction and elimination of two C 4H 8 molecules, to form an ion at m/z 153 +. These conclusions are supported by model studies that employed FeO, Fe 20 3, TBP, and tributyl phosphite. The results show that the SIMS spectrum is very sensitive to the mode of TBP adsorption on the mineral surface.
|Original language||English (US)|
|Number of pages||10|
|Journal||Journal of the American Society for Mass Spectrometry|
|State||Published - Mar 1995|
ASJC Scopus subject areas
- Structural Biology