[1-11C] DL-valine, a potential pancreas-imaging agent.

Abstract

Rh on Al2O3 model catalysts were made by using a flat, elec. conducting support consisting of a thin film of aluminum oxide on an Al foil. Rh was applied in the same way as is usual in the prepn. of powder catalysts, by adsorption from an aq. soln. of RhCl3. The catalysts were studied with monochromatic XPS, static secondary ion mass spectrometry (SIMS), and Rutherford backscattering spectrometry. Because the systems have elec. cond., XPS spectra of high resoln. are obtained while informative mol. clusters of the type RhCl- and RhOn- appear in static SIMS. Angle-dependent XPS spectra of Rh and Al yield an effective layer thickness of Rh, as well as the extent to which the support is covered. RBS indicates that the Rh concn. is in the order of 1015 atoms/cm2.