Production of [13N]ammonia applicable to low energy accelerators

Nucl Med Biol. 1994 Oct;21(7):987-96. doi: 10.1016/0969-8051(94)90089-2.

Abstract

We have developed a technique for the rapid conversion of the nitrogen-13 induced in a graphite target into nitrogen oxides. This was accomplished by heating the graphite target in a stream of pure oxygen at 800 degrees C. Less than 20% of the radioactivity was found in the form of [13N]nitrogen. The rest of the radioactivity was efficiently trapped in a solid-phase medium that consisted of an aqueous solution of 5% NaOH dispersed in silica gel. The radioactivity from this solid-phase medium was eluted with water (94% recovery) and found to be in the form of 13NO2- (99%). This was subsequently converted to [13N]ammonia with Raney-nickel, either by a conventional liquid-phase reduction with an overall conversion efficiency to ammonia of 45%, or by an incorporation of the Raney-nickel into the solid-phase medium. The latter system resulted in an overall conversion efficiency to ammonia of 37 +/- 9%, with a radiochemical purity of nearly 100% and a synthesis time under 17 min.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Ammonia / chemical synthesis*
  • Ammonia / chemistry
  • Chromatography, Gas
  • Graphite / chemistry
  • Nitrogen Radioisotopes / chemistry*
  • Particle Accelerators*
  • Radiochemistry

Substances

  • Nitrogen Radioisotopes
  • Ammonia
  • Graphite