Any no-carrier-added 11C-compounds prepared from [11C]CH3I seem to coexist with at least about 0.2 μmol of its non-radioactive form (carrier). In order to elucidate the source of the carrier, 11C]CH3I prepared under various conditions was converted into several 11C-compounds and their specific activities were measured by high performance liquid chromatography. Carbon contamination of LiAlH4 was also examined by gas chromatography. It was shown that only a negligible amount of CO2 was brought with the irradiated target N2 gas and that the carrier amount decreased remarkably with the reduction of the amount and concentration of the LiAlH4THF solution but not to less than 0.2 μmol. The use of Et2O or Pr2O instead of THF was found to give EtOH or PrOH, respectively, together with MeOH, all in small amounts. Hence, the 0.2 μmol carrier can be regarded as being originated in MeOH formed from a trace of THF remaining in the LiALH4 after its drying step.
|Number of pages||7|
|Journal||International Journal of Radiation Applications and Instrumentation. Part|
|Publication status||Published - 1988|
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