Comparative study of specific activity of [11C]methyl iodide: A search for the source of carrier carbon

✍ Scribed by Ren Iwata; Tatsuo Ido; Akira Ujiie; Toshihiro Takahashi; Kiichi Ishiwata; Kentaro Hatano; Makoto Sugahara

• Book ID: 103920117
• Publisher: Elsevier Science
• Year: 1988
• Weight: 641 KB
• Volume: 39
• Category: Article
• ISSN: 0883-2889
• DOI: 10.1016/0883-2889(88)90084-6

✦ Synopsis

Any no-carrier-added "C-compounds prepared from ["C]CH,I seem to coexist with at least about 0.2pmol of its non-radioactive form (carrier). In order to elucidate the source of the carrier, ["C]CH,I prepared under various conditions was converted into several "C-compounds and their specific activities were measured by high performance liquid chromatography. Carbon contamination of LiAIH, was also examined by gas chromatography.

It was shown that only a negligible amount of CO, was brought with the irradiated target N, gas and that the carrier amount decreased remarkably with the reduction of the amount and concentration of the LiAIH,-THF solution but not to less than 0.2 pmol. The use of Et,0 or Pr,O instead of THF was found to give EtOH or PrOH, respectively, together with MeOH, all in small amounts. Hence, the 0.2 pmol carrier can be regarded as being originated in MeOH formed from a trace of THF remaining in the LiALH, after its drying step.