Synthesis of [C-11]methanol on alumina column for production of [C-11]methyl iodide

[C-11]CH3OH was prepared on an Al2O3 column impregnated with ethereal LiAlH 4 by direct trapping of [C-11]CO2 from the irradiated target gas, followed by hydrolysis with dilute phosphoric acid and removal of the product with c arrier gas. Both the efficiency of trapping of [C-11]CO2 and the conversion yield of LiAl[C-11]methylate complex into radiomethanol were over 95%. The apparatus is simple because of the absence of low temperature cooling unit s. Using this method, coupled on-line with an HI impregnated Al2O3 column f or [C-11]CH3I production [1], the synthesis time is shortened by approx. 6 minutes.