Bh. Mock et al., SOLID-PHASE REVERSIBLE TRAP FOR [C-11] CARBON-DIOXIDE USING CARBON MOLECULAR-SIEVES, Nuclear medicine and biology, 22(5), 1995, pp. 667-670
A simple, maintenance-free trapping technique which concentrates and p
urifies no-carrier-added (CO2)-C-11 from gas targets is described. The
trap requires no liquid nitrogen cooling and has no moving parts besi
des solenoid valves. It employs carbon molecular sieves to adsorb (CO2
)-C-11 selectively from gas targets at room temperature. Nitrogen, O-2
, CO, NO and moisture in the target gas which could interfere with sub
sequent radiochemical steps are not retained. Trapping efficiency of 1
g of sieve for (CO2)-C-11 from a 240 cm(3) target gas dump and helium
Bush cycle is >99%, and the adsorbed (CO2)-C-11 is recovered quantita
tively as a small concentrated bolus from the carbon sieve trap by the
rmal desorption. This durable trap has performed reliably for more tha
n 1 y with a single charge of carbon sieve. It has simplified the prod
uction, and improved the yields of several C-11-radiochemicals at this
laboratory.