title: Solid-phase reversible trap for [11C]carbon dioxide using carbon molecular sieves.
abstract: A simple, maintenance-free trapping technique which concentrates and purifies no-carrier-added 11CO2 from gas targets is described. The trap requires no liquid nitrogen cooling and has no moving parts besides solenoid valves. It employs carbon molecular sieves to adsorb 11CO2 selectively from gas targets at room temperature. Nitrogen, O2, CO, NO and moisture in the target gas which could interfere with subsequent radiochemical steps are not retained. Trapping efficiency of 1 g of sieve for 11CO2 from a 240 cm3 target gas dump and helium flush cycle is > 99%, and the adsorbed 11CO2 is recovered quantitatively as a small concentrated bolus from the carbon sieve trap by thermal desorption. This durable trap has performed reliably for more than 1 y with a single charge of carbon sieve. It has simplified the production, and improved the yields of several 11C-radiochemicals at this laboratory.
authors.affiliation: PET Radiochemistry, Indiana University School of Medicine, Department of Radiology, Indianapolis 46202-5121, USA.
authors.forename: B H
authors.initials: BH
authors.lastname: Mock
authors.forename: M T
authors.initials: MT
authors.lastname: Vavrek
authors.forename: G K
authors.initials: GK
authors.lastname: Mulholland
mesh_terms: D002245:Carbon Dioxide / Q000302:isolation & purification*; D002250:Carbon Radioisotopes; D002849:Chromatography, Gas; D002850:Chromatography, Gel; D007553:Isotope Labeling
chemical_list: D002250:Carbon Radioisotopes; D002245:Carbon Dioxide