title: In-target produced [11C]methane: Increased specific radioactivity.
abstract: The (14)N(rho, alpha)(11)C reaction on N(2)-O(2) or N(2)-H(2) gaseous systems as targets in proton bombardment allows for the production of [(11)C]CO(2) and [(11)C]CH(4.) We report the target production of [(11)C]CH(4) and the gas phase iodination to produce [(11)C]CH(3)I with high specific radioactivity (SA). SA was calculated for four different radiopharmaceuticals produced in-house from both target produced [(11)C]CO(2) and [(11)C]CH(4.) For [(11)C]raclopride we obtained an average SA of 3908 GBq/mumol (106000 Ci/mmol) at the end of bombardment for the last 52 productions, which is a 32-fold increase compared to when using the in-house [(11)C]CO(2) target.
authors.affiliation: Department of Clinical Neuroscience, Psychiatry Section, Karolinska Institutet, Karolinska University Hospital, S-17176 Stockholm, Sweden.
authors.forename: Jan
authors.initials: J
authors.lastname: Andersson
authors.forename: Phong
authors.initials: P
authors.lastname: Truong
authors.forename: Christer
authors.initials: C
authors.lastname: Halldin
mesh_terms: D002245:Carbon Dioxide / Q000737:chemistry*; D002250:Carbon Radioisotopes; D005740:Gases; D054879:Halogenation; D006847:Hydrocarbons, Iodinated / Q000138:chemical synthesis; D007553:Isotope Labeling / Q000379:methods*; D008697:Methane / Q000737:chemistry*; D020891:Raclopride; D011851:Radioactivity; D019275:Radiopharmaceuticals
chemical_list: D002250:Carbon Radioisotopes; D005740:Gases; D006847:Hydrocarbons, Iodinated; D019275:Radiopharmaceuticals; D002245:Carbon Dioxide; D020891:Raclopride; C014055:methyl iodide; D008697:Methane