Proton irradiation of [18O]O2: production of [18F]F2 and [18F]F2 + [18F] OF2.
The production of 18F electrophilic reagents via the 18O(p,n)18F reaction has been investigated in small-volume target bodies made of aluminum, copper, gold-plated copper and nickel, having straight or conical bore shapes. Three irradiation protocols-single-step, two-step and modified two-step-were used for the recovery of the 18F activity. The single-step irradiation protocol was tested in all the target bodies. Based on the single-step performance, aluminum targets were utilized extensively in the investigation of the two-step and modified two-step irradiation protocols. With an 11-MeV cyclotron and using the two-step irradiation protocol, > 1Ci [18F]F2 was recovered reproducibly from an aluminum target body. Probable radical mechanisms for the formation of OF2 and FONO2 (fluorine nitrate) in the single-step and modified two-step targets are proposed based on the amount of ozone generated and the nitrogen impurity present in the target gases, respectively.
Bishop
A
A
Department of Molecular and Medical Pharmacology, UCLA School of Medicine, USA.
Satyamurthy
N
N
Bida
G
G
Hendry
G
G
Phelps
M
M
Barrio
J R
JR
D000535:Aluminum; D017357:Cyclotrons; D005461:Fluorine / Q000737:chemistry*; D005462:Fluorine Radioisotopes; D005466:Fluorocarbons / Q000737:chemistry; D006801:Humans; D007553:Isotope Labeling / Q000379:methods; D010087:Oxides / Q000737:chemistry*; D010103:Oxygen Isotopes; D010126:Ozone; D011522:Protons; D014055:Tomography, Emission-Computed
D005462:Fluorine Radioisotopes; D005466:Fluorocarbons; D010087:Oxides; D010103:Oxygen Isotopes; D011522:Protons; D005461:Fluorine; D010126:Ozone; C035066:carbon tetrafluoride; C014559:fluorine monoxide; D000535:Aluminum