Fluorine-18 4226265 224104470 2008-07-07T09:38:01Z 58.110.203.97 {{Infobox isotope| background = #eee| text_color = | isotope_name = Fluorine-18| isotope_filename = | alternate_names = Fluorine-18| mass_number = 18| symbol = F| num_neutrons = 9| num_protons = 9| abundance = [[Radioisotope]]| halflife = 109.771(20) [[minute|min]]| decay_mode1 = [[Positron emission]]| decay_energy1 = 1.656| decay_product = Oxygen-18| decay_symbol = Oxygen| decay_mass = 18| mass = 18.0009380(6)| spin = 1+| excess_energy = 873.431| error1 = 0.593| binding_energy = 137369.199| error2 = 0.593| }} '''Fluorine-18''' is a [[fluorine]] radioisotope which is an important source of [[positron]]s. It has a mass of 18.0009380(6) u and its [[half-life]] is 109.771(20) minutes. Fluorine-18 is an important isotope in the [[radiopharmaceutical]] industry, and is primarily synthesized into [[fluorodeoxyglucose]] (FDG) for use in [[positron emission tomography]] (PET scans). It is substituted for [[hydroxyl]] and used as a tracer in the scan. Its significance is due to both its short half-life and the emission of positrons when decaying. In the radiopharmaceutical industry, it is made using either a [[cyclotron]] or [[linear particle accelerator]] to bombard a target, usually of pure or enriched [[oxygen-18]]-water <ref>Fowler J. S. and Wolf A. P. (1982) The synthesis of carbon-11, fluorine-18 and nitrogen-13 labeled radiotracers for biomedical applications. Nucl. Sci. Ser. Natl Acad. Sci. Natl Res. Council Monogr. 1982.</ref> with high energy [[protons]] (typically ~18 MeV). Fluorine-18 is often substituted for hydroxyl due to similar [[steric]] and [[electrostatic]] properties. This may however be problematic in certain applications due to possible changes in molecule [[polarity]]. [[Category:Fluorine]] [[Category:Isotopes]] <references/>