Why is fluorine-18 unstable?

The radioisotope fluorine-18 is the most frequently used isotope for PEPT studies. The nucleus of fluorine-18 is unstable as it is proton rich, as such; a proton converts to a neutron and emits a positron and neutrino. A positron is an antimatter particle which is similar to an electron but has a positive charge.

How does oxygen-18 become fluorine-18?

Fluorine-18 is produced with a cyclotron primarily by proton (1H) irradiation of 18O, a stable naturally occurring isotope of oxygen. When the target is liquid H218O, an aqueous solution of 18F-fluoride ion is obtained; when the target is 18O2 gas, 18F–F2 gas is obtained.

Is fluorine-18 stable or unstable?

Fluorine-18 is the lightest unstable nuclide with equal odd numbers of protons and neutrons, having 9 of each.

What is the difference between o16 and o18?

Oxygen-16 and oxygen-18 differ in the number of neutrons in their nuclei. Oxygen-16 has 8 neutrons, while oxygen-18 has 10 neutrons.

How does fluorine-18 undergo decay?

Fluorine F 18 decays by positron ,(β+) emission and has a half-life of 109.7 minutes. The principal photons useful for diagnostic imaging are the 511 keV gamma photons, resulting from the interaction of the emitted positron with an electron (Table 1).

WHY IS F 18 often used as a radiolabeled?

Fluorine-18 is one of the several isotopes of fluorine that is routinely used in radiolabeling of biomolecules for PET; because of its positron emitting property and favorable half-life of 109.8 min.

How is oxygen-18 formed?

Oxygen is composed of 8 protons, and in its most common form with 8 neutrons, giving it an atomic weight of 16 (16O) — this is know as a “light” oxygen. It is called “light” because a small fraction of oxygen atoms have 2 extra neutrons and a resulting atomic weight of 18 (18O), which is then known as “heavy” oxygen.

Are oxygen-18 and fluorine-18 isotopes?

Fluorine-18 is a radioactive isotope that decays by positron emission to form oxygen-18 with a half-life of 109.7 min. (b) If a sample of glucose containing radioactive fluorine-18 is injected into the blood, what percent of the radioactivity will remain after 5.59 h?

Why is fluorine unstable?

It is very unstable and reactive since it is so close to its ideal electron configuration. It forms covalent bonds with nonmetals, and since it is the most electronegative element, is always going to be the element that is reduced.

Does oxygen 17 and oxygen-18 have the same mass?

Because protons and neutrons are roughly equal in mass, an isotope’s number is equal to the sum of its protons and neutrons. Therefore, oxygen 16 has 8 protons and 8 neutrons, oxygen 17 has 8 protons and 9 neutrons, and oxygen 18 has 8 protons and 10 neutrons.

What is the importance of oxygen-18?

Oxygen-18 in the water or gaseous form serves as a source for short-lived positron-emitting isotope fluorine-18, which allows tracking the processes of cerebral blood flow, glucose metabolism in the central nervous and cardiovascular systems, evaluating the impact of drugs on neuroreceptors.