GALLIUM (Gallium; Ga) — chemical element III of group of a periodic system of elements of D. Mendeleyev. Time. number — 31; at. weight — 69,72; shaft. + Z, +2, +1. Has two stable — 69 Ga (60,2%) and 71 Ga (39,8%) — and radioactive short-lived isotopes with mass numbers from 63 to 76. In medicine and biology are suitable for use 66 Ga, 67 Ga, 68 Ga and 72 Ga with half-lives respectively 9,45 hours, 77,9 hours, 68,3 min. and 14,12 hours.
Radioisotopes G. apply with the diagnostic purpose to scanning of bones (in the form of citrate), marrow, a liver, a spleen (in the form of colloid solution of ferric hydroxide) and a brain (in a complex with EDTA).
In medical practice apply hl. obr. 67 Ga received usually by radiation of zinc is more rare germanic, targets protons or deuterons on the accelerator, and 68Ga, received generally from the isotope generator 68 Ge → 68 Ga (see. Generators of radioisotopes ).
67 Ga breaks up with electron capture (100%), letting out at the same time the gamma radiation consisting of 10 lines with energy from 0,091 to 0,88 Mev; 68 Ga — with electron capture (12%) and with emission of positrons (88%) with the maximum energy of 0,77 and 1,90 Mev, and also gamma radiations with energy of 0,51 Mev (176%) and four weak lines (overall yield less than 4%) with energy from 0,31 to 1,88 Mev.
Radioactive treats isotopes with average radio toxicity (see. Isotopes , radioactive).
For measurement of activity of the drugs containing 67 Ga and 68 Ga, and the dose of radiation created by them usually use scintillation counters and ionization chambers (see. Dosimeters , Radio isotope diagnostic units ).
See also Radio isotope diagnosis .
Bibliography: Levin V. I. Receiving radioisotopes, page 66, etc., M., 1972; Standards of radiation safety (NRB — 69), M., 1972; Hayes R. L. Radioisotopes of gallium, in book: Radioactive pharmaceuticals, ed. by G. A. Andrews a. o., p. 603, Oak Ridge, 1966; Nelson B., H ayes R. L. a. Edwards G. L. Distribution of gallium in human tissues after intravenous administration, J. nucl. Med., v. 13, p. 92, 1972.