Patent Number: 042016258
Section: description

ILLUSTRATIVE EXAMPLE A foil of vanadium measuring 20 by 20 mm in size and 0.25 mm thick was bombarded in a cyclotron with .sup.3 helium ions of 14 MeV energy at an intensity of 500 nA for 60 minutes with water cooling. Ten hours after the end of the irradiation, the vanadium foil was dissolved in 5 ml of 40% nitric acid. The solution was treated with 20 ml of a saturated potassium iodate solution and boiled until the color changed from green to yellow. The solution was allowed to cool, was brought to a pH value of 10 with sodium hydroxide solution and was immediately extracted with 40 ml of a 0.1 m solution of 8-hydroxychinolin in chloroform. The organic phase was washed with 20 ml of an aqueous solution set at pH=10 with sodium hydroxide. The organic phase contained only the desired .sup.52 manganese, while all the other radionuclides produced by the nuclear reaction remained in the aqueous phase. The yield of .sup.52 manganese amounted to 6 .mu.Ci per .mu.Ah(6.2.multidot.10.sup.7 s.sup.-1 /C). The chemical yield of the separation process described was from about 50 to 60% at 24 hours after the end of irridation. the radiochemical purity check carried out with a .gamma. spectrometer showed less than 0.1% .sup.54 manganese and 0.1% .sup.51 chromium, referred to the quantity of .sup.52 manganese produced. Contamination with .sup.54 manganese occurs in the nuclear reaction with the chromium contained in very small quantities in the target material. It amounts (at the start) to about 5.times.10.sup.-6 % per ppm of chromium. When a vanadium foil of technical quality with about 500 ppm of chromium is used, .sup.52 manganese is, accordingly, obtained with about 2.5.times.10.sup.-3 % of .sup.54 manganese impurity; whereas, from a very pure vanadium with 2 ppm chromium content, a product is produced that contains only 10.sup.-5 % of .sup.54 manganese. The .sup.52 manganese dissolved in chloroform as an oxinate complex is useful and easily available as a starting material for the preparation of radiochemical or radiopharmaceutical compositions. The manganese oxinate complex can, of course, be readily converted to provide some other manganese compound for uses of .sup.52 Mn in which the chloroform solvent medium is undesirable. Although the invention has been illustrated with reference to a particular illustrative example, it will be understood that variations and modifications of the illustrated example are possible within the inventive concept.