PREPARATION OF ~(123)I AND ITS FAST LABELING

Bombardments of 26 MeV α beam on antimony of natural abundance is carried out on the 1.2m cyclotron in Atomic Energy Institute to produce iodine-123 by the reaction 121Sb (α, 2n) 123I. A technique of selective adsorption of iodine by platinum coated copper is used in a chromatographric column to separate and concentrate iodine-123. The final product is. in the form of Na123I solution with a radiochemical purity of>99% and an overall chemical recovery of > 95 %. At the end of bombardment, the ratio of major radio-impurity 124I to the product 123I is less than 1.4%. The process can be completed within 4 hours. The 123I is then used for the fast labeling of an adrenal imaging agent I-6β -Iodo-methyl-19-norcholest-5(10)-en-3α-ol and a heart imaging agent ω-bromoheptadecanoid acid with crown ether as solvents. Compared with other labeling methods used at present, this technique has advantages of speed, simplicity, and higher yield.