Preparation of 35S-Labeled Sulfite by Pyrolyzation of Copper(II) Sulfate

A study was made on the preparation of 35S-labeled sulfite by the pyrolyzation of labeled Cu(II) sulfate. Factors such as the amount of carrier sulfate and the NaOH concentration of the absorbing solutions, which were thought to affect the yield and radiochemical purity of the final products, were examined together with the chemical stability of the sodium sulfite (35S) thus obtained in aqueous solutions. The method has proved to be useful for practical preparation of 35S-labeled sulfite. With Cu(II) sulfate carrier ranging 20∼176 mg, more than 80% of 35S can be recovered as sulfite. Carrier-free sulfite (35S) can also be obtained by merely replacing the Cu(II) sulfate carrier with Cu(II) chloride and carrier-free H2 35SO4.