GEL-CHROMATOGRAPHIC ANALYSIS OF TC-99M-LABELED HUMAN-SERUM ALBUMIN PREPARED WITH SN(II) AS THE REDUCTANT

This labeling of human serum albumin (HSA) with **9**9**mTc using Sn(II) as the reductant has been reinvestigated in view of the possibility of formation of Sn-Tc colloids. Preparations of **9**9**mTc-HSA and mixtures of **9**9**mTc-TcO//4** minus with Sn(II)Cl//2 have been analyzed by means of gel chromatography using various gel matrices and eluents. No Sn-Tc colloids could be eluted from samples of **9**9**mTc-HSA preparations. The percentage of labeling was about 90%. A comparative investigation of a number of gel-chromatographic systems for the detailed analysis of **9**9**mTc-HSA has been made. It is found that a long column with Sephadex G-200 gives the best results.