STUDIES ON IODINATED COMPOUNDS .7. HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC DETERMINATION OF BINDING IODINE IN THYROGLOBULIN AFTER OXYGEN FLASK COMBUSTION AND SOLID-PHASE PRECONCENTRATION

A sensitive method was investigated for the determination of binding i odine in thyroglobulin (TG). The method was based on the solid-phase p reconcentration of iodide (I-) in the absorbing solution prepared by t he oxygen flask combustion of TG. The optimum procedures were discusse d for the preconcentration. The absorbing solution was passed through a cation-exchange column (AG-50), followed by an anion-exchange column (Bond Elut PSA). Iodide concentrated on the Bond Elut PSA was eluted with ammonia water and treated with the AG-50. An aliquot of the conce ntrated sample was subjected to reversed-phase HPLC with a UV detector for the determination of I-. The method was applied successfully to t he determination of binding iodine in trace amounts of TG.