Radioiodine Compounds of Human Urine after 131I Therapy

The method cannot be used to measure the amount of each 13II-labelled compound quantitatively because of the losses of organic radioiodine (see Table 1) at each step. Quantitative analyses of the organic radioiodine fraction is probably best performed by removal of iodide on a column of silver chloride followed by butanol extraction and paper chromatography of the remaining organic iodine compounds. The method described here is primarily useful for concentrating the organic iodine compounds for qualitative study. Its use is limited to urines of relatively high radioactivity, at least 0 003 Kc of organic radioiodine/ml., and it is therefore not applicable to study of organic radioiodine compounds of urine after tracer doses of 131I. As the method is not quantitative, the relative amount of each component does not give any insight into the turnover of iodine in vivo, and may in fact reflect merely the efficiency of the method, some compounds being more completely recovered than others.