Role of Triiodothyronine-I 131 Purity in T-3 Tests

Abstract

Summary

Using a standard thyrodiagnostic test based on in vitro partitioning of triiodothyronine-I¹³¹ between plasma proteins and erythrocytes of whole blood, results were found to differ depending on the commercial source of labeled triiodothyronine. Chromatographic study showed these preparations to be heterogeneous. Impurities were occasionally present in fresh materials and developed in significant proportions during the accepted usable life of the preparation.