PROTEIN-BOUND IODINE BY ALKALINE INCINERATION AND A METHOD FOR PRODUCING A STABLE CERATE COLOR

Abstract

Protein is precipitated with ZnSO4 and NaOH. It is washed, mixed with Na2CO3 and dried and incinerated according to the method of Barker. From this point until the reaction-controlled addition of ceric ion, the I is kept in a reduced state in alkaline medium. Thyroxine standards and KI standards are prepared in 4.0 [image] Na2CO3. The standards are stable and are carried through each step of the analysis. The reaction of the I mono-chloride arsenious sulfato-ceric acid catalysis is controlled by temperature, and by the formation of a stable color with brucine sulfate. The method introduced does not place limits on the number of specimens that constitute a test run.