Study of Inhibition of the Ceric-Arsenite Reaction and Application to Analysis of Protein-Bound Iodine

Clinical Chemistry

“…A study by Blackburn and Power (27) of the diagnostic accuracies of protein-bound iodine (PBI), basal metabolic rate, and uptake of radio-iodine determinations of serum, indicated that protein-bound iodine (PBI) was the most valuable single test in the clinical evaluation of thyroid function. Grossman and Grossman (85) and several others have suggested the addition of brucine for stabilizing the cerate color at a selected time interval, and mercuric acetate was proposed for the same purpose by Meyer and coworkers (139). The best stabilizing technique was discovered by Fischl (69) who employed brucine acetate to inhibit the ceric-arsenious system and greatly enhanced and stabilized the color by heating on the water bath for 5 minutes The color was enhanced sufficiently to permit protein-bound iodine determinations on 0.1 ml.…”

The Nature, Determination, and Clinical Importance of Blood Iodine: A Review

“…With satisfactory instrumentation, a theoretical straight line calibration curve can be obtained (Acland, 1957) in the presence of chloride and sulphate, the former of which enhances the catalytic effect of iodide (Barker, 1948) while the latter retards it (Klein, 1954). Several workers (e.g., Grossmann and Grossmann, 1955;Meyer, Dickenman, White, and Zak, 1955;Fischl, 1956) have reported methods of poisoning the ceric sulphate-arsenious acid reaction, so that photometer readings may be made at any time after the reaction has stopped. This technique is claimed to be more accurate than that whereby readings are made at a fixed time after starting the reaction, while the optical density is still decreasing.…”