Oxygen Flask Decomposition of Blood Serum: Application To PBI Determination

Abstract

Abstract A novel approach is presented for converting organically bound iodide of blood serum into the corresponding inorganic state for protein-bound iodine measurement. The technic consists of oven-drying 1 ml resin-treated serum in a collodion-impregnated filter paper holder, burning the dried sample in a Schoniger oxygen flask, and absorbing the decomposition products in a suitable absorbing medium. The extract is then submitted to an automated, analytic, photometric assay method based on the iodide-iodine catalysis of the cerium-arsenic reaction. The procedure eliminates the possibility of cross-contamination because each sample is handled in a separate, sealed reaction flask. The method yields reproducible results which compare favorably with PBI technics currently in existence. The investigation represents the first known instance of the Schoniger process being applied to iodine determinations in the 1-10 [Lg/100 ml range.