Abstract

Although the measurement of iodine concentration in the blood plasma is of considerable interest in connection with the use of iodine-containing drugs, the best methods now available require nearly 40 cc. of blood for duplicate analyses of blood at physiological concentrations. This fact limits the use of such methods in man, and prohibits them in small animals. The present communication describes a micro-analytical technique which will yield duplicate analyses from 2 cc. of blood plasma or serum. The method involves the catalytic effect of iodide upon the reduction of ceric ion. The technique is colorimetric and is adaptable to standard photoelectric colorimeters such as are available in many laboratories at the present time.