Standard Reference Materials: Comparison of Redox Standards

Abstract : The methods described in this publication are those that have been used at the National Bureau of Standards for the comparison of the current oxidimetric standard reference materials with each other and for the determination of the effective purity of these standard reference materials. The methods, which are modifications of well-established and previously published methods, were selected or designed for their accuracy and dependability. An accurate method was devised for the determination of the effective purity of the arsenic trioxide standard SRM 83c by adding solid iodine and determining the excess iodine photometrically.