Nicotinamidoxime as an analytical reagent

Summary Uranium (VI) has been found to give a yellow colour with nicotinamidoxime in alkaline medium which is highly satisfactory for the spectrophotometric estimation of the metal. The optimumph for development of the colour is 10.9–11.5 in presence of a large excess of the reagent, at 10–40C. The colour intensity is measured at 400 m. Sensitivity is 0.045 g uranium per cm², with a visual identification limit of 5 g uranium per ml. Beer's law is obeyed in the range of 5–40 ppm of the metal with an optimum range of 8–40 ppm. The colour is stable for at least one hour. All the common anions are without effect, excepting however, phosphate, carbonate, and cyanide which are tolerated only in traces. Use of tartrate or EDTA helps to mask effectively all the interfering cations excepting copper, iron and vanadium.