The photometric determination of tungsten

Thiocyanate Spectrophotometric Determination of Molybdenum and Tungsten

“…The literature on the development of tungsten-thiocyanate methods has been compiled in previous works (6)(7)(8). Gentry and Sherrington (8) made the reduction of tungsten(VI) to tungsten(V) prior to the addition of the thiocyanate and reported improved color stability.…”

“…The literature on the development of tungsten-thiocyanate methods has been compiled in previous works (6)(7)(8). Gentry and Sherrington (8) made the reduction of tungsten(VI) to tungsten(V) prior to the addition of the thiocyanate and reported improved color stability. Freund, Wright, and Brookshier (6) have studied the effect of the chloride ion and hydrogen ion concentration on the reduction of tungsten with stannous chloride.…”

A field method for the determination of tungsten in soils

“…Still other changes have been made in attempts to shorten the method and/or obtain better precision (Geld and Carroll, 1949;Gentry and Sherrington, 1948). Extraction of the tungsten thiocyanate complex ion with an immiscible solvent results in increased sensitivity (Sandell, 1950), and heating the reaction mixture decreases the time required to form the complex ion (Poluektov, 1941).…”