Abstract
The conditions for the determination of tungsten in iron and steel have been studied by the use of perchloric acid. Tungsten can be precipitated quantitatively with a single fuming of perchloric acid by the following treatment: the sample is dissolved in aqua regia and evaporated to white fume after addition of 50 c. c. of perchloric acid; after cooling, dilute hydrochloric acid is added and its total volume is made up to 150c. c. so as to adjust the concentration of hydrochlioric acid between 1_??_1.5 N. The solution issued is Warmed at 70_??_80° for an hour and then filtered. Applying this method also to the rapid determination, we have found that tungsten would be determined in about 20 minutes.
