The determination of vanadium in silicate rocks and minerals with N-benzoyl-o-tolylhydroxylamine

Abstract

In 4 to 8 N hydrochloric acid, N-benzoyl-o-tolylhydroxylamine is an almost specific reagent for vanadium, and can be used in the analysis of rocks and minerals. After removal of silica by evaporation with hydrofluoric acid, the insoluble residue is fused with potassium pyrosulphate and dissolved in dilute sulphuric acid. The violet-coloured complex with the reagent is formed in 6 N hydrochloric acid solution, extracted into carbon tetrachloride and measured at 510 mµ. Fluoride addition prevents interference from titanium, while the use of PTFE and silica apparatus avoids contamination and interference from platinum.