The automated photometric determination of vanadium in geological samples with 4-(2-pyridylazo) resorcinol

Vanadium is determined in geological samples utilising the red complex formed between V⁵⁺ and 4-(2-pyridylazo) resorcinol. The determination is performed with the Technicon Auto Analyzer. The method has been applied to the determination of the element in standard rock and mineral samples after fusion with sodium carbonate and magnesium oxide. Using this sensitive method, it is possible to determine as little as 1 p.p.m. vanadium in a 200-mg sample of silicate rock or mineral.