SPECTROPHOTOMETRIC DETERMINATION OF VANAD IUM IN SHALE OILS

A selective method has been developed for de determination of vanadium in petroleum and in shale oils. In a typical procedure, the appropiat e sample was ashed and analysed by spectrophotometry. The measurements were based on the development of yellow coloured solution by the reac tion of vanadium(V) and 2,7-Fluorenediamine in phosphoric acid medium. The yellow species obeys Beer's Law at 435 nm from 0.10 up to 1.63 p. p.m. of vanadium with a molar absorptivity of 2.8x10(4) 1.mol-1.cm-1. The interferences of MnO4- and Cr2O72- were suppressed by masking with arsenium(III) solution.