SPECTROPHOTOMETRIC DETERMINATION OF VANADIUM IN GLASS AND CERAMICS AFTER EXTRACTION OF THE VANADIUM SALICYLHYDROXAMIC ACID COMPLEX ON POLYURETHANE FOAM

A simple spectrophotometric method was developed for the determination of traces of vanadium present in glass and ceramic raw materials. The method involves the formation of a vanadium-salicylhydroxamic acid complex in 1 M HF-H2SO4 medium, followed by extraction on polyether-based polyurethane foam and elution of the complex with acidified acetone (9.5 ml of acetone + 0.5 ml of 1 M HCl) for spectrophotometric measurement at 520 nm. The method obeys Beer's law from 0.5 to 10-mu-g V ml-1. The molar absorptivity was calculated to be 6.9 x 10(3) mol 1(-1) cm-1 at 520 nm. Interferences from other metals, viz., Fe, Co, Mo, Zr, Hf and Ti, were eliminated by using HF medium. The method was applied to several glass and ceramic samples.