Determination of zirconium,niobium,vanadium and chromium in vanadium titano-magnetite ore by microwave digestion inductively coupled plasma atomic emission spectrometry

A method was proposed to combine microwave digestion and inductively coupled plasma atomic emission spectrometry for determination of zirconium,niobium,vanadium and chromium in vanadium titano-magnetite ore.With HF and HNO3 as digestion reagents,high-pressure sealed microwave digestion technique was used to digest the sample,so the components were difficult to digest with acids such as the vanadium titano-magnetite matrix and the coexisting impurities of zirconium oxide,niobium oxide and chromium oxide could be dissolved.Determination in the hydrofluoric acid medium avoided the interference caused by high-concentration titanium matrix and niobium and zirconium analytes which could be hydrolyzed easily in low-acidity media.The influence of spectral interference and matrix effects was eliminated by the selection of analytical lines for the analyte elements and the comprehensive use of matrix matching and synchronous background correction.Background equivalent concentration was from 0.000 2%(Cr)to 0.000 8%(Nb),and the quantitative limit of determination was 0.001 7%(V)-0.002 9%(Nb).The method was applied to the determination of zirconium,niobium,vanadium and chromium in vanadium titano-magnetite ore and the results were consistent with those obtained by flame atomic absorption spectrometry and inductively coupled plasma mass spectrometry, with relative standard deviation(n=8)no more than 4.7%.