微波消解-电感耦合等离子体原子发射光谱法测定钒钛磁铁矿中锆铌钒铬

提出微波消解与电感耦合等离子体原子发射光谱法测定相结合的方法测定了钒钛磁铁矿中锆、铌、钒和铬。方法以 HF与HNO₃为消解试剂,用高压密闭微波消解技术消解样品,因此钒钛磁铁矿中基体以及共存杂质氧化锆、氧化铌、氧化铬等难以被酸消解的组分可得到很好的溶解。在氢氟酸介质中测定避免了高浓度钛基体和铌、锆等待测元素在低酸度介质中容易水解所导致的影响。通过筛选待测元素分析谱线以及综合运用基体匹配与同步背景校正法消除了光谱干扰和基体效应的影响。背景等效浓度值从0.000 2%(Cr)至0.000 8%(Nb),测定下限为0.001 7%(V)～0.002 9%(Nb)。方法用于钒钛磁铁矿中锆、铌、钒和铬的测定,测定结果与火焰原子吸收光谱法及电感耦合等离子体质谱法相符,相对标准偏差(n=8)均不大于4.7%。

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%.