ICP-OES同时测定钒电池级硫酸氧钒中杂质铁铬镍钾钠钙硅铝

Determination of Impurities in Vanadyl Sulfate Used for Vanadium Battery by ICP-OES

建立了采用电感耦合等离子体原子发射光谱法（ICPOES）同时测定钒电池级固体硫酸氧钒中8种关键杂质含量的分析方法，检测范围包括0.001%～0.100%铁铬镍和0.005%～0.100%钾钠钙硅铝。试验考察了样品中高钒基体和硫酸根离子共存体系下基体效应、光谱干扰以及连续背景叠加等影响因素对痕量杂质测定的干扰。研究得到：硫酸根离子对测定无影响，高浓度钒离子的基体效应或连续背景叠加对钾钠产生负干扰，对砷钴铁镍等其余杂质元素产生正干扰的试验结论，并且方法采用基体匹配法和同步背景校正法相结合方式消除高钒基体对杂质测定的影响。通过光谱干扰试验分类归纳总结了钒基体对杂质元素的光谱干扰情况，并且优选了元素分析谱线、背景校正区域以及光谱仪工作条件。分析方法的技术性能达到：背景等效浓度-0.000 3%～0.000 3%，元素检出限0.000 1%～0.000 3%，含量在0.001%～0.007%范围内RSD＜10%，回收率91.0%～110.0%。

The method for simultaneously determining the contents of 8 key impurities in the vanadyl sulfate solid used for vanadium battery by inductively coupled plasma atomic emission spectrometry （ICP-OES） was established respectively with the detection range of 0. 001% - 0. 100% for Fe, Cr, Ni and 0. 005% -0. 100% for K, Na, Ca, Si, A1. The influences of the matrix effects, spectral interferences and continuous background superposition on the measurement of impurities in the samples with coexisting high concentration of vanadium ion and sulfate radical have been studied. It is shown that the sulfate radical in the samples does not affect the measurement, and the matrix effects or continuous background superposition generated by high concentration of vanadium ion, have a negative interference on the content determination for K and Na while a positive inter- ference on the measurement of other impurities such as arsenic （As）, cobalt （Co）, iron （Fe） and nickel （Ni）, etc. Meanwhile, the interference caused by high vanadium matrix was eliminated by eombinative meth- od of matrix matching and synchronous background correction. The interferences of vanadium matrix on the im- purities spectra were also classified and summarized by spectral interference tests, and the analytical spectral lines, background correction regions and working parameters of the spectrometer were optimized. The technical performance indexes of this analysis method are -0. 000 3% -0. 000 3% of background equivalent concentra- tion, 0.000 1% -0.000 3% of element detection limit, RSD 〈10% with 0.001% -0.007% of element con- tent, and 91.0% -110.0% of recovery rate.