全谱电弧发射光谱法测定五氧化二铌中18种杂质元素

基于Nb₂O₅样品溶解困难、测定杂质元素多的特点,研究了全谱电弧发射光谱仪测定Nb₂O₅样品中18种杂质元素的方法。试验了光谱缓冲剂、电极形状、样品装填方式、分析谱线、信号采集时间等对测定效果的影响。结果表明,石墨粉、氟化钠、氧化镓以94∶5∶1的质量比混合作为光谱缓冲剂;采用孔径4mm、深7mm的孔型石墨电极作为下电极;样品装满电极后下压2mm,并滴加蔗糖溶液;各元素最佳分析谱线在各自特征蒸发时间内采集信号强度,测定结果最优。在选定的工作条件下,各元素检出限均小于1.5μg/g,样品加标回收率在86%~118%之间;对合成校准样品进行测定,测定值与理论值基本一致,各元素10次测定结果的相对标准偏差(RSD)均小于10%。

Determination of eighteen impurity elements in niobium pentoxide by full spectrum arc emission spectrometry

According to the characteristic that the Nb₂O₅ sample is hardly dissolved and there are many impurity elements, the determination method of 18 impurity elements in niobium pentoxide sample using full spectrum arc emission spectrometer was studied. The influence of spectral buffer, electrode shape, sample loading method, analytical line and signal acquisition time on the determination was investigated. The results showed that the mixture of graphite powder, sodium fluoride and gallium oxide in mass ratio of 94∶5∶1 was used as the spectral buffer. The pass graphite electrode with pore size of 4mm and depth of 7mm was selected as the bottom electrode. After filling the electrode with sample, it was pressed downwards for 2mm and the sucrose solution was added. When the signal intensity was collected for each optimal analytical line of elements within corresponding characteristic evaporation time, the determination results were best. Under the selected working conditions, the limit of detection were all lower than 1.5μg/g. The recoveries were between 86% and 118%. The synthetic calibration sample was determined and the found results were basically consistent with the theoretical values. The relative standard deviations (RSD, n=10) of determination results for elements were all less than 10%.