微波消解-电感耦合等离子体原子发射光谱法测定富钛料中14种杂质元素

Determination of fourteen impurity elements in titanium-rich material by microwave digestion-inductively coupled plasma atomic emission spectrometry

以HF、HNO3和HCl的混酸(VHF∶VHNO3∶VHCl=1∶6∶3)为消解试剂,采取斜坡升温方式,在优化的消解程序下对样品进行微波消解,消解液以水定容后采用电感耦合等离子体原子发射光谱法(ICP-AES)测定Si、Al、Mn、P、Cu、Co、Cr、Ni、V、As、Cd、Pb、Ca、Mg等14种杂质元素含量。考察了样品的最佳消解条件和光谱干扰情况。结果表明,样品采用以5min升温至130℃并保持3min,再以5min升温至200℃并保持10min的消解程序消解的效果最好;选择合适的光谱线作为被测元素的分析线并采用基体匹配及同步背景校正法可以消除钛基体影响和谱线的重叠干扰。方法的检出限为5μg/L(Mg)～60μg/L(Si),背景等效浓度为4μg/L(Mg)～55μg/L(Si),用于测定富钛料中上述元素,相对标准偏差(RSD,n=8)≤6.5%,加标回收率在95%～108%之间。

The samples were digested by microwave under optimized digestion procedure with ramped temperature program using mixed acid （VHF = VHNO3： VHCI=1： 6 ： 3） as digestion reagent. After the digestion solution was diluted to the mark with water, the content of fourteen impurities including Si, AL, Mn, P, Cu, Co, Cr, Ni, V, As, Cd, Pb, Ca and Mg was determined by inductively coupled plasma atomic emission spectrometry （ICP-AES）. The optimal digestion conditions and spectral inter- ference for sample was investigated. The results showed that the optimal digestion procedure was as follows increasing the temperature to 130 ℃ within 5 min and keeping for 3 min, and then increasing the temperature to 200 ℃ within 5 min and keeping for 10 rain. The titanium matrix effect and spec- tral overlapping interference were eliminated by selecting the proper spectral lines as the analytical lines for testing elements, matrix matching and synchronous background correction method. The de- tection limit of method was 5 μg/L （Mg）-60μg/L （Si）. The background equivalent concentration was 4 μg/L （Mg）-55 μg/L （Si）. The proposed method was applied to the determination of fourteen impu- rity elements in titanium-rich material. The relative standard deviation （RSD,n= 8） was not larger than 6.5 %, and the recoveries of standard addition were between 95 % and 108%.