电感耦合等离子体原子发射光谱法测定高硫铜磁铁矿中硫

铜磁铁矿作为冶炼铜和铁的重要原料,有害元素硫含量较高。试样经逆王水消解、氢氟酸挥硅和高氯酸进一步氧化后,在硝酸体系中,选择S 182.034nm为分析谱线,使用铁基体匹配的标准溶液系列绘制校准曲线消除基体效应的影响,使用电感耦合等离子体原子发射光谱法(ICP-AES)测定高硫铜磁铁矿中硫。硫质量浓度为0.10~150μg/mL时与其发射光谱强度呈良好的线性关系,线性相关系数为0.9998;方法检出限为0.0135%。实验方法用于测定5个含量水平高硫铜磁铁矿样品中硫,测定结果的相对标准偏差(RSD,n=11)为2.1%~3.7%,与高频燃烧红外吸收法的测定结果没有显著性差异。方法的重复性标准差为S_r=0.0135x+0.0143,重复性限为r=0.0379x+0.0396,再现性标准差为S_R=0.0232x+0.0137,再现性限为R=0.0653x+0.0383。

Determination of sulfur in high-sulfur copper magnetite by inductively coupled plasma atomic emission spectrometry

Copper magnetite was an important raw material for the smelting of copper and iron. The content of harmful element in copper magnetite, i.e., sulfur, was relatively high. The sample was digested by reverse aqua regia. After volatilizing silicon by hydrofluoric acid and further oxidization by perchloric acid, the content of sulfur in high-sulfur copper magnetite was determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) in nitric acid system with S 182.034nm as the analytical line. The calibration curve was prepared with standard solution series which were matched with iron matrix to eliminate the influence of matrix effect. When the mass concentration of sulfur was in range of 0.10-150μg/mL, it showed good linear relationship with the corresponding emission intensity. The linear correlation coefficient was 0.9998. The detection limit of method was 0.0135%. The proposed method was applied for the determination of sulfur in five content levels of high-sulfur copper magnetite samples. The relative standard deviations (RSD, n=11) of the determination results were between 2.1% and 3.7%, which had no significant difference with the results obtained by high frequency combustion infrared absorption method. The standard deviation of repeatability of method was S_r=0.0135x+0.0143. The repeatability limit was r=0.0379x+0.0396. The standard deviation of reproducibility was S_R=0.0232x+0.0137. The reproducibility limit was R=0.0653x+0.0383.