ICP-AES法测定湿法磷酸中铝镁铁

Determination of aluminum,magnesium and iron in wet-process phosphoric acid by ICP-AES

建立了电感耦合等离子体—原子发射光谱法(ICP-AES)快速、准确并同时测定湿法磷酸中的铝、镁和铁,选定灵敏度较高的特征谱线作为分析线,优化仪器工作参数,无需使用磷酸配制标准工作溶液即可消除基体效应对测定结果的影响。在光谱仪处于最佳分析条件下,选定波长分别为396.156 nm、279.077 nm、238.204 nm的特征谱线作为本方法中元素铝、镁和铁的分析线。利用方法同时测定湿法磷酸中铝、镁和铁金属元素含量,检出限分别为0.0013μg/mL、0.0022μg/mL、0.0054μg/mL,铝、镁和铁测定结果的相对标准偏差(RSD)分别为1.5~6.5%、1.8~5.3%、2.5~8.0%,各项加标回收率为96.9%~106.2%、92.5%~104.0%、97.0%~105.5%。同时与标准加入法进行对比实验,分析结果基本吻合,铝、镁和铁的相对偏差(SD)分别≤3.85%、2.84%、2.63%,验证方法的准确性,能够满足科研及企业日常生产对湿法磷酸中铝、镁和铁一次性测定的需要。

In this study,we developed a rapid and accurate method to simultaneously detect aluminum,magnesium and iron in wet-process phosphoric acid by inductively coupled plasma-atomic emission spectrometry（ ICPAES）. We selected spectral lines with higher sensitivity as the analytical lines,optimized the instrument parameters,and developed a method to eliminate the influence of the matrix effect on the determination results without using phosphoric acid to prepare the standard solution. Spectral lines with wavelengths of 396. 156 nm,279. 077 nm,238. 204 nm were selected as the analytical lines for aluminum,magnesium and iron,respectively. The detection limits of aluminum,magnesium and iron were 0. 0013 μg/mL,0. 0022 μg/mL,and 0. 0054 μg/mL,respectively. The RSD of aluminum,magnesium and iron were 1. 5% to 6. 5%,1. 8% to 5. 3%,and 2. 5% to 8. 0%,respectively. The recovery rates of aluminum,magnesium and iron were 96. 9% to 106. 2%,92. 5% to 104. 0%,and97. 0% to 105. 5%,respectively. The results of this new method were basically consistent with the results of the standard addition method,with the SD less than 3. 85%,2. 84% and 2. 63%,respectively. The accuracy of this new method was verified,and it was proved that this method could meet the demands of scientific research and daily production.