电感耦合等离子体原子发射光谱法测定工业红矾钠中钙镁铝锰铁

准确测定工业红矾钠中杂质元素含量,对于判定工业红矾钠生产工艺及产品用途合格与否具有重要意义。在红矾钠溶液中加入高氯酸并加热冒烟,滴加盐酸使铬以氯化铬酰(CrO₂Cl₂)气体形式挥发除去,采用钠基体匹配法绘制校准曲线可消除基体效应的影响,在选定的仪器工作条件下,选择Ca 315.887nm、Mg 285.213nm、Al 167.076nm、Mn 293.930nm、Fe 259.940nm为分析谱线,使用电感耦合等离子体原子发射光谱法(ICP-AES)测定钙、镁、铝、锰、铁,从而建立了测定工业红矾钠中钙、镁、铝、锰、铁的方法。钙、镁、铝、锰、铁的校准曲线相关系数均大于0.999;方法中各元素的检出限为0.003~0.027μg/mL。按照实验方法测定工业红矾钠样品中钙、镁、铝、锰、铁,加标回收率为96%~104%;结果的相对标准偏差(RSD,n=8)为1.3%~2.3%,并与火焰原子吸收光谱法(FAAS)测定结果相吻合。

Determination of calcium,magnesium, aluminum,manganese and iron in industrial sodium bichromate by inductively coupled plasma atomic emission spectrometry

The accurate determination of impurity elements in industrial sodium dichromate is great significance to judge the production process and application quality of industrial sodium dichromate. The perchloric acid was added into sodium dichromate solution and heated to fuming. Then hydrochloric acid was added dropwise to remove chromium in the form of chromyl chloride gas (CrO₂Cl₂). The influence of matrix effect was eliminated by preparing the calibration curves with Na matrix matching method. Under the selected working conditions of instrument, Ca 315.887nm, Mg 285.213nm, Al 167.076nm, Mn 293.930nm and Fe 259.940nm were selected as the analytical lines. The content of Ca, Mg, Al, Mn and Fe in industrial sodium dichromate was determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). Thus the determination method of Ca, Mg, Al, Mn and Fe in industrial sodium dichromate was established. The correlation coefficients of calibration curves for Ca, Mg, Al, Mn and Fe were all higher than 0.999. The detection limits of elements were between 0.003μg/mL and 0.027μg/mL. Calcium, magnesium, aluminum, manganese and iron in industrial sodium bichromate were determined according to the experimental method. The spiked recoveries were between 96% and 104%. The relative standard deviations (RSD, n=8) of determination results were between 1.3% and 2.3%. The found results were consistent with those obtained by flame atomic absorption spectrometry (FAAS).