ICP-AES法测定工业红矾钠中的杂质元素

ICP-AES Determination of Impurity Elements in Industrial Na_2Cr_2O_7

红矾钠溶解后、分取一定体积加入高氯酸冒烟,再加入盐酸使Cr元素以氯化铬酰(CrO_2Cl_2)气体形式挥发除去,电感耦合等离子体原子发射光谱法测定钙、镁、铝、锰、铁。该方法避免了铬基体匹配及对杂质元素测定的干扰,结果表明:钙、镁、铝、锰和铁5种元素校准曲线的相关系数均大于0.9990,方法的检出限在0.003～0.027μg/m L之间,相对标准偏差为1.32%～2.31%,加标回收率达到96%～104%,并与火焰原子吸收光谱法的结果进行比对,测定结果相一致。

The sample of Industrial NazCr2O7 was dissolved with deionized water,and constant volume,the solution was divided and HClO4 were added for smoking, then adding hydrochloric acid, Cr elements is removed in the form of chromyl chloride gas（ CrO2Cl2） ,Ca315.887 nm, Mg285.213 nm, Al167.076 nm, Mn293.930 nm and Fe259.940 nm were selected as analytical lines,the proper background deduction position was set. The influence of Na matrix effect was eliminated by preparing calibration curves using Na matrix matching method.The content of calcium, magnesium, aluminum, manganese and iron were simultaneously determined by inductively coupled plasma atomic emission spectrometry, the determination method of magnesium, aluminum, manganese and iron in Industrial Na2Cr2O7 was established.This method avoided Cr matrix matching and interferencing for the determination of impurity elements. The results showed that the correlation coefficients of calibration curves of five elements about calcium, magnesium, aluminum, manganese and iron were all higher than 0.9990. The detection limits of method were between 0.003 μg/mL and 0.027 μg/mL. The relative standard deviations （RSD） were between 1.32% and 2.31% ,Values of recoveries of method were between 96%- 104% ,The results were consistent with those obtained by flame atomic absorption spectrometry（FAAS）.