电感耦合等离子体原子发射光谱法测定萤石中11种元素

萤石的主要成分为氟化钙,其中不同元素的存在对其产品质量有不同的影响。传统对萤石成分的测定多采用分光光度法、滴定法和原子吸收光谱法,存在分析流程长,不能多元素同时测定等问题。实验采用高氯酸-硝酸溶解样品,待高氯酸冒烟完毕,用盐酸50%(V/V)溶解盐类,通过选择合适的分析谱线,避免了待测元素间的光谱干扰。研究了溶样方法、钙基体对测定的影响,建立了用电感耦合等离子体原子发射光谱法(ICP-AES)同时测定萤石中铝、硼、钡、铁、镁、锰、钛、锌、钾、钠、磷等11种微量元素的方法。结果表明:通过基体匹配法绘制校准曲线可消除基体效应的影响。各元素的校准曲线线性相关系数均大于0.999;方法中各元素的检出限为0.000 1%～0.003%(质量分数),定量限为0.000 3%~0.010%。按照实验方法测定萤石样品中铝、硼、钡、铁、镁、锰、钛、锌、钾、钠、磷,结果的相对标准偏差(RSD, n=6)为 0.43%～3.4%,按照实验方法测定萤石标准物质中氧化铝、氧化铁、氧化镁、氧化锰、氧化钛、氧化钾、氧化钠、磷,测定结果与认定值基本一致。

Determination of eleven elements in fluorite by inductively coupled plasma atomic emission spectrometry

The main component of fluorite was calcium fluoride. The presence of different elements in fluorite had different influences on the quality of its products. The traditional determination methods of components in fluorite included spectrophotometry, titrimetry and atomic absorption spectrometry. However, these methods had some problems such as long analytical process and inability for simultaneous determination of multiple elements. The sample was dissolved with perchloric acid and nitric acid. After perchloric acid smoking, the salts were dissolved with 50%(V/V) hydrochloric acid.The spectral interference among testing elements was avoided by selecting proper analytical lines. The effect of sample dissolution method and calcium matrix on the determination were studied. A determination method of eleven microelements in fluorite including aluminum, boron, barium, iron, magnesium, manganese, titanium, zinc, potassium, sodium and phosphorus by inductively coupled plasma atomic emission spectrometry (ICP-AES) was established. The results showed that the matrix effect could be eliminated by drawing calibration curve with matrix matching method. The linear correlation coefficients of calibration curves of elements were higher than 0.999. The limits of detection of elements were between 0.000 1% and 0.003% (mass fraction), the limits of quantification were 0.000 3%-0.010% (mass fraction). The contents of aluminum, boron, barium, iron, magnesium, manganese, titanium, zinc, potassium, sodium and phosphorus in fluorite sample were determined according to the experimental method. The relative standard deviation (RSD, n=6) of determination results were between 0.43% and 3.4%. The contents of aluminum oxide, iron oxide, magnesium oxide, manganese oxide, titanium oxide, potassium oxide, sodium oxide and phosphorus in certified reference material of fluorite were determined according to the experimental method, and the results were basically consistent with the certified values.