电感耦合等离子体发射光谱法测定富镁铁橄榄岩类矿石中铜镍铁和氧化镁

样品经氢氟酸-盐酸-硝酸-高氯酸混合酸一次加入冷浸直接溶解,在5%(体积分数)的盐酸介质中,用电感耦合等离子体发射光谱法测定富镁铁橄榄岩类矿石中的铜、镍、铁、氧化镁,克服了传统分析方法操作繁琐、周期长、成本高,而过程难以控制等缺点。方法检出限为铜2.0μg/g,镍3.0μg/g,铁10μg/g,氧化镁20μg/g;精密度(RSD,n=12)为0.8%～4.1%。经国家一级标准物质分析验证,测定值与标准值吻合,结果准确可靠。对于富镁铁岩类矿石中含量较高的硫化物的测定,采用一次加混合酸冷浸除硫后,再加热分解样品,结果令人满意;其中含量较高的铁和氧化镁,采用分取稀释测定,减小基体干扰。建立的方法样品处理程序简单快速,线性范围宽,分析重现性好,适用于地质部门批量样品的分析。

Determination of Cu, Ni, Fe and MgO in Rich Fe-Mg Peridotite Rocks by Inductively Coupled Plasma-Atomic Emission Spectrometry

Samples were digested with mixed acids of HF-HCl-HNO3-HClO4,in 5% HCl solution.Peridotite enriched Cu,Ni,Fe,MgO were directly determined by inductively coupled plasma-atomic emission spectrometry(ICP-AES).The method overcomes the shortfalls of traditional methods such as: long-term,complicated chemical procedure and the chemical procedure being difficult to control.The detection limits of the method are 2.0 μg/g for Cu,3.0 μg/g for Ni,10 μg/g for Fe and 20 μg/g for MgO.The reliability of the method has been tested by determination of those elements in national standard references and the results are in good agreement with certified values with precisions of 0.8%-4.1% RSD(n=12).Satisfactory results were obtained for the ores present in Fe-Mg enriched rocks with higher sulfides composition by using the technique of cold soaking in mixed acids to remove sulphur and then digestion with heating.The sample solution was diluted before measurement to decrease matrix effect for the sample with high concentrations of Fe and MgO.This method exhibits simplicity,rapidity,good reproducibility and wide linearity.It is suitable for a multi-elemental determination of dissolved minerals.