电感耦合等离子体发射光谱法测定含重晶石的银铅矿中的铅

测定银铅矿中的铅，常规分解方法是采用酸溶法（王水和四酸）处理样品。当银铅矿中重晶石含量为40%~80%时，酸溶法不能完全分解样品，造成铅的测定结果偏低；且样品中大量硫酸钡的存在易与铅生成铅钡复盐沉淀而影响铅的准确测定。本文采用过氧化钠碱熔法分解样品，在试液中加入氯化钡，应用电感耦合等离子体发射光谱法测定重晶石含量高的银铅矿中铅的含量，通过优化取样量与稀释倍数等参数，配合高盐雾化器的使用有效避免了基体干扰。方法检出限为0.013%，相对标准偏差（RSD）为1.1%~1.6%，回收率为97.9%~102.9%，标准样品的测定结果可靠。本法采用过氧化钠碱熔，可完全彻底地分解样品；氯化钡的加入使重晶石含量高的银铅矿样品中硫酸钡对铅的干扰被消除，而对不含重晶石的铅矿样品中铅的测定无影响。本法解决了银铅矿与高含量重晶石共生时样品难分解的问题，同时解决了硫酸钡干扰测定铅的问题。

Determination of Lead in Argentalium Ores Containing Barite by Inductively Coupled Plasma-Atomic Emission Spectrometry

Acid digestion (aqua regia, tetracid), as a conventional method, is usually used for dissolving Ag-Pb deposit to detect Pb. However, samples containing 40%-80% of barite are difficult to dissolve completely, possibly causing low results for Pb. Additionally, determination results can also be affected due to the formation of double salt precipitation from BaSO₄ reacting with Pb. In this paper, a novel method for dissolving Ag-Pb ores by Na₂O₂ and determination of Pb by Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) combining with high salt nebulizer was proposed. Experimental conditions such as sample volume and multiple dilutions were optimized. The detection limit was 0.013%, RSD was 1.1%-1.6% and recovery was 97.9%-102.9%. The samples were decomposed completely by alkali fusion with Na₂O₂. The addition of BaCl₂ can eliminate the influence of sulfate on Pb for barite-bearing sample. However, there is no effect for non-barium-barite samples. This method solves the problems of both difficult and complete decomposing for Ag-Pb ores with high content barite and the influence of BaSO₄ in the quantification of Pb.