董学林，贾正勋，汪慧平，元  艳，方金东

（国土资源部稀土稀有稀散矿产勘查及综合利用重点实验室）

摘  要：多金属矿石样品具有基体复杂的特点，硒、碲元素在自然界的丰度低，若不对其进行有效的前处理，直接分解样品进行测量，会使得测定结果不准确及造成仪器污染。实验先采用硝酸-氢氟酸-高氯酸分解多金属矿石样品，然后在盐酸介质中，以铜盐为接触剂，用次亚磷酸钠将样品溶液中的砷、硒和碲还原成单质后与砷共沉淀，实现了硒和碲与其他元素的分离，消除了基体效应，再采用热硝酸溶解沉淀，采用电感耦合等离子体质谱法进行测定，建立了测定多金属矿石中硒和碲的方法。结果表明，选择铯（¹³³Cs）为内标校正基体效应和漂移，硒、碲元素的校准曲线相关系数可达0.999，检出限分别为0.004、0.003 ng/mL。将实验方法应用于测定多金属矿石标准物质，测定结果与氢化物发生-原子荧光光谱（HG-AFS）基本一致，硒、碲的测定值与认定值吻合，硒和碲的相对标准偏差（RSD，n=7）分别为1.2%~8.5%，1.1%~6.2%。

关键词：共沉淀分离；ICP-MS；硒；碲；多金属矿石

Coprecipitation separation of selenium and tellurium in determination of polymetallic mineral by inductively coupled plasma-mass spectrometry

DONG Xue-lin, JIA Zheng-xun, YUAN Yan,WANG Hui-ping, FANG Jin-dong

 (Hubei Province Geological Experimental Testing Center)

(Key Laboratory of Rare Mineral Experimental Technology, Ministry of Land and Resources, )

Abstract: A method to measure the content of selenium and tellurium in polymetallic ore samples is developed. The method is realized by the combination of ICP-MS and decomposition the sample by the mixture of Nitric Acid, Hydrofluoric Acid, and Perchloric Acid. Selenium and Tellurium are catalyzed by copper salt and reduced as monomer by sodium hypophosphite in the medium of hydrochloric acid. The reductive monomer is concentrated coprecipitation with arsenic and then separated; the separated sample is detected by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). We optimize the types and concentrations of coprecipitation agents and investigate the effect of internal standard elements and concentration on ICP-MS, The results show that the matrix effect and signal drift were corrected with ¹³³Cs as internal standard. The linear correlation coefficients of calibration curve were all 0.999 for Selenium and Tellurium, and the detection limit was 0.004,0.003ng/mL. The proposed method was applied to determination of national geochemical standard reference samples, the results were consistent with those obtained by Hydride Generation-Atomic Fluorescence Spectrometry（HG-AFS）, the results are in good agreement with certified values. The relative standard deviation (RSD，n=7) with precision of Selenium and Tellurium are 1.2%~8.5% and 1.1%~6.2%, respectively.

Keywords：coprecipitation separation；ICP-MS；selenium ；tellurium；polymetallicore