微波消解-双浊点萃取ICP-MS测定地球化学样品中的痕量铂钯钌铑  

Determination of Pt,Pd,Ru,Rh in Geochemical Samples by ICP-MS with Microwave Digestion and Dual-cloud Point Extraction

作　　者：沈宇[1,2] 张尼[1,2] 高小红[1] 李展[1] 李日升[1] 郑建斌[2] 

机构地区：[1]西安西北有色地质研究院有限公司,陕西西安710054 [2]西北大学分析科学研究所陕西省电分析化学重点实验室,陕西西安710069

出　　处：《岩矿测试》2016年第3期259-264,共6页Rock and Mineral Analysis

基　　金：陕西省科技计划项目(2015KJXX-81);陕西省工业科技攻关项目(2015GY54)

摘　　要：传统浊点萃取技术是将待测元素富集在黏稠的表面活性剂相中,溶液的黏度会对等离子体检测信号产生影响,通常使用甲醇作为稀释剂降低有机相黏度,有机成分也对等离子体的稳定性产生影响,同时有机物在进样管路上的吸附还会提高待测元素的记忆效应,因而限制了ICP-MS在浊点萃取中的应用。本文建立了双浊点萃取技术ICP-MS测定地球化学样品中铂钯钌铑的分析方法。样品用微波消解处理后,以DDTP为螯合剂,Triton X-114为表面活性剂,对消解溶液第一次浊点萃取,再在有机相中加入硝酸,通过加热完成第二次浊点萃取,使铂钯钌铑由有机相进入水相,铂钯钌铑的富集因子分别为45、33、18和35,高于单次浊点萃取的富集因子,ICP-MS检出限分别为0.05、0.02、0.10和0.03μg/L。本方法通过两次浊点萃取过程实现了基体复杂的地球化学样品中痕量铂族元素的同时富集,提高了ICP-MS的稳定性。Traditional cloud point extraction methods commonly enrich elements in the viscous surfactant.However,the viscosity of the solution will adversely affect the detection signal of the plasma. Harmful agents such as methanol are usually adopted as a thinner to reduce the viscosity of the organic phase,but the organic component affects the stability of the plasma,and organic absorption on the injection tube will enhance elemental memory effect. These disadvantages limit the widespread application of Inductively Coupled Plasma-Mass Spectrometry( ICP-MS) in cloud point extraction. A method to determine Pt,Pd,Ru,Rh in geochemical samples by ICP-MS based dual-cloud point extraction has been established,and is reported in this paper. After the microwave digestion procedure,first cloud point extraction is performed on the sample solution using DDTP as the sequestrant and Triton X-114 as the surfactant. HNO3 is added into the organic phase,and second cloud point extraction is performed by heating so that Pt,Pd,Ru,Rh enter the water phase from the organic phase.Enrichment factors are 45,33,18,35,and detection limits are 0. 05,0. 02,0. 10 and 0. 03 μg / L for Pt,Pd,Ru and Rh,respectively. The proposed method succeeds in the simultaneous enrichment of trace platinum group elements in complex matrix geochemical samples,improving the stability of the ICP-MS measurement.

关 键 词：地球化学样品 铂族元素 双浊点萃取 有机相 水相 电感耦合等离子体质谱法 

分 类 号：O657.63[理学—分析化学] O614.82[理学—化学]