浊点萃取-电感耦合等离子体质谱法测定环境样品中的痕量铂钯  

Determination of trace platinum and palladium in environmental samples by cloud point extraction coupled with inductively coupled plasma-mass spectrometry

作　　者：张欣[1] 刘崴[1] 李冰[1] 胡俊栋[1] 

机构地区：[1]国家地质实验测试中心,北京100037

出　　处：《分析试验室》2012年第11期63-66,共4页Chinese Journal of Analysis Laboratory

基　　金：国土资源部公益性行业科研专项经费(200911043-27)资助

摘　　要：建立了浊点萃取-电感耦合等离子体质谱法测定环境样品中痕量铂钯的新方法。以2-巯基苯并噻唑(2-MBT)为络合剂,在1 mol/L的HCl介质中,用非离子型表面活性剂聚乙二醇辛基苯基醚(Triton X-100)浊点萃取样品溶液中痕量铂钯。考察了溶液酸度、2-MBT用量、表面活性剂用量、萃取时间、平衡温度、SnCl2加入量、干扰离子等条件对浊点萃取效率的影响。在优化条件下,该方法对铂钯的萃取率在95%以上,方法检出限Pt为0.22 ng/g,Pd为0.17 ng/g。对水体、土壤及街尘等样品中的铂钯含量进行了测定。Accurate determination of precious metals at trace levels in environmental matrices is still a difficult task because of their complex components and the possible interferences during analyzing. Cloud point extraction （CPE） is a new kind of preconcentration and separation technology which has many prominent virtues such as completely phase separation, easy to be operated, high enrichment efficiency and less harmful for environment and operators. It has been successfully used in the determination of lead, zinc, cobalt, copper and many other metals. But the study about precious metals in environmental matrices using CPE was comparatively few. So in this paper a new method for the determination of trace amounts of platinum and palladium in environmental samples using CPE coupled with ICP-MS is described. Trace amounts of Pt and Pd were extracted from the sample solutions in the form of coordination complex with 2-mercaptobenzothiazole （2-MBT） in 1 moL/L HC1 medium,using a non-ionic surfactant Triton X-100. The main parameters affecting extraction and determination were evaluated in detail, such as the solution acidity, the amount of 2-MBT, the concentration of Triton X-100 and SnCl2, the extraction temperature and time, as well as the interferences. Under optimized conditions, the recoveries of Pt and Pd were all above 95%. The detection limits obtained for Pt and Pd were 0. 22 ng/g and 0. 17 ng/g, respectively. CPE has an effective alleviation of interfering ions and a relatively sensitivity for separating the elements of Pt and Pd from large amount of co-existing ions which could influence the subsequent determination by ICP-MS. The method was successfully applied to the analysis of trace amounts of Pt and Pd in water, road dust and soil samples. The results showed that this method is reliable and can meet the most request of Pt and Pd determination in many environmental samples.

关 键 词：浊点萃取 环境样品 电感耦合等离子体质谱法 铂 钯 

分 类 号：O657.63[理学—分析化学]