同位素稀释电感耦合等离子体质谱法分析降尘中铂族元素

Determination of Platinum Group Elements in Fall Dust by Isotope Dilution Inductively Coupled Plasma Mass Spectrometry

选取195Pt和108Pd为待测同位素,196Pt和105Pd为富集同位素,同位素稀释电感耦合等离子质谱法(ID-ICP-MS)测定降尘样品中195Pt/196Pt和108Pd/105Pd比值,分析样品中Pt和Pd含量。利用Dowex AG50W-8阳离子交换和N-苯甲酰-N苯基羟胺(BPHA)溶剂萃取法消除干扰。研究了影响同位素比值准确测定的因素,校正Pt和Pd质量歧视效应,确定了最佳同位素稀释比。标准参考物质对照分析表明,实验建立的ID-ICP-MS方法可靠。对上海城区降尘中Pt和Pd测定发现,上海城区降尘中铂族元素的显著特征是Pd含量高于Pt含量,Pt和Pd含量呈线性正相关。

The method of isotope dilution-inductively coupled plasma mass spectrometry（ID-ICP-MS） was developed for the determination of Pt and Pd in road dustfall.195Pt and 108Pd were used as aim isotopes,196Pt and 105Pd as spikes.Dowex AG50W-8 cation exchange resin and solvent extraction with BPHA（N-Benzoyl-N-phenyl hydroxyl amine） were applied to separate the interference elements in matrix of dustfall.The mass discrimination of detected isotopes and optimal dilution ratios of spikes were determined.The analytical results of Pt and Pd in the certified reference materials BCR-723 and GBW07291 showed that the determination values of Pt and Pd were comparable with those standard values,which inducted that the ID-ICP-MS method was reliable.The ID-ICP-MS method was used for detection of Pt and Pd in dustfall in Shanghai City.It was found that the concentration of Pd was higher than Pt,and that the Pt concentration had positive linear correlation with Pd in the dustfall.