ICP-SFMS determination of palladium using IDMS in combination with on-line and off-line matrix separation

Two analytical strategies for the determination of Pd in geological and environmental matrices were evaluated in terms of accuracy and precision. Pd was quantified at ng g−1 levels using microwave-assisted digestion including aqua regia–HF followed by on-line HPIC-ICP-SFMS (high performance ion chromatography-inductively coupled plasma-sector field mass spectrometry) and off-line anion exchange with quantification by IDMS. With the HPIC method, separation of Pd from the interfering elements Cu, Zn, Rb, Sr, Y, Zr, Mo, and Cd was achieved within 14.5 min by using 2,6-pyridinedicarboxylic acid as complexing agent. Absolute detection limits of 13 pg and 70 pg were achieved for the on-line and off-line method, respectively. The methods have been evaluated using the certified reference materials WPR-1 (altered peridotite), WGB-1 (gabbro rock) and the candidate reference material CW8 (road dust).