车用陶瓷催化转化器样品经氢氟酸和硝酸-盐酸(3+4)溶液消解后,再用氢氧化钠与未溶的氧化铝反应生成偏铝酸盐,然后再加入硝酸-盐酸(1+3)溶液溶解,采用电感耦合等离子体质谱法测定所得样品溶液中铂、钯和铑等3种贵金属元素的含量。选择适当的待测元素的同位素及校正方程克服了质谱干扰,采用稀释法有效地校正了非质谱干扰。结果表明:方法的检出限(3s)在0.01~0.14 μg·L-1之间。方法用于车用陶瓷催化转化器样品中3种贵金属元素的测定,回收率在93.2%~98.0%之间,测定值的相对标准偏差(n=6)在0.63%~1.5%之间。

The sample of car-use ceramic catalytic converter was digested with HF and HNO3-HCl (3+4) solution, and the undissolved Al2O3 was reacted with NaOH to form mataaluminate, which was dissolved with HNO3-HCl (1+3) solution. The contents of 3 precious metal elements, i.e., Pt, Pd and Rh in the sample solution were determined by ICP-MS. Appropriate isotopes of the elements determined and correction equations were selected to overcome the mass spectrometric interferences, and dilution of sample solution were adopted to overcome the non-mass spectrometric interferences. Values of detection limit (3s) for the 3 elements were found in the range of 0.01-0.14 μg·L-1. The proposed method was applied in the analysis of substantial sample, giving values of recovery and RSD′s (n=6) in the ranges of 93.2%-98.0% and 0.63%-1.5% respectively.