Determination of the palladium content in a solid plastic material by electrothermal vaporization ICP mass spectrometry (ETV-ICPMS)

Electrothermal vaporization inductively coupled plasma mass spectrometry (E TV-ICPMS) was used for the determination of the Pd content in a solid aliph atic polyketone. The presence of Pd in this material has to be attributed t o the use of a Pd-containing homogeneous catalyst for its production. By ap plication of a multi-step heating programme, the organic matrix could be se lectively and completely removed prior to the vaporization of the analyte e lement. The accuracy attainable when using (i) external calibration and (ii ) single standard addition using an aqueous standard solution was evaluated by comparison of the results obtained with a reference value obtained by m eans of neutron activation analysis (NAA). On the basis of its similar furn ace behaviour, Ir was shown to be perfectly suited to be used as an interna l standard. Also the argon dimer signal (Ar-2(+)) shows some potential to b e used as an internal standard, When using Ir or Art(2)(+) as an internal s tandard and single standard addition for calibration, the ETV-ICPMS result ( similar to 5 mu g g(-1))agreed within 10% with the NAA result on each occ asion (deviation between average ETV-ICPMS result and reference value simil ar to 2%), The absolute limit of detection (3s-criterion) was observed to b e similar to 1 pg, corresponding to a relative value of similar to 1 ng g(- 1), taking 1 mg as a typical sample mass. However, when using Ir as an inte rnal standard, it was established that the detection limit deteriorated to similar to 20 pg, due to the presence of a measurable amount of Pd in the I r standard solution.