Determination of 17 Trace Impurity Elements in Sponge Palladium by Inductively Coupled Plasma Mass Spectrometry with Standard Addition Method

The sponge palladium sample (0.900 0 g) was wet in 10 mL of water, and dissolved in 10 mL of a mixture of hydrochloric acid and nitric acid at a volume ratio of 3∶1 at 100 ℃. Water was added to the above solution to make the mass of solution attained to 90 g. The isotope to be tested was determined through mass spectrometry interference analysis combined with isotope abundance, and ⁵²Cr, ⁵⁶Fe, and ⁵⁵Mn were detected in dynamic reaction cell (DRC) mode, while isotopes of other elements were detected in standard mode. 17 trace impurity elements in sponge palladium were determined by inductively coupled plasma mass spectrometry (ICP-MS) under the conditions of radio frequency power at 1 100 W and atomization gas flow at 0.85 L·min^-1. The calibration curves for elements were drew by standard addition method, and the working curves were set through “external standard method” mode with instrument software. Subsequent testing for other sponge palladium samples could be directly carried out under those working curves, without standard addition method for each sample. As shown by the results, values of detection limit (3s) for 17 elements were in the range of 0.012-0.452 μg·g^-1. Test for recovery was made by standard addition method, giving results in the range of 93.0%-107%, with RSDs (n=11) of the determined values less than 8.0%. The comparison analysis of sponge palladium samples by this method and inductively coupled plasma atomic emission spectrometry in GB/T 1420-2015 was carried out, and it was shown that the determined results obtained by the two methods were basically consistent.