Investigation and mathematical correction of the matrix complexity effect on platinum group metals using inductively coupled plasma optical emission spectrometry determination

Abstract

Inductively coupled plasma optical emission spectrometry (ICP OES) has increasingly become a very advantageous method for the determination of platinum group metals (PGMs). However, PGMs feature high values and low contents and are susceptible to severe interference from complex matrices during determination, making quantitative analysis difficult. This work aims to establish an efficient analytical method for accurately determining PGMs even in the presence of severe matrix elemental interference. The 24 emission lines of PGMs were investigated using typical Fe–PGM alloys, and the spectral and non-spectral interferences of individual and combined matrix elements on the PGM determination were studied. Three reliable emission lines, Pd 324.270 nm, Pt 299.797 nm, and Rh 343.489 nm, were finally identified. Moreover, two mathematical correction methods were established, and the accuracy was verified by simulated solutions and fire assay. The relative errors (REs) of correction method I and II were within 5.49% and 2.88%, respectively, demonstrating good accuracy. Finally, an ICP OES method that facilitates necessary assessment for PGM leaching and separation for the accurate quantitative analysis of Fe–PGM alloys was established and it also provides a useful reference for the determination of other PGM-containing materials.