Development and application of an analyte/matrix separation procedure for multi-element trace analysis of steel alloys by means of sector-field ICP-mass spectrometry

An analytical procedure, based on the use of sector-field ICP-mass spectrometry (ICP-SFMS), was developed for the determination of Be, B, Al, P, S, Ti, Ge, As, Se, Zr, Nb, Rh, Pd, Sn, Sb, Hf, Ta, W, Re, Ir and Pt in a high-alloy steel matrix, consisting mainly of Cr, Fe and Ni, in addition to lower amounts of Si, V, Mn, Co, Cu and Mo. To reduce the impact of spectral and non-spectral interferences, an analyte/matrix separation procedure based on cation-exchange chromatography was developed and applied. In the chromatographic protocol used, most of the first row transition metals are retained on AG 50Wx8 resin, whereby ca. 97.5% of the initial matrix can be separated from the rapidly eluting target elements. The experimentally determined concentrations for three CRMs were found to be in good agreement with certified values. For elements not natively found in the CRMs or the real samples under study, recoveries of ca. 100% were obtained when analysing mock samples. Procedural limits of quantification were found to range from low ng/g levels for Re to sub-mg/g levels for S.