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 main matrix constituents accompanying the rapidly eluting target elements are Si, Mo and ca. 5% of the total Cr, the latter of which unavoidably elutes prematurely. The finalised procedure was applied to CRMs and real high-alloy steel samples (T91, 316L and 15-15Ti). The experimentally determined concentrations for the CRMs were found to be in good agreement with certified values. Analysis of the real samples revealed the presence of measureable amounts of most of the target elements in at least one of the three steels, with the exception of Be, S, Se, Hf and Ir. For elements not natively found in the CRMs or the real samples under study, recoveries of 100% (within reproducibility uncertainty) were obtained when analysing mock samples. Procedural limits of quantification (10s LoQs) were determined by subjecting blanks to the entire procedure. These were found to range from low ng g(-1) levels for Re to sub-mg g(-1) levels for S

On the determination of trace elements in lead-bismuth eutectic by means of sector-field inductively coupled plasma-mass spectrometry

Double-focusing sector-field inductively coupled plasma-mass spectrometry (ICP-SFMS) was used for the determination of trace amounts of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Nb, Mo, Ag, Cd, Te, Ce, Re, Tl, Th and U in lead-bismuth eutectic (LBE). To eliminate matrix effects, an offline analyte/matrix separation procedure was applied. This procedure is based on a combination of extraction chromatography and anion-exchange chromatography. The matrix elements Pb and Bi could be quantitatively separated from the vast majority of the target elements. In all fractions containing target elements, less than 0.5% of the LBE matrix remains. It was shown that the target elements could be quantitatively separated from "mock" samples, which contained ca. 20 000 mg L-1 of the matrix elements and ca. 0.2 mg L-1 of the target elements. For two lead-matrix certified reference materials, IMN PL33 & IMN PL66, experimentally determined concentrations for Ni, Cu, Ag, Cd, Tl and Bi were shown to be in good agreement with the corresponding certified values. A discrepancy was only found for Te in CRM IMN PL66, for which a recovery of only ca. 30% was obtained. Results obtained with the procedure for Cu, Ag and Cd in a series of five real LBE samples are in good agreement with those obtained by means of neutron activation analysis (NAA). Limits of quantitation (LoQ, 10s) ranged from sub-mu g g(-1) levels for the contamination-prone Fe to low ng g (1) levels for Th

Direct determination of Pd, Pt and Rh in fire assay lead buttons by laser ablation-ICP-OES : automotive exhaust catalysts as an example

The increasing use of Pd, Pt and Rh as catalysts in industrial applications results in the necessity of fast and accurate methods for the determination of these elements, not only in natural sources, but also in recyclable materials, such as spent automotive exhaust catalysts. Because of the low Pd, Pt and Rh contents in the samples typically analyzed and in order to avoid the influence of matrix components and sample heterogeneity, trace/matrix separation by means of lead fire assay usually precedes the actual analysis. This article concentrates on the determination of Pd, Pt and Rh in lead buttons obtained via fire assay using laser ablation-optical emission spectrometry. A 266 nm Nd:YAG-based laser ablation unit offering a maximum laser beam diameter of 780 mm was coupled to an ICP-OES instrument permitting simultaneous monitoring of the entire spectrum owing to the use of linear CCD detectors mounted on a Rowland circle of a spectrometer in Paschen-Runge mounting. Matrix-matched standards were applied for the construction of calibration curves, which were subsequently used for analysis of some real-life samples. The three different acquisition methods available were evaluated, but turned out to be quite similar in terms of linearity, accuracy and detection power. All but two of the resulting regression coefficients of the calibration curves were >= 0.999, while, taking into account their uncertainty, the experimental results are in good agreement with the reference values (obtained via wet chemical analysis) for the real-life samples analyzed, Pb buttons prepared by fire assay of an automotive exhaust catalyst. Limits of detection vary between 2.5 and 12 mu g g(-1) in the Pb button and the method precision was shown to be typically better than 5%

Studies of the protonation in aqueous-solution of l-thia-4,7-diazacyclononane, l-thia-4,8-diazacyclodecane and 5-thia-2,8-diazanonane

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