Determination of Pt, Pd, Ru and Ir in geological samples by ID-ICP-MS using sodium peroxide fusion and Te co-precipitation

Abstract

A method is proposed for the determination of Pt, Pd, Ru and Ir in geological samples by isotope dilution-inductively coupled plasma mass spectrometry (ICP-MS). Mono-isotopic elements Rh and Au are determined by external calibration using Lu as the internal standard. Sodium peroxide fusion in corundum crucibles (instead of glassy carbon or zirconium crucibles) is used to decompose the samples. After dissolution of the fused cake in water, the solution is spiked with enriched stable isotopes of Pt, Pd, Ru and Ir, and then acidified with HCl. This solution is then evaporated to dryness promoting the formation of anhydrous silicate from colloidal material. PGEs and Au are then pre-concentrated by Te co-precipitation.The reagents HCl and SnCl 2 are purified by Te co-precipitation. PGE blank levels are thus only derived from the Na 2 O 2 which has PGE concentrations of <0.02 ng/g. Lutetium is added as the internal standard to correct for instrument drift and matrix suppression effects for the determination of the monoisotopic elements. Method detection limits range from 0.02 to 0.3 ng/g. The results obtained for the CCRMP (CANMET, Ottawa, Canada) certified reference materials WGB-1 (gabbro), TDB-1 (diabase), UMT-1 (ultramafic ore tailings), WPR-1 (altered peridotite), WMG-1 (mineralized gabbro), and WMS-1 (massive sulphide) are in good agreement with certified values.

Petrology, mineralogy, porosity, and cosmic‐ray exposure history of Huaxi ordinary chondrite

“…Five platinum group elements, including Ru, Rh, Pd, Pt, and Ir, were measured with a Finnigan MAT ELEMENT magnetic sector ICP‐MS using a 200 mg aliquot of the solution and applying the method described in Qi et al. (, ). Four fragments of Huaxi with masses of 2.29, 3.82, 2.84, and 3.26 g were used for the determination of densities and porosities with a Micro‐ultrapyc 1200e ideal gas pycnometer and applying the method developed by Li et al.…”

Evaluation of a technique for determining Re and PGEs in geological samples by ICP-MS coupled with a modified Carius tube digestion

“…The determination of PGEs in geological materials is difficult because of their low abundance and heterogeneous distributions and the complexity of sample preparation. Methods for dissolving geological samples and thereby for concentrating PGEs include nickel sulfide (NiS) fire assay coupled with Te coprecipitation (Jackson et al, 1990;Zhou et al, 2001;Gros et al, 2002;Juvonen et al, 2002;Sun and Sun, 2005), acid attack combined with Na 2 O 2 fusion (Morgan and Walker, 1989;Yi and Masuda, 1996;Dai et al, 2001;Qi et al, 2003Qi et al, , 2004, aqua regia dissolution in a sealed Carius tube, and high pressure asher (HPA-S) (Shirey and Walker, 1995;Cohen and Waters, 1996;Rehkämper et al, 1998;Pearson and Woodland, 2000;Brauns, 2001;Meisel et al, 2001Meisel et al, , 2003aMeisel et al, , 2003bPretorius et al, 2003;Meisel and Moser, 2004). The advantages and disadvan-bration between spikes and samples.…”

Determination of Platinum‐Group Elements in OPY‐1: Comparison of Results using Different Digestion Techniques

“…The SnCl 2 solution (20% w/v) was prepared by dissolving 50 g of SnCl 2 in 250 ml of 6 mol l -1 HCl. The Te-coprecipitation method was used to purify this solution from PGEs (Qi et al 2003). Analytical reagent-grade Na 2 O 2 and 30 ml corundum crucibles were used for the alkaline fusion.…”