Direct determination of trace levels of Os, Ir, Ru, Pt and Re in kimberlite and other geological materials using HR-ICP-MS

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

“…Because of their low procedural blank compared to other techniques, these techniques leach and partially dissolve samples in a highly oxidizing solution (aqua regia) and can achieve full isotopic equilibration between spike and sample and avoid the loss of volatile species such as OsO 4 . The amount of aqua regia normally used is less than one third of the total volume of the Carius tube with a temperature of about 220-240°C (Shirey and Walker, 1995;Cohen and Waters, 1996;Pretorius et al, 2003), because larger volumes and/or higher temperatures may rupture and create an explosion hazard.…”

“…The Carius tube technique and HPA-S are often used for digesting refractory PGE minerals in geological samples and Re-Os isotopic analyses (e.g., Shirey and Walker, 1995;Pearson and Woodland, 2000;Brauns, 2001;Meisel et al, 2003a, b;Pretorius et al, 2003;Meisel and Moser, 2004). Because of their low procedural blank compared to other techniques, these techniques leach and partially dissolve samples in a highly oxidizing solution (aqua regia) and can achieve full isotopic equilibration between spike and sample and avoid the loss of volatile species such as OsO 4 .…”

“…The autoclave is of low cost and easy to maintain. Because methods for PGE pre-concentration and measurement were reported by many papers (Shirey and Walker, 1995;Birck et al, 1997;Rehkämper et al, 1998;Pearson and Woodland, 2000;Meisel et al, 2001;Jensen et al, 2003;Pretorius et al, 2003), we focus on the efficiency of this modified technique for digesting geological samples at different temperature.…”

“…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.…”

Inductively coupled plasma- and glow discharge plasma-sector field mass spectrometry : Part II. Applications

“…9 pg g À1 for Re, 2 pg g À1 for Ru, 3 pg g À1 for Ir and 10 pg g À1 for Pt. 163 In total 39 geologically relevant trace elements were quantified accurately and directly by ICP-SFMS in digests of granitoid reference materials G-2 and GSP-2 by Pretorius et al 164 Several of these elements had to be determined at a mass resolution of 4000 or 10000 to remove spectral interferences.…”