Improvements in Digestion Protocols for Trace Element and Isotope Determinations in Stream and Lake Sediment Reference Materials (JSd-1, JSd-2, JSd-3, JLk-1 and LKSD-1) |
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Authors: | Sidonie Révillon Danièle Hureau-Mazaudier |
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Institution: | Universitéde Brest, CNRS, UMR 6538 Domaines Océaniques, Institut Universitaire Européen de la Mer, Place Copernic, 29280 Plouzané, France;IFREMER, Département Géosciences Marine, BP 70, 29280 Plouzané, France |
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Abstract: | Total dissolution is a critical step in geochemical analysis. Despite the number of published protocols, this issue still draws attention for sediment samples, which are particularly difficult to dissolve due to the common occurrence and high abundance of refractory phases such as zircon. We present tests of different chemical digestion procedures carried out on reference materials (RM) of stream (JSd-1, JSd-2 and JSd-3) and lake (JLk-1 and LKSD-1) sediments from the Geological Survey of Japan (GSJ) and the Canadian Certified Reference Material Programme (CCRPM). We demonstrate that the fusion technique is not appropriate for our studies as not all elements of interest were recovered and blank levels were too high to permit further Sr and Pb isotopic composition measurements. Similarly, conventional HF+HNO3 dissolution methods were not efficient enough for detrital samples. Our preferred method involved using high pressure Teflon® vessel bombs in association with HClO4. This protocol ensured a complete dissolution of the powder, as well as a complete recovery of trace elements. Moreover, blank levels were sufficiently low that Sr or Pb isotope compositions could be measured from the same mother solution. We also tested the homogeneity of RM powders by performing tests on various amount of powder. |
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Keywords: | RM HR-ICP-MS acid digestion fusion sediment |
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