Application of LA-ICP-MS in polar ice core studies

• Main Authors: Reinhardt, Heiko, Kriews, Michael, Miller, Heinrich, Lüdke, C., Hoffmann, E., Skole, J.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: 2003
• Subjects: Greenland; Greenland ice core; ice core
• Online Access: https://epic.awi.de/id/eprint/6069/; https://hdl.handle.net/10013/epic.16619

Abstract: The direct determination of element signatures in polar ice core samples from Greenland by laser ablation with subsequent inductively coupled plasma mass spectrometry analysis has been investigated. A cryogenic sample chamber enables the element determination in ice directly from the solid (frozen) state. A procedure was developed to analyse up to 38 elements (traces: Mg, Al, Fe, Zn, Cd, Pb and rare earth elements; minor constituents: Na) in ice samples from Greenland with a previously not achieved spatial resolution of 4 mm along the core axis. This resolution is helpful to detect seasonal variations of element concentration in thin annual layers of deep-ice. We report operating conditions and analytical performance of the experimental set up, the improvement of signal stability by 17OH internal standardisation and applying of a desolvation unit. Calibration of the system was performed with frozen multielement standard solutions along a special preparation procedure. Detection limits for the tracers Na, Mg (sea salt), Al (mineral dust) and Zn (anthropogenic source) are between 0.1-1 µgkg-1. Best detection limits in the range of 0.001-0.01 µgkg-1 were reached for Co, Pb and all rare earth elements. To validate the method, frozen standard reference materials were measured. The recovery is about ± 10 %. Greenland ice core samples from different ages were analysed with the new technique. The results obtained by laser ablation were compared with values from solution analysis, available published data and the particle content. Most elements have shown good correlation with the particle content in the Greenland samples, however, differences could be seen between the values obtained by laser ablation and solution bulk analysis after a tri-acid digestion. The influence of particles is discussed. The high spatial resolved 2d-mapping of element concentrations show strong inhomogeneities along the core axis most probably due to seasonal variations of element deposition.Key words: LA-ICP-MS ice core 2d-mapping ...