Continuous flow analysis methods for sodium, magnesium and calcium detection in the Skytrain ice core

• Published in: Journal of Glaciology
• Main Authors: Mackenzie M. Grieman, Helene M. Hoffmann, Jack D. Humby, Robert Mulvaney, Christoph Nehrbass-Ahles, Julius Rix, Elizabeth R. Thomas, Rebecca Tuckwell, Eric W. Wolff
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press 2022
• Subjects: Glaciological instruments and methods; ice core; paleoclimate; Environmental sciences; GE1-350; Meteorology. Climatology; QC851-999; Antarctic; Skytrain Ice Rise; The Antarctic; Antarc*; Journal of Glaciology; Sea ice
• Online Access: https://doi.org/10.1017/jog.2021.75; https://doaj.org/article/11c0b92f81d547fd9036add7658c9dcb

Dissolved and particulate sodium, magnesium and calcium are analyzed in ice cores to determine past changes in sea ice extent, terrestrial dust variability and atmospheric aerosol transport efficiency. They are also used to date ice cores if annual layers are visible. Multiple methods have been developed to analyze these important compounds in ice cores. Continuous flow analysis (CFA) is implemented with instruments that sample the meltstream continuously. In this study, CFA with ICP-MS (inductively coupled-plasma mass spectrometry) and fast ion chromatography (FIC) methods are compared for analysis of sodium and magnesium. ICP-MS, FIC and fluorescence methods are compared for analysis of calcium. Respective analysis of a 10 m section of the Antarctic WACSWAIN Skytrain Ice Rise ice core shows that all of the methods result in similar levels of the compounds. The ICP-MS method is the most suitable for analysis of the Skytrain ice core due to its superior precision (relative standard deviation: 1.6% for Na, 1.3% for Mg and 1.2% for Ca) and sampling frequency compared to the FIC method. The fluorescence detection method may be preferred for calcium analysis due to its higher depth resolution (1.4 cm) relative to the ICP-MS and FIC methods (~4 cm).