Lithium, magnesium and sulfur purification from seawater using an ion chromatograph with a fraction collector system for stable isotope measurements

摘要

HighlightsAn offline ion chromatography separation is applied for stable isotope measurements.Sub-fraction mass fractionation was observed for both Li and Mg isotope ratios.δ7Li, δ26Mg, and δ34S of seawater were in good agreement with the published values.AbstractWe describe the mass descrimination and validation of an offline method for purification of Li, Mg and S with an ion chromatograph coupled to an automated fraction collector for use prior to stable isotope measurements. Significant sub-fraction mass fractionation was observed for both the Li and the Mg stable isotope ratios. The lighter Li and heavier Mg isotopes were preferentially retained by the column, resulting in7Li/6Li and26Mg/24Mg biases up to 85.8‰ and 0.95‰, respectively. The isotopic compositions of Li, Mg, and S separated from seawater were δ7LiL-SVEC?=?+30.9‰, δ26MgDSM3?=??0.83?±?0.10‰, and δ34SVCDT