An evaluation on the extraction capability of anion exchange membranes for high-precision sulfur isotope measurement by multiple-collector inductively coupled plasma mass spectrometry

Abstract

Anion exchange membranes (AEMs) are adept at extracting sulfate for sulfur isotope analyses by multiple-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) from natural samples typically with low sulfate concentrations.

Atomic spectrometry update – a review of advances in environmental analysis

“…Accurate determination of the sulfur isotope ratios of sulte, sulfate and thiosulfate in waters was achieved 84 in one analytical run by coupling IC to MC-ICP-MS. An S-containing IS (trimethylsulfoxide) was added to correct for mass bias, and oncolumn fractionation was corrected by external calibration. Use of a linear regression slope to calculate the isotope ratios of the transient signals resulted in a combined uncertainty of <0.25& for d 34 S in solution and a reproducibility of 0.5& for an injection of 1 mg of S. An anion-exchange membrane was evaluated 85 for the extraction of S from fresh and marine pore waters before determination of S isotope ratios by MC-ICP-MS. Recoveries were >90% when concentrations of competing ions (bicarbonate, carbonate, chloride, nitrate and phosphate) were limited to <0.5 mM per cm 2 of membrane. The lowest S concentration detectable without fractionation was 0.5 mM, but the recovery dropped at concentrations >0.01 mM probably as a result of reaching the breakthrough volume for the disc membrane.…”