Germanium speciation using liquid chromatography-inductively coupled plasma-triple quadrupole mass spectrometry: Germanium in biological and chemical leaching solutions of fine-grained residues from copper smelting.

A new method for the speciation analysis of inorganic germanium (Ge(OH)4), monomethylgermanium (MMGe) and dimethylgermanium (DMGe) in complex acidic aqueous leachates by liquid chromatography coupled to inductively coupled plasma mass spectrometry (LC-ICP-MS) was developed. The species are separated using anion exchange chromatography with tartrate added as complexing agent. When tartrate was added to the sample and the eluent chromatography was not affected by sulfate concentrations up to 100 mM. The He collision mode (MS/MS mode) removes polyatomic plasma- and matrix-based interferences, thus providing the selectivity in Ge speciation required for the complex samples. With LOQs of 62 ng L-1 (DMGe), 67 ng L-1 (MMGe) and 164 ng L-1 (Ge(OH)4) the method was sufficiently sensitive for the intended application. The developed method was applied to biological and chemical leachates of sulfidic flue dust from copper shale smelting (Theisen sludge). Only small amounts of methylated Ge species were determined next to inorganic Ge in these leachates.