Determination of Rhenium in Groundwater by Inductively Coupled Plasma Mass Spectrometry with On-Line Cation Exchange Membrane Sample Cleanup

A scheme Is presented for determining rhenium in groundwater samples that contain up to 4000 mg/L dissolved solids by Inductively coupled plasma mass spectrometry. A commercially available cation exchange membrane cartridge is used on-line to exchange catlonlc species for equivalent quantities of hydrogen ion; rhenium, which is present as the perrhenate anion, remains on the upstream side of the membrane and is transported directly Into the Inductively coupled plasma. This arrangement successfully alleviates the matrix-related sample introduction difficulties and permits direct determination of rhenium In water with a detection limit of 0.03 μg/L using a Meinhard-type nebulizer. Removal efficiencies of up to 100% are achieved for sodium, magnesium, aluminum, potassium, and calcium ions, while perrhenate is transmitted with 100% efficiency. Results are presented for the determination of rhenium in groundwater samples from the vicinity of a metal sulfide tailings Impoundment In the western United States.