Determination of transition and rare earth elements in seawater by flow injection inductively coupled plasma time-of-flight mass spectrometry

Abstract

A method is presented for the quantitation of trace elements and rare earth elements (REE) in seawater by inductively coupled plasma orthogonal acceleration time-of-flight mass spectrometry. On-line separation and preconcentration was achieved using a timed flow-injection (FI) system incorporating a column containing iminodiacetate-based resin. The procedure was validated for selected transition elements by analysis of certified seawater reference materials NASS-5 and CASS-4. Recoveries of the rare earth elements (REE) from seawater were between 96 and 101%. Limits of detection (3 s) were generally in the 20–50-pg l −1 range with nominal precision of 5–6% R.S.D. ( n=5) when processing 50-ml sample aliquots of seawater. Sample throughput was 5 h −1 for the REE determinations and 15 h −1 for the transition elements of interest.