seaFAST REE ICPMS for Preconcentration and Detection of Rare Earth Elements in Undiluted Seawater

ESI's seaFAST is a fully-automated online system that improves elemental detection limits in undiluted seawater by both preconcentrating analyte and eliminating matrix components. The seaFAST is well-established for determining transition metals in coastal and open-ocean seawaters. This note explores the effectiveness of the seaFAST system in detecting ppq and low ppt concentrations of rare earth elements (REE) in seawater.

With the seaFAST, targeted elements from an aliquot of sample are trapped on a mixed resin preconcentration column while the matrix ions, such as Na+ and Cl-, pass through to waste. Nitric acid then elutes the concentrated metals from the column into the ICPMS nebulizer. The seaFAST system automates the entire process, eliminating the time-consuming and contamination-prone steps involved in manual preconcentration and matrix removal.

Experimental

Procedure
Calibration standards were prepared in 1% nitric acid. The pre-acidified (pH 2) seawater samples (NASS-5) were analyzed neat. The sample was vacuum-loaded into a loop and injected onto the column. After preconcentration and matrix removal in the column, the REEs were eluted from the column directly into the ICPMS by 8% HNO3 (v/v), and the column was reconditioned prior to analyzing the next sample.

Results
Calibration standards measured in 1% HNO₃ acid show excellent linearity from ppq to >10 ppb. Shown here is the low end of the calibration curve.