Determination of the rare earth elements in aqueous samples at sub-ppt levels by inductively coupled plasma mass spectrometry and flow injection ICPMS

A method has been developed for the determination of the rare earth elements (REE) at concentrations down to 0.1 ppt (0.5 pmol kg(-1)) in aqueous samples using now injection coupled to-an inductively coupled plasma mass spectrometer. The method presented here is an extension of an existing technique to allow application to a wider range of ionic strengths. The method is sufficiently rapid to enable samples to be processed through the purification stage in less than 90 min, More than 99.5% of the Ba in the sample is removed during processing, ensuring that isobaric interference of BaO on the REE is < 2% of the REE signal, The detection limits of the method described here show an improvement of up to 30 times better than the original method. This improvement was achieved by using how injection techniques that allow the sample to be concentrated in a smaller volume for analysis. The new technique has been successfully employed for the determination of REE in Icelandic hydrothermal fluids.