Evaluation of REE Determination in Geological Samples by Inductively Coupled Plasma Emission Spectrometry

Rare earth elements were separated from ten intemational geological reference samples by the classical ion-exchange chromatographic technique. Concentrations of ten rare earth elements were measured by inductively coupled plasma emission spectrometry. Comparison with the conensus values show a fairly good accuracy (<10%) for all the elements except for Lu. REE data for MB-H a metabasic reference sample and G-2, a granite reference sample have been compiled to determine the long term precision. A RSD value of 5-8% for La, Ce, Nd, Sm, Eu, Gd, Dy, Er and Yb indicates good reproducibility of our values. RSD for Lu was found to be high and it reaches up to 22% in G-2. The high RSD and poor accuracy for Lu in some samples is mainly attributed to low abundance level of this element which is very close to its detection limit. Ce, Gd and Sm are preferred to be analysed against a separated REE fraction of a rock standard having similar matrix to avoid the interferences. However, rest of the REEs can be comfortably measured against a salt standard.