Determination of the rare-earth elements in geological materials by thin-film X-ray fluorescence and inductively-coupled plasma atomic-emission spectrometry

Thin-film XRF and ICP-AES analytical procedures for the determination of the rare-earth elements (REE) in rocks, involving preeoncentration by ion-exchange and co-precipitation with Fe(OH) 3 for thin-film preparation, and matrix modification, are described. The REE in five international reference rocks have been determined, with correction for spectral line overlap whenever necessary. The results obtained by using X-ray fluorescence spectrometry compare well with those of inductively-coupled plasma atomic-emission spectrometry, and with other values reported in the literature.