the present work concerns on the investigation of the role of polyethylene glycols (pegs) as masking agent for amelioration of extraction-separation of la(iii), eu(iii) and er(iii) ions by the acidic extractant bis(2-ethylhexyl)phosphoric acid (dehpa). the studied solvent extraction system is based on the combination of chelating effect of dehpa in the organic phase on the one hand, and the bin...