A particular ion chromatographic method for yttrium determination after separation from dysprosium simultaneously with individual quantification of rare earth elements has been modified. Selective separation of yttrium from dysprosium plus the other thirteen rare earth elements was achieved by gradient elution using oxalic / diglycolic acid eluent mixture on IonPac CS5A separating column. The separated ions were then detected using 4-(2-pyridylazo)resorcinol (PAR) at 530 nm. The optimized method was subsequently validated by the analysis of a reference sample from Abu Rusheid area followed by its application on two geological materials from Wadi Khuda-Wadi Shut area and Abu Tartour phosphate deposits. Relative standard deviation (RSD) calculated for the analyzed samples were expressed with very low values the matter which confirms the precision of the developed method. The present work allowed the individual determination of lanthanide elements including yttrium and six heavy metal ions in an absolute time of about 110 minutes.