ONLINE SEPARATION AND PRECONCENTRATION FIA-ICP-AES SYSTEM FOR SIMULTANEOUS DETERMINATION OF REES AND YTTRIUM IN GEOLOGICAL SAMPLES

A method utilizing a dual-column on-line ion-exchange FLA system coupl ed with ICP-AES is investigated for the simultaneous determination of 14 rare earth elements (REEs) and yttrium in geological samples. Conic ally shaped ion-exchange columns of HEH(EHP) were used for loading and eluting. Nitric acid (3.5 mol/L) was chosen for the simultaneous elut ion of the REEs and yttrium. Peak area integration mode of ICP-AEs was adopted for the determination. Samples of 0.1 gram and a sampling fre quency of 14/h were used. Limits of detection for the 14 REEs and yttr ium were 0.05-0.5 mu g/g with a relative standard deviation of 5-10%. The signal enhancement factor for 15 test elements was between 8-15 an d % recovery between 785-102%. Twenty samples per batch were analyzed in one day which is sevenfold faster than the conventional method. Nat ional Geological Standard samples of the GSD, GSS and GSR series were analyzed to prove the validity of the approach. The analytical results are in good agreement with the certified values.