Ion Chromatographic Determination of Sulfate Ion in Carbonates and Chlorides of Rare Earth Elements After Separation by Cation Exchange Resin

Rare earth cations were separated on cation exchange resin column,and the anions (including SO2-4) in the effluent solution from the ion-exchange column,were further separated on AS 9 anion separation column (4 mm×250 mm) with 9.0 mmol·L-1 Na2CO3 solution as mobile phase.Conductivity detector was used in the measurements,and calibration curve was used in the determination.Detection limit of the method was found to be 0.05 mg·L-1,and the limit of determination was found as 0.03%.Value of RSD (n=11) found was 1.63% for SO2-4 content of 3.19%.Values of recovery obtained were in the range of 94.2%-112.6%.