On-line Preconcentration of Rare Earth Element by FIA-ICP-AES

A mini-column filled with Dowex 50x8 resin is developed and investigated for the analysis of trace level of rare earth element by ICP-AES. The column is installed between peristaltic pump and ICP-AES, and ng/ml level of rare earth element is analyzed directly by on-line FIA-ICP-AES. 6N hydrochloric acid is found to be an optimum concentration for stripping, and the optimum flow rates for loading and stripping are measured at 0.8 and 1.1ml./min, respectively. Easily ionized elements from flux such as Na and K would be eliminated easily by 2N hydrochloric acid before stripping the rare earth element deposited on the resin. For an analysis of Sm, the absolute detection limit and linearity are found to be and 0.9999, respectively. Less than 4% of reproducibility is observed for the analysis of Sm and Nd. The analytical result with NIST SRM 1633B is also found to be 20.3ng/ml, which agrees well with the certified value.