Carbon-based magnetic nanocomposites in solid phase dispersion for the preconcentration some of lanthanides, followed by their quantitation via ICP-OES.

We report on a method for the extraction of the lanthanide ions La(III), Sm(III), Nd(III) and Pr(III) using a carbon-ferrite magnetic nanocomposite as a new adsorbent, and their determination via flow injection ICP-OES. The lanthanide ions were converted into their complexes with 4-(2-pyridylazo)resorcinol, and these were adsorbed onto the nanocomposite. Fractional factorial design and central composite design were applied to optimize the extraction efficiencies to result in preconcentration factors in the range of 141-246. Linear calibration plots were obtained, the limits of detection (at S/N = 3) are between 0.5 and 10 μg L, and the intra-day precisions ( n = 3) range from 3.1 to 12.8 %. The method was successfully applied to a certified reference material. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]