Nanocomposite Magnetite-Kaolin for Rh Preconcentration and Determination by Electrothermal Atomic Absorption Spectrometry.

A preconcentration technique with a magnetite-kaolin adsorbent capable of magnetic separation was developed for the determination of rhodium in environmental samples. The magnetite-kaolin nanocomposite was prepared for the preconcentration of rhodium in an aqueous solution prior to an electrothermal atomic absorption spectrometric determination. The detection limit (3S/N) of rhodium was 16 pg mL under the optimum conditions. Even though matrix elements existed in 10 fold excess in aqueous solution, the rhodium adsorption could be not affected by the matrix. The present method could be applied to the determination of Rh in an aqueous solution. The advantages are easy preparation of the adsorbent and fast magnetic separation.