A composite prepared from halloysite nanotubes and magnetite (Fe3O4) as a new magnetic sorbent for the preconcentration of cadmium(II) prior to its determination by flame atomic absorption spectrometry

A magnetic nanocomposite (m-NC) was prepared from halloysite nanotubes and magnetite (Fe3O4) by chemical precipitation and used as an effective sorbent for preconcentration of trace quantities of cadmium(II). The m-NC was characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy and energy dispersive X-ray spectroscopy. Preconcentration is based on the adsorption of the cationic Cd(II)-1,10-phenanthroline complex on the negatively charged m-NC. Parameters that affect complex formation and subsequent adsorption and desorption were optimized. The preconcentration factor is 50. Cd(II) was then quantified by flame AAS. The calibration graph is linear in the 0.5 to 50 mu ga (TM) LaEuro3/4(1)concentration range, and the detection limit is 0.27 mu ga (TM) L-1. The method was applied to the determination of traces of Cd(II) in spiked waters, nail and hair samples. Recoveries ranged from 96.7 to 104.2 %.