A novel nanoadsorbent Ni/Ni_xB for preconcentration of arsenic(III) and arsenic(V) before hydride generation-atomic absorption spectrometric determination

Abstract

A novel adsorbent named Ni/Ni_xB nanoparticles was synthesized for the preconcentration of both As(III) and As(V) from water samples. Both adsorbent preparation and adsorption procedure were optimized. The adsorption efficiencies for both As(III) and As(V) were higher than 99% when the initial pHs ranged from 4.0 to 10.0. The rate of the adsorption was high, and in the first 10 min, the adsorption efficiency reached 95%. Adsorbed As(III) and As(V) were recovered with high efficiencies from the adsorbent using 2 mol L⁻¹ HCl. Under the optimal conditions, an enrichment factor of 50 was reached. Hundred-fold excess of Cd²⁺, Cu²⁺, Mg²⁺, Zn²⁺, K⁺, , , and ions did not affect the adsorption efficiencies of As(III) and As(V). The adsorption for both As(III) and As(V) obeyed the Freundlich and Langmuir isotherms. The maximum adsorption capacities calculated from the Langmuir isotherm were 2,500 mg g⁻¹ for both species, and the adsorptions were favorable. The validation and the real sample application studies showed that the adsorbent was appropriate for the preconcentration of both As(III) and As(V) from water samples.

Keywords:

• Nanoparticles
• Arsenic
• Preconcentration
• Hydride generation
• Atomic absorption spectrometry

Acknowledgments

We would like to thank Ege University Research Fund for the financial support of this study, Project No. 2010 FEN 079. Yasemin İşlek Coşkun also thanks the Scientific and Technological Research Council of Turkey (TUBITAK) for scholarship during this study.