Synthesis and application of 5-amino-2-benzotriazol-2-yl-phenol for preconcentration and determination of zinc (II) in water samples by flame atomic absorption spectrometry

Abstract

A novel spherical 5-amino-2-benzotriazol-2-yl-phenol (ABP) chelating sorbent is synthesized simply and rapidly from 2-nitroanilin and 3-nitrophenol characterized (IR, 1H NMR spectra and scanning electron microscopy) and studied for the preconcentration and determination of trace Zn(II) ion from aqueous solution samples. The concentration of metal ion in the solution was determined by flame atomic absorption spectrometry (FAAS). The optimum pH value for sorption of the metal ion was 6.5. The sorption capacity of ABP for Zn(II) was determined. The chelating ABP can be reused for 20 cycles of sorption-desorption without any significant change in sorption capacity. A recovery of 86% was obtained for the metal ion with 0.5 M HNO₃ as eluting agent. The equilibrium adsorption data of Zn(II) on sorbent were analyzed by the Langmuir and Freundlich models. Based on equilibrium adsorption data the Langmuir and Freundlich constants were determined 0.0074 and 1.200 at pH 6.5 and 25°C.

Keywords:

• Solid phase extraction
• 5-amino-2-benzotriazol-2-yl-phenol
• Zinc
• Immobilization
• Isotherm study