A siliceous support grafted with poly[1-(N,N-bis-carboxymethyl)amino-3-allylglycerol-co-dimethylacrylamide] brushes for removal of nickel from environmental samples

Abstract

A system for the determination of nickel(II) after preconcentration on chelating adsorbent and elution with nitric acid is presented in this article. The adsorbent was synthesized by grafting the chelating polymer poly[1-(N,N-bis-carboxymethyl)amino-3-allylglycerol-co-dimethylacrylamide (poly(AGE/IDA-co-DMAA)) to silica gel. Ni(II) recoveries were above 92% when using 0.5 mol L⁻¹ nitric acid as eluting agent. The sorption capacity of the functionalized sorbent was 12.2 mg g⁻¹. The chelating sorbent can be reused for at least 15 cycles without any significant change in sorption capacity. The developed method was utilized for preconcentration and determination of Ni(II) in sea water samples by flame atomic absorption spectrometry. The 3σ detection limit and 10σ quantification limit for Ni(II) were found to be 0.5 and 1.7 µg L⁻¹, respectively. The equilibrium adsorption data of Ni(II) on modified sorbent were analyzed using Langmuir, Freundlich, Temkin, and Redlich–Peterson models. Based on equilibrium adsorption data, the Langmuir, Freundlich, and Temkin constants were determined as 0.0346, 1.286, and 53.73, respectively, at pH 4.5 and 20°C.

Keywords:

• solid phase extraction
• polymer grafting
• nickel
• preconcentration
• isotherm study