Chelating Resin Based on Silica Gel for Solid-Phase Extraction Coupled with Flame Atomic Absorption Spectrometric Determination of Nickel and Cadmium

Chelating resins offer a fast, accurate and simple method for separation and preconcentration of metal ions at low concentrations prior to their determination by an instrumental method. Silica gel-based chelating resin with chemically immobilized aurintricarboxylic acid was synthesized, characterized and used to determine Ni(II) and Cd(II) at trace levels, coupled with their analysis by flame atomic absorption spectrometer. The resin had sorption capacities of 0.21 mmol g-1 and 0.10 mmol g-1 for Ni(II) and Cd(II), respectively. The analytical detection limit (N = 20) was 1.70 μg L-1 for Ni(II) and 1.90 μg L-1 for Cd(II). The proposed method was useful for the quantitative determination of Ni(II) and Cd(II) in some commercial and water samples.