Novel Functionalized Silica Gel for On-line Preconcentration of Cadmium(II), Copper(II), and Cobalt(II) with Determination by Flame Atomic Absorption Spectrometry

ABSTRACT

Silica gel functionalized with 2-[N,N’-bis(2,3-dihydroxybenzaldimin)] aminoethylamine was employed as a novel sorbent for preconcentration of copper(II), cobalt(II), and cadmium(II) by flow injection-solid phase extraction. The pH of the analyte solution, sample and eluent flow rate, eluent volume, and the presence of concomitant ions were optimized. The limits of detection were 0.65, 0.52, and 1.42 µg/L and preconcentration factors were 12.3, 21.5, and 7.31 for cadmium(II), copper(II), and cobalt(II), respectively. The adsorption capacities of the functionalized silica gel for cadmium(II), copper(II), and cobalt(II) ions were 41.1, 31.7, and 26.5 mg/g. The preconcentration method was validated by determination of cadmium(II), copper(II), and cobalt(II) levels in Virginia Tobacco Leaves (CTA-VTL-2) and Water-Trace Elements (NWTM-15.2) certified reference materials. The method was also used to analyze water and food samples, and offers simplicity, reproducibility, high recovery, rapid and automated analysis, favorable ease of use, and low detection limits.

KEYWORDS:

• 2,3-dihydroxybenzaldehyde
• flame atomic absorption spectrometry
• flow injection
• modified silica gel
• on-line preconcentration
• solid phase extraction