Double-Imprinted Cross-Linked Poly(Acrylamide-co-Ethylene Glycol Dimethacrylate) as a Novel Sorbent for the On-Line Preconcentration and Determination of Copper(II) by Flame Atomic Absorption Spectrometry

Abstract

An on-line preconcentration system was coupled to flame atomic absorption spectrometry (FAAS) for the determination of copper(II) in water using poly(acrylamide-co-ethylene glycol dimethacrylate) synthesized via a hierarchical double-imprinting process. The on-line preconcentration procedure was based on loading the sample into a minicolumn packed with the synthesized material, followed by elution with 1.8 mol L−1 HNO3. To achieve the highest performance, the method was optimized by 25-1 fractional and 22 full factorial designs. Under the optimum conditions, the following analytical parameters were obtained: detection limit of 0.48 µ gL−1, quantification limit of 1.61 µgL−1, preconcentration factor of 31.0, consumption index of 0.58 mL, preconcentration efficiency of 8.63 min−1, and sample throughput of 15 h−1. The precision of the method was evaluated as the relative standard deviation (n=10) of 10.0 and 150.0 µgL−1 copper(II), yielding values of 3.27% and 1.97%, respectively. The analytical efficacy of the proposed method was justified by successful determination of copper(II) in water. The synergistic effects of copper(II) and cetyl trimethylammonium bromide, employed as templates, improved the preconcentration, thus improving the method without the double imprinting effect.