Separation of ruthenium from environmental samples on polymeric sorbent based on imprinted Ru(III)-allyl acetoacetate complex

Abstract

A new ion imprinted polymer (IIP) for ruthenium recognition/pre-concentration was prepared via bulk polymerization using methacrylic acid as the functional monomer and ethylene glycol dimethacrylate as the cross-linking agent in the presence of Ru(III)-allyl acetoacetate complex as a template. The synthesized IIP was used as a new support for solid phase extraction (SPE) of ruthenium from environmental samples before electrothermal atomic absorption spectrometric determination. Variables affecting the SPE process, such as pH, load and elution flow rates, as well as concentration and volume of the eluting solution, were evaluated. The optimized procedure consists of a sample loading (sample pH of 6.5 ± 0.5) through IIP-SPE columns containing 200mg of the synthesized IIP at a flow rate of 1.0 mL min(-1). Elution was performed by passing 0.3 mol L(-1) thiourea in 0.1 mol L(-1) HCl at a flow rate of 1.0 mL min(-1). For 10 mL of sample pre-concentration factor of 20 was achieved. The limit of detection of the method was 0.32 ng mL(-1), while the relative standard deviation for six replicated separation processes was 2.5%. Good selectivity of the synthesized material for Ru(III) ions against other transition metal ions assures efficient removal of matrix of analyzed samples (tap and river water, municipal and road sewages, and grass) by the proposed IIP-SPE procedure.