Synthesis of ion imprinted polymer for separation and preconcentration of iron (III)

Abstract

Solid phase extraction is a preferable separation technique since it offers many advantages such as simple, good stability and can be regenerated over time. Due to presence of contaminant in the matrix, pre-concentration must be conducted using selective sorbent. Ion imprinted polymer (IIP) has remarkable selectivity and affinity towards the ion target due to its specific cavity during the imprinting process. In this study, Fe(III)-IIP was successfully synthesized by applying iron (template) with gallic acid (ligand) in acetonitrile and copolymerized using methyl methacrylate (functional monomer) and ethylene glycol dimethyl acrylate (EGDMA) as a crosslinker in the presence of azo-bis-isobutyronitrile (AIBN) as initiator. Fe(III)-IIP was characterized using FTIR, SEM-EDX, and TGA. Optimization of Fe(III)-IIP synthesis was carried out by varying the mole ratio of monomer to template (1:1, 2:1, and 3:1). Adsorption test exhibited the optimum ratio of 2:1 with the maximum adsorption capacity of 122.264 mg/g at pH 5 for 60 minutes contact time. The adsorption mechanism followed Freundlich equation with R2 0.9781. Relative selectivity of Fe(III)/Cr(III) and Fe(III)/Ag(I) were 3.41 and 0.707, respectively. The IIP was further tested for preconcentration of Fe(III) in lake water sample and obtained the % recovery value 102.02 %, 97.04 %, dan 96.61 %. IIP was successfully applied for iron preconcentration in water samples.