Removal and pre-concentration of phenolic species onto β-cyclodextrin modified poly(hydroxyethylmethacrylate–ethyleneglycoldimethacrylate) microbeads

Poly(Hydroxyethylmethacrylate–Ethyleneglycoldimethacrylate), poly(HEMA–EGDMA), microbeads with 150–200 μm in size, was prepared by suspension polymerization. β-cyclodextrin was modified onto the polymeric microbeads using glutaraldahyde activation in an acidic medium at pH = 2.5. FT-IR and TGA were used for the characterization of modified polymers and the determination of the nature of the interaction between phenolic compounds and the modified polymeric microbeads. Plain and β-cyclodextrin modified microbeads were used in adsorption–desorption studies of phenolic species in single solution. Adsorption capacities of the phenolic species onto the plain microbeads were found to be 28.2, 17.0, 14.3, 9.8, and 1.92 mg/g polymer for o-chloro phenol, p-nitro phenol, p-chloro phenol, o-nitro phenol, and phenol, respectively. However, for β-cyclodextrin modified microbeads, adsorption capacity of phenolic species was determined as 274, 365, 128, 182, and 87 mg/g for phenol, o-nitro phenol, p-nitro phenol, o-chloro phenol, and p-chloro phenol, respectively. Desorption ratio for the phenolic species was more than 90%, except for o-nitro phenol. Detection limits of the phenolic species were improved at least 500-fold for UV–Vis spectrophotometric detection, after the pre-concentration of all phenolic species used in this study. Adsorption time for the phenolic species onto β-cyclodextrin-modified poly(HEMA–EGDMA) microbeads was found to be reasonable short (10–60 min) and suitable for the applications. Also, synthesized microbeads were useful for the repeated use for the removal and pre-concentration of phenolic species.