Monosize and non-porous p(HEMA-co-MMA) microparticles designed as dye- andmetal-chelate affinity sorbents

Congo red was immobilised onto monosize and non-porous poly(2-hydroxyethylm ethacrylate-co-methylmethacrylate) [p(HEMA-co-MMA)] copolymer microparticle s (4.0 mu m in diameter). Then Fe(III) ions were complexed by chelation wit h the immobilised congo red molecules. Different amounts of Fe(III) ions we re loaded on the dye-derived microparticles by changing the concentration o f Fe(III) ions and pH of the reaction medium. Congo red-derived and Fe(III) -complexed microparticles were used in the adsorption of glucose oxidase, c atalase, lysozyme and bovine serum albumin. The maximum adsorption capaciti es of these microparticles were determined by changing pH and the concentra tion of the proteins in the adsorption medium. Their adsorption behavior ca n be described at least approximately with the Langmuir equation. Glucose o xidase, catalase, lysozyme and bovine serum albumin adsorption capacities o f the Fe(III) complexed microparticles (165.1, 135.2, 67.6 and 44.5 mg g(-1 )) were higher than those of the congo red-immobilised microparticles (125. 9, 94.2, 35.8 and 21.2 mg g(-1), respectively). The non-specific adsorption of the proteins on the p(HEMA-co-MMA) microparticles was negligible. The r esulting dye- and metal-chelate affinity microparticles have excellent reus ability and long term storage stability. (C) 2000 Elsevier Science B.V. All rights reserved.