Immobilized metal affinity composite membrane based on cellulose for separation of biopolymers

A new iminodiacetic acid (IDA) type chelating membrane based on composite matrix formed by covalently coupling the polyglycidyl methacrylate to cotton cellulose fiber was developed. The study focused on the optimal conditions for the preparation of the membrane and the reaction of the chelating agent (iminodiacetic acid, IDA) with the matrix. The physical properties of the chelating membrane were tested by electron micrography and BET surface area instrument. The relationship between flow-rate and backpressure was almost linear. Adsorption isotherm of protein on Cu2+ - IDA membrane was determined by batch experiments. The dissociation constants and the maximum adsorption capacity were obtained. The results of affinity purification of human serum albumin and bovine liver catalase on membrane are comparable with those on gel chromatography presented in literature. The separations performed on the membrane chromatography, however, were 3-5 times faster than those on gel chromatography. The immobilized metal composite membrane was also successfully used in HPLC for rapid analysis of protein. Thus, the composite membrane reported here, with low backpressure, low cost and long service-life, is quite suitable for rapid and large scale affinity purification and HPLC analysis of biopolymers.