Abstract: Adsorbents for bilirubin were prepared by immobilizing amino group on crosslinking poly(2-hydroxyethyl methacrylate)(PHEMA) resins. The effects of adsorption temperature, ion strength, bilirubin concentration and human serum albumin on the adsorption properties for bilirubin were studied. It was shown that, this kind of adsorbent had a good adsorption efficiency and high adsorption capacity, and the adsorption performances of resins immobilizing hexanediamine and protonized hexanediamine were better than others. When adsorption temperature rose from 20 ℃ to 45 ℃, the adsorption percentage of resins immobilizing hexanediamine and protonized hexanediamine for bilirubin increased slightly, while that of resins immobilizing triethylenetetraamine increased below 37 ℃ and decreased above 37 ℃, which could be due to the stronger interaction between hexanediamine and bilirubin than that between triethylenetetraamine and bilirubin. The adsorption percentage decreased when ion strength increased. With the increase of the concentration of bilirubin in solution, the adsorption percentage decreased while the adsorption capacity increased. When the concentration of bilirubin was 750 mg/L, the adsorption percentage of resins bearing hexanediamine was near 80% and that of resins bearing protonized hexanediamine was over 90%, and the adsorption capacity were 29.84 mg/g and 34.60 mg/g respectively. Resins immobilizing hexanediamine and protonized hexanediamine could also adsorb bilirubin in the presence of albumin. The adsorption of bilirubin by the PHEMA adsorbents containing amino groups could be attributed to the interaction between amino groups on adsorbents and carboxyl groups in bilirubin and also the hydrophobic interaction and hydrogen bonds.

Key words: Bilirubin, Amino group, Poly(2-hydroxyethyl methacrylate), Adsorption