Four types of chitosan beads

carboxylic chitosan (SUC-CS)

benzoyl chitosan(BEN-CS)

polyethyleneiminated ehitosan (PEI-CS) and quatemaminated chitosan (QA-CS) were prepared using the wet phase-inversion method and chemical modification with the chemicals of succinic anhydride

benzoic anhydride

polyethyleneimine and 3-chloro-2-hydroxypropyltrimethyl ammonium chloride． Carboxyl

aromatic acyI

polyethyleneimine and quaternary ammonium groups were induced to chitosan chains

and their structure was characterized by FTIR spectra．The adsorption ability of the chemically modified ehitosan resins to nine kinds of diuretics was investigated．The results show that

compared to the unmodified chitosan

the benzoyl chltosan has higher affinity and capacity to almost all the diuretics due to the hydrophobie interaction between chitosan and dmg molecule

while the earboxyl chitosan has higher binding affinity only to the basic diuretics．The polyethyleneiminated chitosan has 48％～209％higher capacity to the acidic diuretics due to the increased concentration of amino groups on its chain．The adsorption ability of quatemaminated chitosan for the diuretics with carboxyl group is greatly improved

especially for the bumetanide

which is above 2 times higher than the unmodified one because of the strong interaction of ion exchange．