PURPOSE: To remove endotoxin up to extremely low concn. with high treatment efficiency by bringing an endotoxin-containing solution into contact with a chitosan membrane.
CONSTITUTION: An acidic aqueous chitosan solution is cast on a fabric using polyethylene glycol (PEG) with an mol.wt. of 10,000 or more as a dope solution and this fabric is immersed in a basic aqueous solution to coagulate chitosan and sufficiently washed with water to obtain a chitosan film. The amount of an acid to be used is pref. made as little as possible and set to an amount min. to dissolve chitosan. In general, an acid is added in an amount of 0.2 - 5 times by wt. of chitosan. When an endotoxin adsorbing solution is passed, differential pressure is not almost generated within an adapted passing speed range and an industrially advantageous result is obtained. Further, by adjusting pH, the chitosan solution can be adapted to all of protein-containing solutions stable at pH of pI or less and endotoxin in a solution can be selectively adsorbed and removed.
ENOMOTO MIKIJI
HASHIMOTO MASANORI
