イミノ二メチルホスホン酸型キトサン樹脂の合成と微量金属の捕集挙動

A chitosan-based resin possessing the iminodi(methylphosphonic acid) moiety (IDP-type chitosan resin) was synthesized by using cross-linked chitosan as a base material. The adsorption behavior of trace metal ions on the IDP-type chitosan resin was systematically investigated using a mini-column (1 ml of the resin) packed with the resin. The concentrations of metal ions in the effluents were measured by ICP-MS and ICP-AES. The resin could adsorb four metals, such as In(III), Sn(II), Th(IV), and U(VI), by almost 100% over a wide pH range (1∼7). Uranium(VI) and thorium could not be eluted with nitric acid and hydrochloric acid (1∼6 M); other metal ions were easily and readily eluted with 1 M nitric acid. The IDP-type chitosan resin synthesized in this work can be applied to the separation of U(VI) and Th(IV) from other metal ions.