Efficient and selective extraction of iodide through a liquid membrane

A new type of efficient and selective extraction method for iodide across a n organic liquid membrane is proposed for the separation of iodide from som e cations and anions, especially from other halide ions. Iodide is oxidized to iodine by nitrite ion in acidic media and the resultant iodine can be e xtracted into a chloroform phase. The iodine is automatically treated with hydroxide solution, disproportionates to ions and is back-extracted into an aqueous phase (receiving phase). The extraction efficiency is approximatel y 91% for the first 50 min. This transfer is monitored by a simple spectrop hotometric procedure. The influence of other halides and some adverse ions on the transportation of iodide was studied. (C) 2001 Elsevier Science B.V. All rights reserved.