Selective Liquid–Liquid Extraction of Mercuric Ions by Octyl Methane Sulfonamide

Abstract

N-octyl methane sulfonamide (OMSA) has been demonstrated to be a very efficient reagent for selective extraction of Hg(II) ions, from aqueous solutions. The extraction bases on rapid reaction of OMSA with Hg(II) ions yielding mono and disulfonamido mercury compounds in ordinary conditions. Solubility of OMSA and its mercury compounds in 2-ethyl hexanol provide a clear-cut phase separation in the extraction. The solution of OMSA in 2-ethyl hexanol (0.4 mol L 21 ) is able to extract 82.2% of mercuric-acetate (0.4 mol L 21 ) in non-buffered conditions. Although the process depends on the nature of accompanying anions, the distribution coefficient is reasonably high (kd $ 1.27) even in the presence of chloride ions. The extraction is strictly selective and the presence of Cd(II), Zn(II), Pb(II) do not bring any interference.