title: Extraction behavior and selective separation of lead(II) using N,N-dioctyldiglycol amic acid.
abstract: Selective separation of lead ions (Pb(2+)) from aqueous solutions containing multiple divalent metal ions (Pb(2+), Cu(2+), Cd(2+), Zn(2+), Mn(2+), Co(2+), and Ni(2+)) was investigated using liquid-liquid extraction.  N,N-Dioctyldiglycol amic acid (DODGAA) enabled quantitative extraction and efficient separation of Pb(2+) from the metal ion mixture under mildly acidic conditions.  Compared with conventional commercial extractants, DODGAA provided better extraction and excellent selectivity for Pb(2+).  The extraction of Pb(2+) with DODGAA proceeded through a proton-exchange reaction and formed a 1:2 complex, Pb(DODGAA)(2).  The Pb(2+) was readily stripped from the extracting phase under acidic conditions, and the organic solution with DODGAA could be recycled.
authors.affiliation: Division of Chemistry for Nuclear Engineering, Nuclear Science and Engineering Directorate, Japan Atomic Energy Agency (JAEA), Tokai-mura, Ibaraki, Japan. shimojo.kojiro@jaea.go.jp
authors.forename: Kojiro
authors.initials: K
authors.lastname: Shimojo
authors.forename: Ayaka
authors.initials: A
authors.lastname: Nakai
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Okamura
authors.forename: Akira
authors.initials: A
authors.lastname: Ohashi
authors.forename: Hirochika
authors.initials: H
authors.lastname: Naganawa
mesh_terms: D002413:Cations, Divalent / Q000302:isolation & purification; D006016:Glycolates / Q000138:chemical synthesis / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007854:Lead / Q000302:isolation & purification*; D059625:Liquid-Liquid Extraction / Q000295:instrumentation / Q000379:methods*; D015394:Molecular Structure; D009943:Organophosphorus Compounds / Q000737:chemistry; D012996:Solutions
chemical_list: D002413:Cations, Divalent; D006016:Glycolates; C581676:N,N-dioctyldiglycol amic acid; D009943:Organophosphorus Compounds; D012996:Solutions; D007854:Lead