Analytical Sciences

Abstract − Analytical Sciences, 29(1), 147 (2013).

Extraction Behavior and Selective Separation of Lead(II) Using N,N-Dioctyldiglycol Amic Acid
Kojiro SHIMOJO,* Ayaka NAKAI,*,** Hiroyuki OKAMURA,*,*** Akira OHASHI,** and Hirochika NAGANAWA*
*Division of Chemistry for Nuclear Engineering, Nuclear Science and Engineering Directorate, Japan Atomic Energy Agency (JAEA), Tokai-mura, Ibaraki 319-1195, Japan
**College of Science, Ibaraki University, Mito, Ibaraki 310-8512, Japan
***Division of Material Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa 920-1192, Japan
Selective separation of lead ions (Pb2+) from aqueous solutions containing multiple divalent metal ions (Pb2+, Cu2+, Cd2+, Zn2+, Mn2+, Co2+, and Ni2+) was investigated using liquid–liquid extraction. N,N-Dioctyldiglycol amic acid (DODGAA) enabled quantitative extraction and efficient separation of Pb2+ from the metal ion mixture under mildly acidic conditions. Compared with conventional commercial extractants, DODGAA provided better extraction and excellent selectivity for Pb2+. The extraction of Pb2+ with DODGAA proceeded through a proton-exchange reaction and formed a 1:2 complex, Pb(DODGAA)2. The Pb2+ was readily stripped from the extracting phase under acidic conditions, and the organic solution with DODGAA could be recycled.