Separation of Cd(II), Pb(II), Zn(II), and Cu(II) by High Performance Centrifugal Partition Chromatography with Di‐2‐methylnonylphosphoric Acid

Abstract

The separation of heavy metal ions such as Cd(II), Pb(II), Zn(II), and Cu(II) has been investigated by high performance centrifugal partition chromatography (HPCPC) employing 0.12 M di‐2‐methylnonylphosphoric acid (DMNPA)/heptane as a stationary phase. The liquid–liquid extraction for the above four metal ions was examined with 0.10 M tartrate, citrate, and trichloroacetate media. Based on the different half extraction values obtained, the HPCPC parameters were optimized. Among organic acid buffers as the mobile phase tested, tartrate was found to be the most suitable for separating Cu(II) and Cd(II), citrate for Pb(II) and Zn(II), and trichloroacetate for Cd(II), Pb(II), and Zn(II). A two step elution method using two kinds of mobile phases (pH different) could be well applied to the separation of the four kinds of metal ions in mixture. The HPCPC system was operated with 2,136 partition channels, at a rotation speed of 800 rpm, and at a flow rate of 1.0 cm³/min.

Keywords:

• Separation
• High performance centrifugal partition chromatography
• Heavy metal ions
• Di‐2‐methylnonylphosphoric acid
• Organic acids