Issue 13, 2011

Ultrasensitive CE for heavy metal ions using the variations in the chemical structures formed from new octadentate fluorescent probes and cationic polymers

Abstract

Novel fluorescent probes have been developed for the ultratrace detection of heavy metal ions by capillary electrophoresis using laser-induced fluorescence detection. Based on a molecular design, the probes are composed of an octadentate chelating moiety, a macrocyclic DOTA (tetraazacyclododecanetetraacetic acid) and an acyclic DTPA (diethylenetriaminepentaacetic acid) frame, a spacer and a fluorophore (fluorescein). These were chosen on the basis of their ability to form kinetically inert and highly emissive complexes, and to prevent a quenching effect even with heavy and paramagnetic metal ions. Addition of a cationic polymer, polybrene, in the separation buffer provided high resolution and simultaneous detection of Ca2+, Mg2+, Cu2+, Zn2+, Ni2+, Co2+, Mn2+, Cd2+ and Pb2+. The direct fluorescence detection of these metal ions with high sensitivity at lower ppt levels, typically 2–7 × 10−11 M (potentially sub-ppt), was successfully achieved. While separation of anionic compounds using a counter cation (“Ion Association (IA)” mode) is typically controlled by the ion association equilibrium constants, Kass, it was found that differences in the mobilities, µep(IAC), of the ion association complexes formed between the probe complexes and counter cations are the driving forces for separation in this new method. This suggests that each of the polybrene–probe complexes has different chemical structures among metal ions, which were able to be determined by CD spectra in this investigation. This novel separation mode was termed the “Ion Association Complex (IAC)” mode, distinct from the IA mode.

Graphical abstract: Ultrasensitive CE for heavy metal ions using the variations in the chemical structures formed from new octadentate fluorescent probes and cationic polymers

Supplementary files

Article information

Article type
Paper
Submitted
07 Oct 2010
Accepted
21 Feb 2011
First published
21 Mar 2011

Analyst, 2011,136, 2697-2705

Ultrasensitive CE for heavy metal ions using the variations in the chemical structures formed from new octadentate fluorescent probes and cationic polymers

S. Saito, Y. Nakano, A. Hikichi, R. Suzuki, K. Yoshimoto, M. Maeda, M. Aoyama and M. Shibukawa, Analyst, 2011, 136, 2697 DOI: 10.1039/C0AN00777C

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements