eCite Digital Repository

Highly sensitive indirect photometric detection of cations by capillary electrophoresis with the cationic dye chrysoidine


Johns, CA and Macka, M and Haddad, PR, Highly sensitive indirect photometric detection of cations by capillary electrophoresis with the cationic dye chrysoidine, Journal of Chromatography A, 997, (1-2) pp. 87-94. ISSN 0021-9673 (2003) [Refereed Article]

Restricted - Request a copy

Copyright Statement

The definitive version is available at

Official URL:

DOI: doi:10.1016/S0021-9673(03)00062-1


The cationic dye, chrysoidine, has been used for the first time as a probe for the indirect photometric detection of cations. The dye has been used as a probe at concentrations of 5 mM, which is roughly an order of magnitude higher than for other cationic dyes used previously for the same purpose, in order to minimise electromigrational dispersion. Baseline instability was minimised by a combination of coating the capillary with poly(ethyleneimine), addition of a neutral polymer to the electrolyte, and the application of a small amount (20 mbar) of hydrodynamic pressure during the separation. Separation of a mixture containing alkali metals, alkaline earths, transition metals and lanthanides was achieved by the addition of 2-hydroxyisobutyric and lactic acid as complexing agents. Excellent peak shapes were observed over a wide range of analyte mobilities due to the moderate mobility of the probe. The high absorptivity (26 733 l mol−1 cm−1) provided by chrysoidine in comparison with typically used, less absorbing probes, was reflected in limits of detection which were typically less than 0.5 μM. These are amongst the lowest reported using hydrodynamic injection without the use of large volume stacking methods. The use of 2-hydroxyisobutyric and lactic acids as complexing agents at pH values close to their pKa values provided suitable buffering which was highlighted by very good reproducibility of migration time, corrected peak area and peak height.

Item Details

Item Type:Refereed Article
Keywords:Dyes, Chrysoidine; Inorganic cations; Organic acids
Research Division:Chemical Sciences
Research Group:Analytical chemistry
Research Field:Separation science
Objective Division:Expanding Knowledge
Objective Group:Expanding knowledge
Objective Field:Expanding knowledge in the chemical sciences
UTAS Author:Johns, CA (Dr Cameron Johns)
UTAS Author:Macka, M (Professor Mirek Macka)
UTAS Author:Haddad, PR (Professor Paul Haddad)
ID Code:27509
Year Published:2003
Web of Science® Times Cited:28
Deposited By:Chemistry
Deposited On:2003-08-01
Last Modified:2010-02-05

Repository Staff Only: item control page