Issue 3, 2020

Evaluation of dual electrode configurations for microchip electrophoresis used for voltammetric characterization of electroactive species

Abstract

Microchip electrophoresis coupled with amperometric detection is more popular than voltammetric detection due to the lower limits of detection that can be achieved. However, voltammetry provides additional information about the redox properties of the analyte that can be used for peak identification. In this paper, two dual electrode configurations for microchip electrophoresis are described and evaluated for obtaining voltammetric information using amperometry. The dual-series electrode configuration was first evaluated to generate current ratios in a single run by applying two different potentials to the working electrodes placed perpendicular to the separation channel. However, it was found that it is difficult to obtain realistic current ratios with this configuration, primarily due to the relative placement of electrodes with respect to the channel end of the simple-t microchip. Correction factors were needed to obtain current ratios similar to those that would be obtained for sequential injections at two different potentials using a single electrode. A second approach using a dual-channel chip with two parallel electrodes was then developed and evaluated for obtaining voltammetric identification. The newly developed microchip permitted the injection of same amount of sample into two unique separation channels, each with an electrode at a different detection potential. Migration times and current ratios for several biologically important molecules and potential interferences including nitrite, tyrosine, hydrogen peroxide, and azide were obtained and compared to the responses obtained for analytes found in macrophage cell lysates.

Graphical abstract: Evaluation of dual electrode configurations for microchip electrophoresis used for voltammetric characterization of electroactive species

Article information

Article type
Paper
Submitted
23 oct. 2019
Accepted
21 nov. 2019
First published
25 nov. 2019

Analyst, 2020,145, 865-872

Author version available

Evaluation of dual electrode configurations for microchip electrophoresis used for voltammetric characterization of electroactive species

D. B. Gunasekara, M. B. Wijesinghe, P. Pichetsurnthorn and S. M. Lunte, Analyst, 2020, 145, 865 DOI: 10.1039/C9AN02112D

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