Enhanced determination of glucose by microchip electrophoresis with pulsed amperometric detection

The present report describes a new analysis strategy for microchip capillary electrophoresis with pulsed amperometric detection and its application to the determination of glucose. The addition of sodium dodecyl sulfate (SDS) to the mobile phase and detection reservoir stabilized flow rates and enhanced the detection signal for glucose. A higher pH (compared to the running buffer) was used at the waste reservoir in order to improve the detection performance while maintaining good separations. To our knowledge, this is the first report describing the use of post-column pH modification using microchip electrophoresis. Under optimum conditions, a linear relationship between the peak current and the concentration of glucose was found between 10^-2–10^-5 M, with a limit-of-detection of 1.2 (mu)M. In addition, the separation of glucosamine and glucose was performed at pH 7.1 while the detection was performed at pH 11 to demonstrate the ability to use postcolumn pH modification.