Portable capillary electrophoresis instrument with amperometric, potentiometric and conductometric detection

The prototype of a field-portable battery-powered capillary electrophoresis instrument described here includes a high voltage supply capable of delivering the standard 30 kV at both polarities. The instrument has dimensions of 340 mm X 175 mm X 175 mm (wXhXd) and a weight of 7.5 kg. Data acquisition is carried out with a portable laptop or palmtop computer. Electrochemical detection was chosen as the straightforward signal transduction methods are relatively easily implemented. For robustness, the amperometric and potentiometric detection modes are carried out in a fixed wall-jet cell without decoupler. Both methods rely on the electrophoretic ground electrode as reference and counter electrode. For conductometric detection the only recently reported contactless version was implemented. The availability of the three complementary electrochemical detection methods allows for great versatility, which includes the ability to determine inorganic cations and anions as well as many organic species of interest. (C)2001 Elsevier Science B.V. All rights reserved.