Single electrode conductivity detection for electrophoretic separation systems

Various types of detectors have been utilised in electrophoretic separation systems, but conductivity detection provides the obvious choice for detect ing ionic substances. This paper describes a new design of conductivity det ector utilising a single, on column, sensing electrode. This new design is seen as offering the twin advantages of much higher resolution, than has pr eviously been possible, and simple construction. The detector has been eval uated using separations of sodium and potassium in capillary isotachophoret ic and miniaturised planar polymer isotachophoretic separation systems. Goo d linearity has been found and the limit of detection of sodium calculated to be 0.43 mM. (C) 1999 Elsevier Science B.V. All rights reserved.