Copper wire amperometric detector for capillary electrophoresis

Abstract

Abstract The use of a copper wire amperometric detector for capillary electrophoresis is reported. Detection is accomplished by use of a porous glass joint, which allows amperometric detection at a copper wire electrode inserted in the end of the capillary. An anodic current is produced by a change in the copper oxide film solubility, resulting from complexation of copper ions with certain analytes at the electrode surface. This copper/copper oxide electrode has been used to detect nonelectroactive native amino acids and dipeptides. Subfemtomole detection limits in picoliter injection volumes have been obtained without solute derivatization. In addition, simultaneous analysis of nonelectroactive amino acids and electroactive catecholamines has been demonstrated.