FABRICATION OF ELECTROCHEMICAL DETECTOR FOR CAPILLARY ELECTROPHORESIS

摘要

An improved electrochemical detector (10) for use in capillary zone electrophoresis having a working electrode of the order of magnitude of 32 microns in diameter inserted in a separation capillary (12) of the order of 50 microns in diameter is fabricated as follows: the separator capillary is bonded to a rigid collar (18) and an electrical joint through a fracture (26) is defined in the separator capillary. The collar (18) is telescopically disposed within a first guide capillary (20) approximately 1.2 millimeters outer diameter. The first guide capillary is then telescopically inserted into an outer sleeve capillary (38) of approximately 1.25 millimeters in inner diameter. Similarly a working electrode (40) is aspirated into a drawn down second guide tube (42) of approximately 1.2 millimeters in outer diameter. A mercury pool (76) is disposed in the second guide tube (42) and a contacting wire (48) is electrically coupled to the mercury pool and hence to the working electrode. The second guide tube is then disposed within the sleeve capillary (38) with the two guide tubes moved toward each other so that the centralized working electrode (40) is telescopically inserted within the separation capillary. The assembly is sealed and thus serves as a rugged electrochemical detector which can be intergrally fabricated on the end of the separation column.