Patent RU-2207555-C2 (RU)
Title: Flow-through conductometric cell for liquid chromatography
Inventor: VLADYKIN G B
IPC: G01N27/02
Filed: 2001-07-24
Granted: 2003-06-27
Abstract: FIELD: physico-chemical methods of analytical chemistry, chromatographic analysis with conductometric registration of component composition of liquid flow at outlet of chromatographic column. SUBSTANCE: flow-through conductometric cell for liquid chromatography has body, inlet and outlet conduits, holes and pipe unions to feed and discharge liquid, through axial passage made in body along major axis of cell, mobile and immobile electrodes electrically insulated one from another, uniaxially arranged in through axial passage along major axis of cell with clearance between them, having working surfaces in the form of two parallel planes. Clearance between electrodes can be changed by means of translation of mobile electrode without rotation along major axis of cell. Main space of cell is located in clearance between working surfaces of electrodes, sealing elements to make operational space of cell and electric contacts to supply operation potential difference to electrodes tight are confined in body. Mobile electrode has inlet conduit with inlet hole arranged in center of working surface of mobile electrode. Body of cell is produced from metal and carries outlet pipe union and outlet conduit linked on one side to outlet pipe union and terminating on other side in outlet hole in body of cell abutting on sealing element of mobile electrode from beneath, placed on internal surface of through axial passage in body of cell above working surface of immobile electrode, at minimal distance from it. Sealing element of immobile electrode borders on plane of position of working surface of immobile electrode. Limiting bushing made of dielectric material with fixed clearance between its internal surface and mobile electrode and without clearance with immobile electrode is sealed in through axial passage in body of cell. There is clearance between working surfaces of electrodes located inside bushing. Fixed clearances between mobile electrode and internal surface of through axial passage in body of cell and limiting bushing in space between sealing elements of electrodes form additional space and are equal in value. Cross-section area of outlet conduit of body of cell is by an order of magnitude smaller than cross-section area of fixed clearance between mobile electrode and internal surface of through axial passage in body of cell and limiting bushing. Distance between working surface of immobile electrode and outlet hole in body of cell is determined by additional space and hydraulic resistance of fixed clearance between mobile electrode and internal surface of through axial passage in body of cell and limiting bushing. Additional space does not exceed in value two magnitudes of main space in clearance between working surfaces of electrodes and hydraulic resistance of fixed clearance between mobile electrode, internal surface of through axial passage in body of cell and limiting bushing is at least by one order of magnitude smaller than hydraulic resistance of outlet conduit in body of cell. EFFECT: increased accuracy of chromatographic analysis, operational reliability and simplified design of cell. 1 dwg