Method and apparatus for injecting liquid into a capillary tube

US5358613A · kind A · utility

Assignee

• Hewlett-Packard Company, L.P. · US

Inventors

• Werner Schneider · Erbach, DE
• Klaus Witt · Keltern, DE

Key dates

• Filing date: Dec 27, 1993
• Grant date: Oct 25, 1994
• Expiry date: Dec 27, 2013

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N2030/285
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

In a method and a corresponding apparatus for injecting liquid from a vial into a capillary tube, in particular in capillary electrophoresis, a source of overpressure and a source of underpressure are connectable to the vial for applying overpressure or underpressure in the space above the liquid. During an injection, the pressure is continuously varied in a controlled way by corresponding control of the pressure sources, for example by controlling associated valves. The pressure is first gradually increased and then gradually decreased. The actual pressure variation during an injection is measured by a pressure sensor and used by a controller to control the durations of the time intervals during which overpressure or underpressure are applied such that a desired amount of liquid is introduced into the capillary.