Leland Stanford Junior University

Takao Tsuda

Richard Neil Zare

Jonathan V Sweedler

An apparatus and method useful for sample injection in capillary electrophoresis is disclosed. The apparatus comprises an interface device with capillary and tubing inserted therein. Sample is injected through the tubing into the interface and is thereafter introduced into the capillary column in which the capillary electrophoresis separation is performed. The apparatus introduces precise amounts of sample into the capillary and the interface can be designed for split flow or direct sample introduction. Employing the interface device, the injection method permits samples to be introduced into capillaries without the need to disengage or to alter the electric field. The method is suited for adaptation with autosamplers or auto-injection systems.

Capillary electrophoresis injection device and method

An elongated or rectangular cross-section capillary is disclosed for use in capillary electrophoresis using optical detection. With rectangular capillaries, heat is efficiently dissipated which permits large volume applications in capillary electrophoresis. In addition, the increase in cell pathlength produces significant improvements in absorbance detection sensitivity. This advantage is also important for laser-induced fluorescence, optical rotation, and other pathlength-dependent detection schemes. Because flat walls produce less optical distortion than circular capillary walls, rectangular capillaries are particularly useful when parameters such as refractive index, photodeflection, direct visualization or particle counting are used for detection. Capillary electrophoresis employing rectangular capillaries allows for two-dimensional separations.

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Palo Alto, CA, United States of America

Takao Tsuda