Sample injector for high pressure liquid chromatography

A method of injecting a sample into a chromatography column for chromatographic analysis, comprising the steps of:

• providing a flow of a running buffer to the chromatography column;
• shutting off the flow of running buffer;
• applying a voltage to a sample injector having a common junction with the chromatography column to cause a sample to flow into the common junction;
• and
• starting the flow of running buffer to apply a pressure to drive the sample contained in the common junction into and through the chromatography column.

An apparatus for the high pressure injection of a sample into a chromatography column, comprising:

• a substrate fabricated to define a microchannel system disposed thereon, the microchannel system comprising, in combination,
• a source of high pressure joined at a common junction to the inlet of the chromatography column;
• and
• a sample injector joined to the to the common junction, said sample injector comprising at least two elements combined in a series arrangement and connected to a common power supply, wherein each element comprises a container having an inlet end and an outlet end, the container filled with a dielectric material forming a porous bed therein.