US 6,718,817 B1Granted

Sample injection device for gas chromatography

AssigneeChung-Shan Institute of Science and Technology

InventorsHsien-Wen Ko, Wun-Shung Lee, Fu-Hsiang Wang, Jon-Wey Chu

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Abstract

The present invention herein relates to a sample injection device for micro gas chromatograph is assembled from five layers of thin plates and membrane. The first layer serves as cover plate and interfacial connection to outside columns. The second layer is fabricated with a sample channel and a carrier gas inlet split into an analytical channel and a reference gas channel, and two valve seats. The third layer is a flexible diaphragm for valve actuation. The fourth layer is fabricated with a pressurizing gas inlet hole and pressurizing channel leading to the diaphragms of valve seats. The fifth layer serves as another cover plate. An external solenoid valve is used to control the processes of sampling and injection. The channels and valve seats on each layer plate can be fabricated through several well-developed fabrication techniques such as photolithographic, LIGA processes or precision micro machining. All five layers are properly aligned and bonded by adhesives.

Claims21

Dependent claims

A sample injection device for gas chromatography, comprising:

a gas sample channel on a side of second layer to connect to inlet valve, outlet valve and injection valve to inject a fixed portion of sample to an analytical column;
an inlet valve connecting to inlet at a end of said gas sample channel to introduce sample at normally open condition and closed upon pressurization during sample injection;
an outlet valve connecting to outlet at a end of said gas sample channel to release excess sample at normally open condition and closed upon pressurization during sample injection;
an injection valve having its seat on one side of a fourth layer to connect near outlet end of said gas sample channel to be closed at normal condition and opened upon pressurization to inject a fixed portion of sample to an analytical column;
a carrier gas port on a second layer for same side of said gas sample channel to split into an analytical gas channel and a reference gas channel, wherein said analytical gas channel connected to reference capillary column and said reference gas channel connected to analytical capillary column, said analytical gas channel and said reference gas channel leading to a gaseous detector and being much narrower than said gas sample channel;
a solenoid valve connecting a carrier gas tank and said gas sample channel being activated open to pressurize the said gas sample channel and close the said inlet valve and outlet valve and open the said injection valve.

3 more elements

Dependencies are inferred from the claim text.