Integrated monolithic microfabricated electrospray and liquid chromatography system and method

• US 6,563,111 B1
• Filed: 10/31/2000
• Issued: 05/13/2003
• Est. Priority Date: 09/17/1998
• Status: Expired due to Term

• Current Assignee: Rheonix, Inc.
• Original Assignee: Advion BioSciences Incorporated
• Inventors: Schultz, Gary A., Corso, Thomas N., Lowes, Stephen, Davis, Timothy J., Moon, James E., Galvin, Gregory J.
• Primary Examiner(s): Anderson, Bruce
• Assistant Examiner(s): Wells, Nikita
• Application Number:
  US09/703,246
• Time in Patent Office: 924 Days
• Field of Search: 250/288, 250/282, 250/281
• US Class Current: 250/288
• CPC Class Codes: G01N 2030/6013 interfaces to detectors
• CPC Class Codes: G01N 30/6095 Micromachined or nanomachined, e.g. micro- or nanosize
• CPC Class Codes: G01N 30/7266 by electric field, e.g. electrospray
• CPC Class Codes: H01J 49/0018 Microminiaturised spectrometers, e.g. chip-integrated devices, Micro-Electro-Mechanical Systems [MEMS]
• CPC Class Codes: H01J 49/167 Capillaries and nozzles specially adapted therefor; electrostatic spraying per se B05B5/00
• CPC Class Codes: Y10T 436/24 Nuclear magnetic resonance, electron spin resonance or other spin effects or mass spectrometry
• CPC Class Codes: Y10T 436/2575 Volumetric liquid transfer

Abstract

An electrospray device, a liquid chromatography device and an electrospray-liquid chromatography system are disclosed. The electrospray device comprises a substrate defining a channel between an entrance orifice on an injection surface and an exit orifice on an ejection surface, a nozzle defined by a portion recessed from the ejection surface surrounding the exit orifice, and an electrode for application of an electric potential to the substrate to optimize and generate an electrospray; and, optionally, additional electrode(s) to further modify the electrospray. The liquid chromatography device comprises a separation substrate defining an introduction channel between an entrance orifice and a reservoir and a separation channel between the reservoir and an exit orifice, the separation channel being populated with separation posts perpendicular to the fluid flow; a cover substrate bonded to the separation substrate to enclose the reservoir and the separation channel adjacent the cover substrate; and, optionally, electrode(s) for application of a electric potential to the fluid. The exit orifice of the liquid chromatography device may be homogeneously interfaced with the entrance orifice of the electrospray device to form an integrated single system. An array of multiple systems may be fabricated in a single monolithic chip for rapid sequential fluid processing and generation of electrospray for subsequent analysis, such as by positioning the exit orifices of the electrospray devices near the sampling orifice of a mass spectrometer.

Claims

1. A method for generating an electrospray of a fluid, comprising:

providing a monolithic electrospray substrate having an injection side on an opposite planar side from an ejection surface, the monolithic substrate defining;

an entrance orifice on the injection side,

a nozzle on the ejection surface,

a channel extending continuously through the monolithic substrate communicating with the entrance orifice and the nozzle, and

a region surrounding the nozzle recessed from the ejection surface;

introducing a fluid into the channel through the entrance orifice;

providing a first electrode in electrical contact with the fluid;

applying a first potential voltage to the fluid;

positioning the nozzle adjacent to an extracting electrode; and

ejecting the fluid in the form of an electrospray from the channel through the nozzle by applying or holding the extracting electrode at a second potential voltage different from the first potential voltage.

2. The method of claim 1, further comprising:

providing a second electrode in electrical contact with the monolithic substrate; and

applying a third potential voltage to said second electrode, different from said first potential voltage.