Integrated monolithic microfabricated electrospray and liquid chromatography system and method

• US 6,417,510 B2
• Filed: 12/21/2000
• Issued: 07/09/2002
• Est. Priority Date: 09/17/1998
• Status: Expired due to Term

• Current Assignee: Rheonix, Inc.
• Original Assignee: Kionix Incorporated (ROHM Co., Ltd.)
• Inventors: Davis, Timothy J., Moon, James E., Galvin, Gregory J.
• Primary Examiner(s): Lee, John R.
• Assistant Examiner(s): Vanore, David A.
• Application Number:
  US09/747,085
• Publication Number:
  US 20010007350A1
• Time in Patent Office: 565 Days
• Field of Search: 250/288, 250/306, 156/242, 204/600, 210/198.2, 210/243, 210/656, 210/748
• US Class Current: 250/288
• 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 29/49002 Electrical device making
• CPC Class Codes: Y10T 436/25375 Liberation or purification of sample or separation of material from a sample [e.g., filtering, centrifuging, etc.]
• CPC Class Codes: Y10T 436/255 including use of a solid sorbent, semipermeable membrane, or liquid extraction

Abstract

A mass spectrometric analysis system is disclosed. The system preferably includes a microfabricated electrospray device formed at least in part by reactive-ion etching and a mass spectrometer which includes a sampling orifice. The electrospray device preferably includes at least one nozzle integrated in a substrate for ejecting at least one analyte at the mass spectrometer and at least one electrode for applying at least one electric potential for generating and controlling an electric field at the nozzle to direct the analyte ejected from the nozzle into the sampling orifice. In a preferred embodiment, the substrate is silicon. In another preferred embodiment, the system also includes an array of nozzles positioned such that an electrospray ejected from each nozzle sprays directly into the mass spectrometer sampling orifice with no translational movement of the electrospray device after initial positioning. In a third preferred embodiment, the system includes controlling circuitry which is integrated on the substrate. In yet another embodiment, the system also includes an external means of translating the microfabricated electrospray device from one position to another position. The external means positions the microfabricated device with respect to the mass spectrometer sampling orifice such that a specified nozzle is positioned to eject its electrospray from the specified nozzle into the sampling orifice. The external means also preferably positions any of the nozzles in any sequence or pattern to eject, in turn, their individual electrosprays into the sampling orifice.

Claims

1. A mass spectrometric analysis system, comprising:

a microfabricated electrospray device formed at least in part by reactive-ion etching;

a mass spectrometer, said mass spectrometer including a sampling orifice;

said electrospray device including at least one nozzle integrated in a substrate for ejecting at least one analyte at said mass spectrometer;

at least one electrode on said electrospray device for applying at least one electric potential for generating and controlling an electric field at said at least one nozzle to direct said at least one analyte ejected from said at least one nozzle into said sampling orifice; and

controlling circuitry for said mass spectrometric analysis system, said circuitry being integrated on said substrate.

2. The system of claim 1, wherein said substrate is silicon.

3. The system of claim 1, further comprising an array of nozzles wherein each of said nozzles is positioned such that an electrospray ejected from each nozzle sprays directly into said mass spectrometer sampling orifice with no translational movement of said electrospray device after initial positioning.

4. The system of claim 1, further comprising:

an external means of translating said microfabricated electrospray device from one position to another position, wherein

said external means positions said microfabricated device with respect to said sampling orifice of said mass spectrometer such that a specified nozzle is positioned to eject its electrospray from said specified nozzle into said sampling orifice, and

said external means positions any of said nozzles in any sequence or pattern to eject, in turn, their individual electrosprays into said sampling orifice.