Asymmetric induction devices and systems and methods using them

Patent metadata

Field	Value
Publication number	US-10375811-B2
Application number	US-201715400129-A
Country	US
Kind code	B2
Filing date	Jan 6, 2017
Priority date	Mar 14, 2013
Publication date	Aug 6, 2019
Grant date	Aug 6, 2019

Abstract

Certain embodiments described herein are directed to devices, systems and methods that comprise asymmetric induction devices. In some instances, the device can include a plurality of plate electrodes which can be spaced asymmetrically or a plurality of coils which can be spaced asymmetrically.

First claim

The invention claimed is:

1. A device for generating a plasma in a torch body with a longitudinal axis along which a flow of gas is introduced during operation of the torch body, the device comprising a plurality of induction coils comprising at least three coils coupled to each other and forming an aperture configured to receive a portion of the torch body, in which the at least three coils comprise a first coil coupled to a second coil and a third coil coupled to the second coil to provide an induction coil winding configured to receive the torch body in the formed aperture, wherein longitudinal spacing along a longitudinal direction substantially parallel to the longitudinal axis of the torch body between at least two of the first coil, the second coil and the third coil is asymmetric in the longitudinal direction.

2. The device of claim 1 , further comprising a detector fluidically coupled to the torch body and configured to receive analyte species from the atomization source sustained in the torch body.

3. The device of claim 2 , in which the detector is selected from the group consisting of an optical excitation detector, an absorption detector and a mass spectrometer.

4. The device of claim 1 , in which longitudinal spacing between the first coil and the second coil is greater than longitudinal spacing between the second coil and the third coil, and in which the third coil is configured to be positioned closest to a terminus of the torch body.

5. The device of claim 1 , in which longitudinal spacing between the first coil and the second coil is less than longitudinal spacing between the second coil and the third coil, and in which the third coil is configured to be positioned closest to a terminus of the torch body.

6. The device of claim 1 , further comprising a radio frequency source electrically coupled to the device.

7. The device of claim 6 , in which the radio frequency source is configured to provide radio frequencies of about 1 MHz to about 1000 MHz at a power of about 10 Watts to about 10,000 Watts.

8. The device of claim 1 , comprising a first radio frequency source electrically coupled to at least the first coil of the device and a second radio frequency source electrically coupled to a coil different than the first coil of the device.

9. The device of claim 8 , in which each of the first radio frequency source and the second radio frequency source is configured to provide radio frequencies of about 1 MHz to about 1,000 MHz at a power of about 10 Watts to about 10,000 Watts.

10. The device of claim 1 , in which longitudinal spacing between the first coil and the second coil is greater than longitudinal spacing between the second coil and the third coil, in which the third coil is configured to be positioned closest to a terminus of the torch body, and in which longitudinal spacing between each of the first coil, the second coil and the third coil is selected to shift a maximum analyte signal to occur at a lower nebulization gas flow rate.

11. The device of claim 10 , in which the longitudinal spacing between the first coil and the second coil is about 4 mm and the longitudinal spacing between the second coil and the third coil is about 2 mm.

12. The device of claim 1 , in which longitudinal spacing between the first coil and the second coil is less than longitudinal spacing between the second coil and the third coil, in which the third coil is configured to be positioned closest to a terminus of the torch body, and in which longitudinal spacing between each of the first coil, the second coil and the third coil is selected to shift a maximum analyte signal to occur at a lower nebulization gas flow rate.

13. The device of claim 12 , in which the longitudinal spacing between the first coil and the second coil is about 2 mm and the longitudinal spacing between the second coil and the third coil is about 4 mm.

14. The device of claim 1 , in which the device comprises at least a fourth coil coupled to the third coil with at least two of the first coil, the second coil, the third coil and the fourth coil spaced differently in the longitudinal direction than a longitudinal spacing between two other coils.

15. The device of claim 14 , in which the device comprises at least a fifth coil coupled to the fourth coil, with at least two of the first coil, the second coil, the third coil, the fourth coil and the fifth coil spaced differently in the longitudinal direction than a longitudinal spacing between two other coils.

16. The device of claim 1 , further comprising a radio frequency source electrically coupled to the device, the radio frequency source comprising variable capacitors configured to permit adjustment of a plasma voltage with different coil spacing.

17. The device of claim 1 , further comprising a sampling interface fluidically coupled to the torch body.

18. The device of claim 17 , in which the sampling interface comprises a sampling cone.

19. The device of claim 1 , which longitudinal spacing between the first coil and the second coil is less than longitudinal spacing between the second coil and the third coil, in which the third coil is configured to be positioned closest to a terminus of the torch body, and in which longitudinal spacing between each of the first coil, the second coil and the third coil is selected to shift a maximum interfering oxide signal to occur at a higher nebulization gas flow rate.

20. The device of claim 1 , in which longitudinal spacing between the first coil and the second coil is greater than longitudinal spacing between the second coil and the third coil, in which the third coil is configured to be positioned closest to a terminus of the torch body, and in which longitudinal spacing between each of the first coil, the second coil and the third coil is selected to shift a maximum interfering oxide signal to occur at a higher nebulization gas flow rate.

Assignees

• Perkinelmer Health Sci Inc

Inventors

• Morrisroe Peter J

Classifications

• H05H1/0037

  by spectrometry · CPC title

• H05H1/30 Primary

  using applied electromagnetic fields, e.g. high frequency or microwave energy (H05H1/28 takes precedence) · CPC title

• H01J49/04

  Arrangements for introducing or extracting samples to be analysed, e.g. vacuum locks; Arrangements for external adjustment of electron- or ion-optical components · CPC title