EP-4740236-A1 - APPARATUSES AND METHODS FOR ION INJECTION IN MASS SPECTROMETRY

Abstract

In some examples, an apparatus may include an ion injector including an ion injector entrance and an ion injector exit, and a capillary cap disposed at the ion injector exit. The capillary cap may include a capillary cap exit opening that is shaped and sized to reduce gas turbulence after the ion injector exit and improve ion signal stability.

Inventors

• ZEKAVAT, Behrooz
• BERTSCH, JAMES L.

Assignees

• Agilent Technologies, Inc.

Dates

Publication Date

20260513

Application Date

20240618

Claims (20)

1. 1 . An apparatus comprising: an ion injector including an ion injector entrance and an ion injector exit; and a capillary cap disposed at the ion injector exit, wherein the capillary cap includes a capillary cap exit opening that is shaped and sized to reduce gas turbulence after the ion injector exit and improve ion signal stability.
2. 2. The apparatus according to claim 1 , wherein the capillary cap includes a concave area on an opposite side of an exit face of the capillary cap.
3. 3. The apparatus according to claim 1 , wherein the capillary cap exit opening includes a rectangular slot shape.
4. 4. The apparatus according to claim 3, wherein the rectangular slot shape includes curved portions.
5. 5. The apparatus according to claim 1 , wherein the capillary cap exit opening includes a cross slot shape.
6. 6. The apparatus according to claim 1 , wherein the capillary cap exit opening includes a star slot shape.
7. 7. The apparatus according to claim 1 , wherein the capillary cap includes a muzzle brake configuration including a circular capillary cap exit opening and elongated slots along a side wall of the capillary cap.
8. 8. An apparatus comprising: a capillary cap disposable at an ion injector exit of an ion injector that includes an ion injector entrance and the ion injector exit, wherein the capillary cap includes a capillary cap exit opening that is shaped and sized to reduce gas turbulence after the ion injector exit and improve ion signal stability.
9. 9. The apparatus according to claim 8, wherein the capillary cap exit opening includes a rectangular slot shape.
10. 10. The apparatus according to claim 9, wherein the rectangular slot shape includes curved portions.
11. 11 . The apparatus according to claim 8, wherein the capillary cap exit opening includes a cross slot shape.
12. 12. The apparatus according to claim 8, wherein the capillary cap exit opening includes a star slot shape.
13. 13. The apparatus according to claim 8, wherein the capillary cap includes a muzzle brake configuration including a circular capillary cap exit opening and elongated slots along a side wall of the capillary cap.
14. 14. The apparatus according to claim 8, wherein the capillary cap includes a concave area on an opposite side of an exit face of the capillary cap.
15. 15. A method comprising: attaching a capillary cap to an ion injector exit of an ion injector including an ion injector entrance and the ion injector exit, wherein the capillary cap includes a capillary cap exit opening that is shaped and sized to reduce gas turbulence after the ion injector exit and improve ion signal stability.
16. 16. The method according to claim 15, wherein the capillary cap exit opening includes a rectangular slot shape.
17. 17. The method according to claim 15, wherein the capillary cap exit opening includes a smaller width compared to a bore diameter of a bore of the ion injector.
18. 18. The method according to claim 15, wherein the capillary cap exit opening is radially offset relative to a central longitudinal axis of a bore of the ion injector.
19. 19. The method according to claim 15, wherein the capillary cap exit opening includes a cross slot shape.
20. 20. The method according to claim 15, wherein the capillary cap includes a muzzle brake configuration including a circular capillary cap exit opening and elongated slots along a side wall of the capillary cap.

Description

APPARATUSES AND METHODS FOR ION INJECTION IN MASS SPECTROMETRY BACKGROUND [0001] In some cases, ionization techniques in mass spectrometry (MS) operate at atmospheric pressure. In order to detect and measure mass-to-charge ratios of the ionized species with atmospheric pressure (AP) ion sources, ions generated at atmospheric pressure may be transported from atmospheric pressure to a vacuum region of a MS system. In some cases, the MS system may generally include an ion injector, an electrodynamic ion funnel, and ion desolvation components. BRIEF DESCRIPTION OF DRAWINGS [0002] Features of the present disclosure are illustrated by way of example and not limited in the following figure(s), in which like numerals indicate like elements, in which: [0003] Figure 1 illustrates an atmospheric pressure to vacuum interface, in accordance with an example of the present disclosure; [0004] Figure 2 illustrates a singlebore resistive glass capillary (hereinafter also referred to as “ion injector”), in accordance with an example of the present disclosure; [0005] Figure 3 illustrates a round capillary cap and a slot exit capillary cap, in accordance with an example of the present disclosure; [0006] Figure 4 illustrates examples of slot, cross, star, and muzzle-brake shaped exit capillary caps, in accordance with an example of the present disclosure; [0007] Figure 5 illustrates various views of a slot exit capillary cap, in accordance with an example of the present disclosure; [0008] Figure 6 illustrates a cross section of a first part of the muzzle-brake shaped exit capillary cap, in accordance with an example of the present disclosure; [0009] Figure 7 illustrates various views of a second part of the muzzle-brake shaped exit capillary cap, in accordance with an example of the present disclosure; [0010] Figure 8 illustrates various views including cross sectional views of an ion injector with an entrance round bore and slot exit capillary cap, in accordance with an example of the present disclosure; [0011] Figure 9 illustrates a various views including a cross sectional view of an ion injector with an entrance round bore and a muzzle exit capillary cap and an entrance cap, in accordance with an example of the present disclosure; [0012] Figure 10 illustrates multiple reaction ion monitoring (MRM) ion signal stability, without application of a smoothing function to the ion signal, in accordance with an example of the present disclosure; [0013] Figure 11 A illustrates a cross section of the slot exit capillary cap of Figure 5 and an ion injector together with an ion funnel and ion desolvation components including an atmospheric pressure to vacuum interface, in accordance with an example of the present disclosure; [0014] Figure 11 B illustrates another example of a cross section of the slot cap of Figure 5 including an entrance cap and ion desolvation components, in accordance with an example of the present disclosure; [0015] Figure 12 illustrates cross sectional areas of singlebore (SB) capillaries (hereinafter also referred to as “ion injectors”) and various exit cap shapes sorted based on the cross sectional area, in accordance with an example of the present disclosure; [0016] Figure 13 illustrates an ion funnel pressure with various exit cap shapes and sizes, and reduction in ion funnel pressure as an indication of gas flow restriction, in accordance with an example of the present disclosure; [0017] Figure 14 illustrates a principal component analysis (PCA) score plot obtained from ion signal relative standard deviation (RSD) analysis of various rotation angles of a slot exit capillary cap relative to an ion injector axis, in accordance with an example of the present disclosure; [0018] Figure 15 illustrates a PCA score plot obtained from ion signal RSD analysis of various inlet configurations, in accordance with an example of the present disclosure; and [0019] Figure 16 illustrates liquid chromatography-mass spectrometry/mass spectrometry (LC/MS/MS) MRM chromatographic peak area versus RSD obtained for a mixture of pesticides, in accordance with an example of the present disclosure. DETAILED DESCRIPTION [0020] For simplicity and illustrative purposes, the present disclosure is described by referring mainly to examples. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. It will be readily apparent however, that the present disclosure may be practiced without limitation to these specific details. In other instances, some methods and structures have not been described in detail so as not to unnecessarily obscure the present disclosure. [0021] Throughout the present disclosure, the terms "a" and "an" are intended to denote at least one of a particular element. As used herein, the term "includes" means includes but not limited to, the term "including" means including but not limited to. The term "based on" means based at least in part