Discharge chambers and ionization devices, methods and systems using them
Certain configurations of plasma discharge chambers and plasma ionization sources comprising a plasma discharge chamber are described. In some examples, the discharge chamber comprises a conductive area and is configured to sustain a plasma discharge within the discharge chamber. In other examples, the discharge chamber comprises at least one inlet configured to receive a plasma gas and at least one outlet configured to provide ionized analyte from the discharge chamber. Systems and methods using the discharge chambers are also described.
1. A method comprising ionizing an analyte by:
introducing the analyte into a plasma discharge sustained within a discharge chamber comprising a first electrode configured to couple to a power source, wherein the discharge chamber comprises at least one inlet to receive a plasma gas and at least one outlet to provide ionized analyte from the discharge chamber, wherein the at least one inlet is coupled to the at least one outlet through a bend to remove interfering species from the ionized analyte, wherein the at least one inlet is present in a first region of the discharge chamber and the at least one outlet is outside the first region of the discharge chamber, and wherein the plasma discharge is sustained within the discharge chamber by providing a voltage to the first electrode in the presence of a plasma gas introduced into the discharge chamber through the at least one inlet of the discharge chamber, wherein the introduced analyte is ionized using a first plasma gas; and
permitting the ionized analyte to exit the discharge chamber through the at least one outlet prior to introduction of a second analyte into the discharge chamber.
2. The method of claim 1 , further comprising introducing the second analyte into the discharge chamber to ionize the introduced second analyte using a second plasma gas different from the first plasma gas.
3. The method of claim 1 , further comprising ionizing the introduced analyte using a first voltage provided to the first electrode, and, after permitting exit of the ionized analyte from the discharge chamber, introducing the second analyte into the discharge chamber to ionize the introduced second analyte using a second voltage provided to the first electrode, wherein the second voltage is different from the first voltage.
4. The method of claim 1 , further comprising coupling the discharge chamber to a second discharge chamber, wherein the second discharge chamber is electrically coupled to a second electrode, wherein the second discharge chamber comprises at least one inlet, and at least one outlet, and wherein a plasma discharge is sustained within the second discharge chamber by providing a voltage to the second electrode in the presence of a plasma gas.
5. The method of claim 4 , further comprising configuring the second discharge chamber with at least one bend between the at least one inlet of the second discharge chamber and the at least one outlet of the second discharge chamber.
6. The method of claim 1 , further comprising sustaining the plasma discharge in the discharge chamber without any inductive coupling.
7. An ionization source comprising:
a first discharge chamber configured to receive a sample from a sample introduction device, the first discharge chamber comprising:
a first electrode,
at least one inlet to receive a plasma gas, and
at least one outlet to provide ionized analyte from the first discharge chamber,
wherein the at least one inlet is present in a first region of the first discharge chamber and the at least one outlet is outside the first region of the first discharge chamber, and wherein the first discharge chamber is configured to sustain a first plasma discharge in the presence of a plasma gas introduced into the first discharge chamber through the at least one inlet of the first discharge chamber; and
a second discharge chamber arranged parallel to the first discharge chamber and configured to receive the sample from the sample introduction device, the second discharge chamber comprising:
a second electrode,
at least one inlet to receive a plasma gas, and
at least one outlet to provide ionized analyte from the second discharge chamber,
wherein the at least one inlet of the second discharge chamber is present in a first region of the second discharge chamber and the at least one outlet is outside the first region of the second discharge chamber, and wherein the second discharge chamber is configured to sustain a second plasma discharge in the presence of a plasma gas introduced into the second discharge chamber.
8. The ionization source of claim 7 , wherein the first discharge chamber is a straight chamber.
9. The ionization source of claim 8 , wherein the at least one inlet of the second discharge chamber is coupled to the at least one outlet of the second discharge chamber through a bend.
10. The ionization source of claim 7 , wherein the at least one inlet of the first discharge chamber is coupled to the at least one outlet of the first discharge chamber through a bend.
11. The ionization source of claim 10 , wherein the first discharge chamber further comprises a second region coupled to the first region and a third region coupled to the second region, wherein the at least one outlet of the first discharge chamber is in the third region and the bend is in the second region.
12. The ionization source of claim 10 , wherein the at least one inlet of the second discharge chamber is coupled to the at least one outlet of the second discharge chamber through a bend.
13. The ionization source of claim 12 , wherein the second discharge chamber further comprises a second region coupled to the first region and a third region coupled to the second region, wherein the at least one outlet of the second discharge chamber is in the third region and the bend is in the second region.
14. The ionization source of claim 12 , wherein the bend of the second discharge chamber comprises a different shape than the bend of the first discharge chamber.
15. The ionization source of claim 7 , wherein the first electrode is positioned within the at least one inlet of the first discharge chamber.
16. The ionization source of claim 15 , wherein the second electrode is positioned within the at least one inlet of the second discharge chamber.
17. The ionization source of claim 7 , wherein the first discharge chamber and the second discharge chamber are configured to receive a first plasma gas.
18. The ionization source of claim 7 , wherein the first discharge chamber and the second discharge chamber are configured to receive a different plasma gas.
19. The ionization source of claim 7 , further comprising a valve configured to switch flow of the sample between the first discharge chamber and the second discharge chamber.
20. The ionization source of claim 7 , further comprising a valve configured to provide flow of the sample to both of the first discharge chamber and the second discharge chamber.