Multipole ion guide ion trap mass spectrometry with MS/MSN analysis
View Patent ↗A method includes directing ions from an atmospheric pressure ion source to a first ion guide; directing ions in the first ion guide to a second ion guide, the second ion guide being a multipole ion guide extending along an axis; periodically directing ions along the axis; receiving at least some of the ions in a time-of-flight analyzer; accelerating the ions in the time-of-flight mass analyzer orthogonal to the axis; and detecting the accelerated ions.
1. A method, comprising:
directing ions from an atmospheric pressure ion source to a first ion guide;
directing ions in the first ion guide to a second ion guide, the second ion guide being a multipole ion guide extending along an axis;
periodically directing ions along the axis;
receiving at least some of the ions in a time-of-flight mass analyzer;
accelerating the ions in the time-of-flight mass analyzer orthogonal to the axis; and
detecting the accelerated ions, wherein
the second ion guide is positioned between the first ion guide and the time-of-flight mass analyzer.
2. The method of claim 1 , wherein the ions are continuously directed from the atmospheric pressure ion source to the first ion guide.
3. The method of claim 1 , wherein the ions are periodically directed to the time-of-flight mass analyzer by trapping ions within one of the ion guides.
4. The method of claim 3 , wherein the ions are trapped in the second ion guide.
5. The method of claim 1 , further comprising fragmenting ions from the atmospheric pressure ion source and directing the fragmented ions to the time-of-flight mass analyzer.
6. The method of claim 5 , wherein the ions are fragmented in the first ion guide.
7. The method of claim 1 , further comprising mass filtering ions from the atmospheric pressure ion source before directing the ions to the time-of-flight mass analyzer.
8. The method of claim 7 , wherein the ions are mass filtered using the second ion guide.
9. The method of claim 1 , wherein the first ion guide is located entirely within a first vacuum chamber and the second ion guide is located entirely within a second vacuum chamber portioned from the first vacuum chamber.
10. The method of claim 9 , further comprising maintaining a background gas pressure in the second vacuum chamber below 1×10 −3 ton.
11. The method of claim 10 , further comprising maintaining a background gas pressure in the first vacuum chamber between 5×10 −4 ton and 1×10 −2 torr.