Mass spectrometer and nozzle member
The mass spectrometer includes an ionization unit that ionizes a sample; a nozzle unit having an inflow port that is connected to the ionization unit by a flow pipe and through which the ionized sample flows, and an outflow port from which the sample flowing in flows out; a vacuum chamber that is evacuated by vacuum evacuation means and into which the sample flows from the nozzle unit; a mass analysis unit that is located downstream of a flow of the sample relative to the vacuum chamber and that selects ions from the sample; and an ion detection unit that detects the ions selected by the mass analysis unit, wherein a division portion that divides a flow of the sample is provided inside the nozzle unit, and the division portion has a tapered projection whose diameter decreases toward the outflow port.
1. A mass spectrometer comprising:
an ionization unit that ionizes a sample;
a nozzle unit having an inflow port that is connected to the ionization unit by a flow pipe and through which the ionized sample flows, and an outflow port from which the sample flowing in flows out;
a vacuum chamber that is evacuated by vacuum evacuation means and into which the sample flows from the nozzle unit;
a mass analysis unit that is located downstream of a flow of the sample relative to the vacuum chamber and that selects ions from the sample; and
an ion detection unit that detects the ions selected by the mass analysis unit, wherein
a division portion that divides a flow of the sample is provided inside the nozzle unit, and
the division portion has a tapered projection whose diameter decreases toward the outflow port.
2. The mass spectrometer according to claim 1 , wherein
the projection has a conical shape.
3. The mass spectrometer according to claim 2 , wherein
a central axis of the projection and a central axis of the outflow port substantially coincide with each other.
4. The mass spectrometer according to claim 1 , wherein
the division portion has a substantially circular cross section.
5. The mass spectrometer according to claim 1 , wherein
a support portion which supports the division portion is provided on an inner wall of the nozzle unit at a position closer to the inflow port than the outflow port.
6. The mass spectrometer according to claim 1 , wherein
the division portion is supported by a plurality of support portions.
7. The mass spectrometer according to claim 4 , wherein
the division portion is supported by an annular support portion that has a boundary with an outer periphery of the division portion and an outer periphery of an inner wall of the nozzle unit, the annular support portion being provided with a plurality of holes.
8. The mass spectrometer according to claim 1 , wherein
a ratio P1/P2 between a pressure P1 in the flow pipe and a pressure P2 in the vacuum chamber is 50 times or more.
9. The mass spectrometer according to claim 1 , wherein
the mass analysis unit includes n sets of rod-shaped electrodes to which a DC voltage Un and an AC voltage Vn RF COS (Ω RF +RF) are applied where n is an integer of 2 or more.
10. The mass spectrometer according to claim 2 , wherein
a vertex of the projection is located closer to the inflow port than an opening end of the outflow port.
11. The mass spectrometer according to claim 1 , further comprising:
an outer portion having an opening surrounding the division portion, the opening whose diameter decreases from the inflow port toward the outflow port having a tapered shape.
12. The mass spectrometer according to claim 1 , wherein
the division portion has an end closer to the inflow port, the end projecting relative to the inflow port.
13. A nozzle member used in a mass spectrometer, wherein
the nozzle member has an inflow port into which an ionized sample flows and an outflow port from which the sample flowing in flows out, and a division portion that divides a flow of the sample is provided inside the nozzle member, and
the division portion has a taper-shaped projection whose diameter decreases toward the outflow port.
14. A mass spectrometer comprising:
an ionization unit that ionizes a sample;
a nozzle unit having an inflow port that is connected to the ionization unit by a flow pipe and through which the ionized sample flows, and an outflow port from which the sample flowing in flows out;
a vacuum chamber that is evacuated by vacuum evacuation means and into which the sample flows from the nozzle unit;
a mass analysis unit that is located downstream of a flow of the sample relative to the vacuum chamber and that selects ions from the sample; and
an ion detection unit that detects the ions selected by the mass analysis unit, wherein
a division portion that divides a flow of the sample is provided inside the nozzle unit, and
the division portion causes the divided flow of the sample to cross and flow into the vacuum chamber.