US 11,721,536 B2
Mass spectrometer
Manabu Ueda, Kyoto (JP); Tomohito Nakano, Kyoto (JP); and Yuki Tanaka, Kyoto (JP)
Assigned to SHIMADZU CORPORATION, Kyoto (JP)
Appl. No. 17/291,824
Filed by SHIMADZU CORPORATION, Kyoto (JP)
PCT Filed Nov. 29, 2018, PCT No. PCT/JP2018/044042
§ 371(c)(1), (2) Date May 6, 2021,
PCT Pub. No. WO2020/110264, PCT Pub. Date Jun. 4, 2020.
Prior Publication US 2021/0391164 A1, Dec. 16, 2021
Int. Cl. H01J 49/04 (2006.01); H01J 49/06 (2006.01); H01J 49/16 (2006.01); H01J 49/24 (2006.01)
CPC H01J 49/0431 (2013.01) [H01J 49/063 (2013.01); H01J 49/165 (2013.01); H01J 49/24 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A mass spectrometer comprising:
an atmospheric pressure ion source configured to ionize a component in a liquid sample;
a first intermediate vacuum chamber disposed in a next stage of the atmospheric pressure ion source and evacuated by a first vacuum pump;
an ion guide disposed in the first intermediate vacuum chamber and configured to transport ions while converging them by an action of a high-frequency electric field;
a first opening for introducing ions generated in the atmospheric pressure ion source into the first intermediate vacuum chamber;
an analysis chamber having a high vacuum disposed in a stage behind the first intermediate vacuum chamber and evacuated by a second vacuum pump or both the second vacuum pump and the first vacuum pump;
a mass separator disposed in the analysis chamber and configured to separate an ion in accordance with its mass-to-charge ratio; and
an ion detector disposed in the analysis chamber and configured to detect an ion separated by the mass separator, wherein
an opening area of the first opening is equal to or greater than 0.071 mm2, a product of an opening area of the first opening and pressure in the first intermediate vacuum chamber is within a range of 15 to 40 mm2·Pa, and an evacuation speed of the first vacuum pump is equal to or less than 15 m3/Hr.