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US 9,852,894 B2Granted
Compact mass spectrometer
AssigneeMicromass UK Limited
InventorsDavid Gordon, Daniel James Kenny
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AssigneeMicromass UK Limited
InventorsDavid Gordon, Daniel James Kenny
Estimating the term…
A miniature mass spectrometer is disclosed comprising an atmospheric pressure ionization source and a first vacuum chamber having an atmospheric pressure sampling orifice or capillary, a second vacuum chamber located downstream of the first vacuum chamber and a third vacuum chamber located downstream of the second vacuum chamber. An ion detector is located in the third vacuum chamber. A first RF ion guide is located within the first vacuum chamber and a second RF ion guide is located within the second vacuum chamber. The ion path length from the atmospheric pressure sampling orifice or capillary to an ion detecting surface of the ion detector is ≦400 mm. The mass spectrometer further comprises a tandem quadrupole mass analyzer, a 3D ion trap mass analyzer, a 2D or linear ion trap mass analyzer, a Time of Flight mass analyzer, a quadrupole-Time of Flight mass analyzer or an electrostatic mass analyzer arranged in the third vacuum chamber. The product of the pressure P1 in the vicinity of the first RF ion guide and the length L1 of the first RF ion guide is in the range 10-100 mbar-cm and the product of the pressure P2 in the vicinity of the second RF ion guide and the length L2 of the second RF ion guide is in the range 0.05-0.3 mbar-cm.
A miniature mass spectrometer comprising:
A miniature mass spectrometer comprising:
A method of mass spectrometry comprising:
A method of mass spectrometry comprising:
Dependencies are inferred from the claim text.
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From the US filing history. Foreign family members aren’t listed.
Particle spectrometers or separator tubes: miniaturised spectrometers, e.g. having smaller than usual scale, integrated conventional components
Methods for using particle spectrometers: step by step routines describing the use of the apparatus
Details: ion sources; Ion guns
Using particle bombardment, e.g. ionisation chambers: using chemical ionisation
About 9 years 1 month of term left · ends 19 Nov 2035 (estimated)
The present invention relates to a mass spectrometer and a method of mass spectrometry. The preferred embodiment relates to a compact or miniature mass spectrometer in conjunction with an Atmospheric Pressure Ionisation (“API”) ion source.
Conventional mass analysers are normally unable to operate at or near atmospheric pressure and so are located within a vacuum chamber that is evacuated to a low pressure. Most commercial mass analysers operate at a vacuum level of 1×10−4 mbar or lower.
Mass spectrometers with Atmospheric Pressure Ionisation (“API”) ion sources utilise a sampling orifice or capillary in or near the ion source to allow the ions that are created at atmospheric pressure (“AP”) to be admitted into the vacuum chamber containing the mass analyser.
Various embodiments of the present invention will now be described, by way of example only, and with reference to the accompanying drawings in which:
FIG. 1 shows a plot of the relative ion transmission as a function of the diameter of an orifice in an atmospheric sampling cone;
FIG. 2 shows a plot of the relative ion transmission as a function of the diameter of a gas limiting orifice situated between the first two regions of differential pumping of a mass spectrometer;
A preferred embodiment of the present invention will now be described. The preferred embodiment relates to a compact or miniature mass spectrometer which preferably maintains a level of sensitivity similar to current commercial full size mass spectrometers but which is substantially smaller (<0.05 m3 c.f.>0.15 m3 for a conventional full size instrument), lighter (<30 kg c.f.>70 kg) and less expensive.
The preferred miniature mass spectrometer utilises a small backing vacuum pump and a small turbomolecular vacuum pump with considerably lower pumping speeds (<70 L/s c.f.>300 L/s for a full size turbomolecular vacuum pump and <5 m3/h c.f.>30 m3/h for the backing vacuum pump) than a conventional full size mass spectrometer and which consequently consumes considerably less electricity and generates considerably less heat and noise than a conventional full size mass spectrometer.
The preferred mass spectrometer is preferably used for real time on-line analysis of samples separated using high pressure or ultra-high pressure liquid chromatography (HPLC/UHPLC). As such, the sensitivity of the mass spectrometer is commonly described in terms of the signal-to-noise of the mass spectral intensity obtained for a given quantity of a specified molecule as it elutes from the liquid chromatography (LC) system. For example, the sensitivity specification for a conventional full size mass spectrometer comprising a single quadrupole mass spectrometer is that a 1 pg on column injection (5 μL of 0.2 pg/μL) of Reserpine should give a chromatographic signal-to-noise (S:N) for m/z 609 greater than 120:1.