A mass spectrometer system can include an ion source, a vacuum chamber; a mass analyzer within the vacuum chamber, a transfer tube between the ion source and the vacuum chamber, a transfer tube heater, and a vacuum pump. The mass spectrometer system can be configured to reduce the pump speed of the vacuum pump in response to receiving a transfer tube swap instruction; lower the temperature of the transfer tube to below a first threshold; operating the vacuum pump at the reduced pump speed while the transfer tube is replaced with a second transfer tube; heating the second transfer tube to a temperature above a pump down temperature; and increasing the pump speed of the vacuum pump after the temperature of the second transfer tube exceeds a second threshold.

Methods and circuits for detecting an ion current in a mass spectrometer are described. A circuit and a method may involve converting, over a length of integration time, the ion current to a voltage ramp by an integrating circuit having a gain setting. The circuit and the method may also involve determining a slope of the voltage ramp. The circuit and the method may also involve determining a magnitude of the ion current based on the slope of the voltage ramp and the gain setting. The circuit and the method may further involves determining an out-of-range state based on the voltage ramp and adjusting the gain setting of the integrating circuit, or the length of integration time or both, in response to the determining of the out-of-range state.

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 P.sub.1 in the vicinity of the first RF ion guide and the length L.sub.1 of the first RF ion guide is in the range 10-100 mbar-cm and the product of the pressure P.sub.2 in the vicinity of the second RF ion guide and the length L.sub.2 of the second RF ion guide is in the range 0.05-0.3 mbar-cm.

The invention generally relates to systems and methods for performing multiple precursor, neutral loss and product ion scans in a single ion trap. In certain aspects, the invention provides systems including a mass spectrometer having a single ion trap, and a central processing unit (CPU), and storage coupled to the CPU for storing instructions that when executed by the CPU cause the system to apply at least one of the following ion scans to a single ion population in the single ion trap: multiple precursor ion scans, a plurality of segmented neutral loss scans, or multiple simultaneous neutral loss scans.

Methods and circuits for detecting an ion current in a mass spectrometer are described. A circuit and a method may involve converting, over a length of integration time, the ion current to a voltage ramp by an integrating circuit having a gain setting. The circuit and the method may also involve determining a slope of the voltage ramp. The circuit and the method may also involve determining a magnitude of the ion current based on the slope of the voltage ramp and the gain setting. The circuit and the method may further involves determining an out-of-range state based on the voltage ramp and adjusting the gain setting of the integrating circuit, or the length of integration time or both, in response to the determining of the out-of-range state.

The invention generally relates to systems and methods for separating ions at about or above atmospheric pressure. In certain embodiments, the invention provides systems that include an ionization source that generates ions and an ion trap. The ion trap is maintained at about or above atmospheric pressure and includes a plurality of electrodes and at least one inlet configured to receive a gas flow and at least one outlet. The system is configured such that a combination of a gas flow and one or more electric fields produced by the electrodes separates the ions based on mass-to-charge ratio and sends the separated ions through the at least one outlet of the ion trap.

The invention generally relates to sample analysis systems and methods of use thereof. In certain aspects, the invention provides a system for analyzing a sample that includes an ion generator configured to generate ions from a sample. The system additionally includes an ion separator configured to separate at or above atmospheric pressure the ions received from the ion generator without use of laminar flowing gas, and a detector that receives and detects the separated ions.

Devices, methods, computer-readable media, and systems for determining an identity of a food are disclosed. For example, a method may receive at least one property of at least one component in a sample of a food from an intra-oral device including a spectrometer, the at least one property obtained via the spectrometer, compares the at least one property to a plurality of food signatures, and determines the identity of the food based upon the comparing. In another example, a system may include an intra-oral device and a wireless device. The intra-oral device may include a spectrometer for measuring at least one property of at least one component in a sample of a food. The wireless device may include a processor for receiving the at least one property, comparing the at least one property to a plurality of food signatures, and determining the identity of the food based upon the comparing.

An analytical device includes: a regulator to which a gas storage container attached and which is held by a holder; a gas introduction chamber to which gas in the gas storage container is supplied through the regulator; and a movement mechanism that moves the holder so that the regulator moves between a measurement position and a non-measurement position.

A miniature mass spectrometer is disclosed comprising an atmospheric pressure ionisation source, 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. A first vacuum pump is arranged and adapted to pump the first vacuum chamber, wherein the first vacuum pump is arranged and adapted to maintain the first vacuum chamber at a pressure <10 mbar. A first RF ion guide is located within the first vacuum chamber and an ion detector is located in the third 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.