The invention relates to an ion source for generating ions for calibrating a mass spectrometer and methods for calibrating the mass spectrometer using the generated ions. The ion source includes a container used for containing a sample; an ionization device used for ionizing a sample by plasma discharge to generate ions for calibrating the mass spectrometer, where the ionization device operates at atmospheric pressure; and a delivery device for delivering the sample from the container to the ionization device. The method includes generating ions by plasma discharge at atmospheric pressure using a sample; inputting at least one part of the ions into the mass spectrometer to obtain a mass spectrogram; and calibrating the mass spectrometer according to the mass spectrogram.

The invention relates to the detection of non-metabolized vitamin D. In a particular aspect, the invention relates to methods for detecting underivatized non-metabolized vitamin D by mass spectrometry.

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.

A mass spectrometry method comprising steps of generating an ion beam from an ion source; directing the ion beam into a collision cell; introducing into the collision cell through a gas inlet on the collision cell a charge-neutral analyte gas or reaction gas; ionizing the analyte gas or reaction gas in the collision cell by means of collisions between the analyte gas or reaction gas and the ion beam; transmitting ions from the ionized analyte gas or reaction gas from the collision cell into a mass analyzer; and mass analyzing the transmitted ions of the ionized analyte or reaction gas. The methods can be applied in isotope ratio mass spectrometry to determine the isotope abundance or isotope ratio of a reaction gas used in mass shift reactions between the gas and sample ions, to determine a corrected isotope abundance or ratio of the sample ions.

An ion molecule reactor for generating analyte ions from analytes comprises: a) a reaction volume in which reagent ions can interact with the analytes in order to form analyte ions; b) at least one analyte inlet for introducing the analytes along an inlet path into the reaction volume whereby, preferably, the inlet path runs essentially along at least a first section of the predefined transit path in the reaction volume; c) at least one reagent ion source and/or at least one reagent ion inlet for providing reagent ions into the reaction volume; d) optionally, at least one ion guide comprising an electrode arrangement which is configured for producing an alternating electrical, magnetic and/or electromagnetic field, that allows for guiding the reagent ions and/or the analyte ions at least along a section of the predefined transit path, preferably along the whole transit path, through the reaction volume. There is also provided a sampler comprising one or more chambers, wherein each chamber is configured for receiving an individual sample and comprises an inlet and an outlet, such that a gaseous fluid flow can pass through each of the chambers.

The present disclosure provides a sample desorption ionization device and analysis method for a mass spectrometer. The device has a first gas pressure region and a second gas pressure region lower than the first gas pressure region. The device includes: a heating desorption device, carrying a sample and heating the sample, an analyte in the sample is desorbed from the sample under a heating action and then enters the first gas pressure region; a vacuum interface component, connected with the first gas pressure region and the second gas pressure region, and causing the analyte to enter the second gas pressure region from the first gas pressure region under the drive of a gas flow; and a soft ionization source, converting gas molecules in the second gas pressure region into activated gas molecules, the analyte entering the second gas pressure region realizes soft ionization after interacting with the activated gas molecules.

Methods and apparatus for monitoring air samples for the presence of the explosive TATP are disclosed. A preferred approach employs proton transfer reaction mass spectrometry PTR-MS). The system may be operated continuously on a real time or near real time basis. A delivery tube of specific dimensions and materials is employed to introduce the sample into the ionization chamber which in turn generates the ions which are delivered to the mass spectrometer for determining the m/z values. The system may employ a plurality of ionization chambers to reduce the amount of false negative identifiers. A multiple inlet ion funnel may be employed to combine the ions from each of the ionization chambers. Chemical ionization may be employed. A validation module may be employed to reduce the amount of false positive identifiers.

Disclosed herein is a method of determining an endogenous analyte released from skin of a subject. The endogenous analyte is selected from the group consisting of an amino acid, a hormone, a neurotransmitter and combinations thereof. The method includes the steps of obtaining a sample which contains the endogenous analyte from the skin of the subject using a probe; desorbing the endogenous analyte from the sample; subjecting the desorbed endogenous analyte to an ionization reaction with a charged reactive species generated by an ionization device, so as to produce an ionized endogenous analyte; and determining the ionized endogenous analyte with a mass spectrometer.

The invention relates to the detection of DHA and EPA. In a particular aspect, the invention relates to methods for detecting DHA and EPA by mass spectrometry and kits for carrying out such methods.

An ion source comprising a chamber and an electron collector is described. In one configuration, the chamber comprises a sample inlet and an ion outlet. The chamber may also include an electron inlet configured to receive electrons from an electron source. The electron collector can be arranged in opposition to the electron inlet. The chamber can be configured to direct an electron beam from the electron source along a path with the chamber transverse to a path between the gas inlet and the ion outlet. The chamber may comprise an ion guide that includes a guide axis offset from an axis of the ion outlet.