A mass spectrometer includes: an ion source; a collision cell into which a predetermined gas is introduced, for allowing an ion generated in the ion source to be in contact with the predetermined gas; and a quadruple mass filter for performing mass spectrometry on the ion ejected from the collision cell. The mass spectrometer further includes: an inlet electrode provided at an ion injection port through which the ion is incident in the collision cell; a voltage generator for applying a direct-current voltage to the inlet electrode; and a voltage controller and a controller for controlling the voltage generator to apply, to the inlet electrode, a direct-current voltage with a polarity same as a polarity of an unnecessary ion generated in the ion source, during at least a part of a standby period of time in which no analysis-target ion is analyzed.

An input lens is provided which has a large acceptance solid angle for electrons. The input lens is for use in an electron spectrometer and disposed between an electron source producing electrons and an electron analyzer in the electron spectrometer. The input lens has a reference electrode at a reference potential, a slit, first through nth electrodes, where n is an integer equal to or greater than three, arranged between the reference electrode and the slit, and a second mesh attached to the first electrode. The first through nth electrodes are arranged in this order along an optical axis. The second mesh is at a potential higher than the reference potential.

A constructed unit is fixed to a base by means of a plurality of support posts while being spaced from the base. The constructed unit includes an orthogonal acceleration unit. An incidence regulator unit is fixed to the base by a pair of support posts while being spaced from the base and the constructed unit. The incidence regulator unit includes, among others, a pair of blades that define a slit, and heaters for heating the pair of blades.

A method of analysis using mass spectrometry and/or ion mobility spectrometry is disclosed comprising: (a) using a first device to generate smoke, aerosol or vapour from a target in vitro or ex vivo cell population; (b) mass analysing and/or ion mobility analysing said smoke, aerosol or vapour, or ions derived therefrom, in order to obtain spectrometric data; and (c) analysing said spectrometric data in order to identify and/or characterise said target cell population or one or more cells and/or compounds present in said target cell population.

There is provided a method of guiding ions, comprising providing an ion guide comprising a plurality of electrodes, confining ions radially within said ion guide by applying one or more voltages to said plurality of electrodes, applying an orthogonal DC field along at least a portion of said ion guide in order to control the temperature of ions as they travel through said ion guide, and applying an electrostatic driving potential to said plurality of electrodes to urge ions along the axial length of the ion guide, wherein said electrostatic driving potential is applied in the form of a DC travelling wave potential or other transient DC potential.

An electrode assembly, such as for an ion mirror, comprising: a first layer having a plurality of electrodes that are separated by one or more gaps; a second layer arranged to cover said one or more gaps and prevent electric fields passing through said one or more gaps, said second layer having electrically conductive material located to be coincident with said one or more gaps in the first layer.

A method of analysis using mass spectrometry and/or ion mobility spectrometry is disclosed. The method comprises: using a first device to generate smoke, aerosol or vapour from a target comprising or consisting of a microbial population; mass analysing and/or ion mobility analysing said smoke, aerosol or vapour, or ions derived therefrom, in order to obtain spectrometric data; and analysing said spectrometric data in order to analyse said microbial population.

A method of analysis using mass and/or ion mobility spectrometry or ion mobility spectrometry is disclosed comprising: using a first device to generate aerosol, smoke or vapour from one or more regions of a first target of biological material; and mass and/or ion mobility analysing and/or ion mobility analysing said aerosol, smoke, or vapour, or ions derived therefrom so as to obtain first spectrometric data. The method may use an ambient ionisation method.

A method of analysis using mass spectrometry and/or ion mobility spectrometry is disclosed. The method comprises: using a first device to generate smoke, aerosol or vapour from a target comprising or consisting of a microbial population; mass analysing and/or ion mobility analysing said smoke, aerosol or vapour, or ions derived therefrom, in order to obtain spectrometric data; and analysing said spectrometric data in order to analyse said microbial population.

A method of mass spectrometry or ion mobility spectrometry is disclosed comprising: providing an analyte; supplying a matrix compound to said analyte such that said analyte dissolves in said matrix; forming first droplets of the dissolved analyte; and colliding said first droplets with a collision surface. The use of matrix improves the analyte ion signal.