A mass spectrometry apparatus includes an ion detector and a control circuit coupled to the ion detector. The ion detector includes a pulse counting stage and an analog stage configured to generate a pulse counting signal and an analog signal, respectively, responsive to incident ions. The a control circuit is configured to output the pulse counting signal in a pulse counting output mode and to output the analog signal in an analog output mode. The control circuit is configured to switch from the pulse counting output mode to the analog output mode responsive to the pulse counting signal exceeding a first threshold within a range of about 10 million counts per second to about 200 million counts per second. Related devices and operating methods are also discussed.

A dual polarity ion detector comprises: an entrance electrode disposed to receive ions and maintained at a reference voltage, V.sub.0; a first dynode maintained at a voltage, V.sub.1, that is negative relative to V.sub.0; a second dynode maintained at a voltage, V.sub.2, that is positive relative to V.sub.0; a shielding electrode disposed between the first and second dynodes and maintained at a voltage, V.sub.3; and an ion detector comprising an entrance aperture configured to receive first secondary particles from the first dynode and second secondary particles from the second dynode, the entrance aperture maintained at a voltage, V.sub.aperture; that is intermediate between the voltage, V.sub.1, and the voltage, V.sub.2. In some instances, the voltage, V.sub.3, may be equal to or approximately equal to the voltage, V.sub.0.

A gas chromatograph mass spectrometer includes a separator that separates a sample, and a mass analyzer that performs mass spectrometry on the sample introduced from the separator, the mass analyzer includes a filament and an ionization chamber into which thermal electrons from the filament and the sample from the separator are introduced, and an opening through which the thermal electrons emitted from the filament pass and which is formed in the ionization chamber or in a member arranged between the ionization chamber and the filament has a maximum diameter of less than 3 mm.

A method that includes accelerating ions toward a lattice of carbon fibers and capturing the ions in the lattice of carbon fibers.

An instrument for separating ions may include an ion source configured to generate ions from a sample, at least one ion separation instrument configured to separate the generated ions as a function of at least one molecular characteristic and an electrostatic linear ion trap (ELIT) positioned to receive ions exiting the at least one ion separation instrument. The ELIT has first and second ion mirrors separated by a charge detection cylinder, and is configured such that an ion trapped therein oscillates back and forth through the charge detection cylinder between the first and second ion mirrors with a duty cycle, corresponding to a ratio of time spent by the trapped ion traversing the charge detection cylinder and total time spent by the trapped ion traversing a combination of the first and second ion mirrors and the charge detection cylinder during one complete oscillation cycle, of approximately 50%.

An ion detector that can detect either positive or negative ions comprises: an ion inlet comprising an ion focusing lens; a dynode having a surface configured to intercept, within a zone of interception, a stream of ions passing through the ion focusing lens, wherein a plane that is tangent to the dynode surface at the zone of interception is disposed at an angle to a line that passes through the center of the dynode surface and the center of the focusing lens; a scintillator having a surface that is configured to receive secondary electrons emitted from the zone of interception; a scintillator electrode affixed to the scintillator surface; a photodetector configured to receive photons emitted by the scintillator and to generate an electric signal in response thereto; and one or more power supplies electrically coupled to the focusing lens, the dynode, the scintillator electrode and the photodetector.

A device of detecting a current from a sensor is disclosed. The device includes an integrating circuit including a network of capacitors for providing a gain setting and configured to convert the current to a voltage ramp over a length of integration time, the integrating circuit further including a reset switch configured to connect an input and an output of the network of capacitors; an ADC configured to digitize the voltage ramp into a plurality of voltage samples; and a set of modules including an analyzing module configured to analyze the plurality of voltage samples to determine a slope of the voltage ramp; an outputting module configured to determine a magnitude of the current based on the slope of the voltage ramp and the gain setting; and a reconfiguring module that is configured to reconfigure the network of capacitors and reset the voltage ramp via the reset switch.

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.

In a sampling interface for mass spectrometry, a method and apparatus are set forth for preventing liquid overflow from a sampling probe into a sample. The apparatus comprises a substrate adapted to retain a droplet of liquid as it forms at an open end of the sampling probe, and a sensor on a surface of the substrate opposite the sample adapted to detect the droplet of liquid and generate a signal for controlling the droplet of liquid before it overflows into the sample.

Certain embodiments described herein are directed to detectors and systems using them. In some examples, the detector can include a plurality of dynodes, in which one or more of the dynodes are coupled to an electrometer. In some instances, an analog signal from a non-saturated dynode is measured and cross-calibrated with a pulse count signal to extend the dynamic range of the detector.