A method for cleaning a first electrospray emitter of a mass spectrometer comprises: changing an operating mode of the first electrospray emitter from a stable jet mode of operation to a dripping or pulsating mode of operation by lowering a magnitude of a voltage applied between a counter electrode and the first electrospray emitter, |V.sub.1|; moving the first electrospray emitter from a first emitter position from which electrospray ions are delivered to a mass spectrometer inlet to a second emitter position and, simultaneously, moving a second electrospray emitter from a third emitter position to a fourth emitter position; causing a cleaning solvent to flow through the first electrospray emitter at least until a droplet of the cleaning solvent forms on an exterior surface of the first electrospray emitter while operating the electrospray emitter in the dripping mode of operation; and causing the droplet to dislodge from the emitter exterior.

Scientific instruments (such as mass spectrometers) include an electron multiplier and a cross-filed ion detector including an ion impact plate. The electron multiplier receives and amplifies secondary electrons emitted by the impact plate to generate an output signal. The output signal is amplified and subsequently digitized. Amplification is limited so as to keep secondary electrons to a maximum thereby decreasing electron flux and improving instrument life.

A mass spectrometer may have an ion source region including an ion generator configured to generate ions from a sample, an ion detector configured to detect ions and produce corresponding ion detection signals, an electric field-free drift region disposed between the ion source region and the ion detector through which the generated ions drift axially toward the ion detector, a plurality of spaced-apart charge detection cylinders disposed in the drift region and through which the ions drifting axially through the drift region pass, and a plurality of charge amplifiers each coupled to a different one of the plurality of charge detection cylinders and each configured to produce a charge detection signal corresponding to a magnitude of charge of one or more of the generated ions passing through a respective one of the plurality of charge detection cylinders.

A mass spectrometer system (10) is provided in which the voltage controller (12) can have separate first and second high-voltage control circuits (34, 40) which are physically disconnected from and at different ground planes to one another. Communication between the first and second high-voltage control circuits (34, 40) is enabled via an interface circuit (30) and one or more wireless, preferably radio-frequency, communicators (38, 44, 46, 48).

The present disclosure is directed to an ion funnel and associated systems, where the ion funnel includes a plurality of electrodes each define an opening having an associated inner dimension and receive a RF voltage. The associated inner dimensions progressively reduce in size from approximately a first inner dimension to approximately a second inner dimension. The electrodes define an internal chamber having an outer dimension that reduces at a convergence angle of approximately 30 degrees for at least a majority of a length of the internal chamber from the first inner dimension to the second inner dimension. Additional systems and methods are provided for transferring ions from an ion funnel to an ion mobility device having a pressure greater than that of the ion funnel, for selectively transferring ions from the ion funnel to the ion mobility device, and for stripping ions of certain molecules adducted thereto during transfer.

Scientific analytical equipment including apparatus and methods for detecting and quantitating particles, and particularly ions generated in the course of mass spectroscopy. In one version, a particle detection apparatus includes electron emissive surfaces which emit secondary electrons in response to impact with a particle, the apparatus maintaining spatial separation between: (i) secondary electrons emitted as a result of the impact of a first particle in a first region of the electron emissive surface; and (ii) secondary electrons emitted as a result of the impact of a second particle in a second region of the electron emissive surface.

A method for characterizing or quantifying one or more proteins in visible and/or sub-visible particles formed in a sample by detecting the at least one visible or sub-visible particle in the sample, isolating and capturing the at least one visible or sub-visible particle to identify a presence of a protein, and using a mass spectrometer to characterize the protein.

A method for characterizing or quantifying one or more proteins in visible and/or sub-visible particles formed in a sample by detecting the at least one visible or sub-visible particle in the sample, isolating and capturing the at least one visible or sub-visible particle to identify a presence of a protein, and using a mass spectrometer to characterize the protein.

A pulse shaping circuit for a spectrometer comprises a circuit input terminal for receiving detector pulses from an analog ion detector, a flip-flop for receiving detector pulses from the circuit input terminal, a delay unit for receiving output pulses from the flip-flop and feeding delayed output pulses to a reset input terminal of said flip-flop, and a circuit output terminal for supplying the output pulses or the delayed output pulses to a counter. The duration of the output pulses and the minimum duration of the interval between the output pulses is determined by the delay unit. The pulse shaping circuit may comprise at least one Schmitt trigger.

A secondary ion mass spectrometer comprising a primary ion beam device, and means for collecting, mass filtering and subsequently detecting secondary ions released from a sample due to the sample having been impacted by a plurality of primary ion beams. The secondary ion mass spectrometer is remarkable in that it uses a plurality of primary ion beams in parallel for scanning the surface of the sample.