Abstract: A mass spectrometer or ion mobility spectrometer is disclosed comprising means for detecting a blockage in an inlet orifice arranged between an ion source and a vacuum chamber. The blockage is detected as a result of a reduction in pressure within the vacuum chamber. This change in pressure is detected indirectly by monitoring the amount of power that a vacuum pump is using, the amount of current that a vacuum pump is drawing, the temperature of a vacuum pump or a region in proximity to the vacuum pump, or the flow rate of gas out of a vacuum pump.

Abstract: A method of Electrospray ionisation is disclosed comprising passing a sample liquid through a liquid chromatography column, monitoring a liquid chromatography back pressure and varying a voltage applied to an Electrospray ionisation source electrode in dependence upon said monitored liquid chromatography back pressure.

Abstract: A mass spectrometer is disclosed comprising an atmospheric pressure interface comprising a gas cone having an inlet aperture, wherein the gas cone has a first longitudinal axis arranged along an x-axis and an Electrospray ion source comprising a first capillary tube having an outlet and having a second longitudinal axis and a second capillary tube which surrounds the first capillary tube. The mass spectrometer further comprises a desolvation gas supply tube and a first device arranged and adapted to supply an analyte liquid via the first capillary tube so that the liquid exits the outlet of the first capillary tube at a flow rate >200 ?L/min.

Abstract: An ion guide or mass analyser is disclosed comprising a plurality of electrodes having apertures through which ions are transmitted in use. A pseudo-potential barrier is created at the exit of the ion guide or mass analyser. The amplitude or depth of the pseudo-potential barrier is inversely proportional to the mass to charge ratio of an ion. One or more transient DC voltages are applied to the electrodes of the ion guide or mass analyser in order to urge ions along the length of the ion guides or mass analyser. The amplitude of the transient DC voltage applied to the electrode may be increased with time so that ions are caused to be emitted from the ion guide or mass analyser in reverse order of their mass to charge ratio.

Abstract: 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.

Abstract: A method of mass spectrometry is disclosed comprising automatically correcting the mass or mass to charge ratio resolution of a quadrupole mass filter or mass analyser one or more times during an experimental run or acquisition based upon a measurement, determination or estimation of the mass or mass to charge ratio resolution of one or more reference ions observed in a mass spectrum or mass spectral data acquired either during the same experimental run or acquisition or during a previous experimental run or acquisition.

Abstract: 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. 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 product of the pressure P1 in the vicinity of the first RF ion guide and the length L1 of the first RF ion guide is in the range 10-100 mbar-cm and the product of the pressure P2 in the vicinity of the second RF ion guide and the length L2 of the second RF ion guide is in the range 0.05-0.3 mbar-cm.

Abstract: An ion source for a mass spectrometer is disclosed comprising a lens and mirror arrangement which focuses a laser beam onto the upper surface of a target substrate. The lens has an effective focal length ?300 mm. The laser beam is directed onto the target substrate at an angle ? with respect to the perpendicular to the target substrate, wherein ??3°. One or more ion guides receive ions released from the target substrate and onwardly transmit the ions along an ion path which substantially bypasses the lens and mirror.

Abstract: 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. 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. The mass spectrometer further comprises a split flow turbomolecular vacuum pump comprising an intermediate or interstage port connected to the second vacuum chamber and a high vacuum (“HV”) port connected to the third vacuum chamber.

Abstract: A miniature mass spectrometer is disclosed comprising an atmospheric pressure ionisation 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 analyser, a 3D ion trap mass analyser, a 2D or linear ion trap mass analyser, a Time of Flight mass analyser, a quadrupole-Time of Flight mass analyser or an electrostatic mass analyser arranged in the third vacuum chamber.

Abstract: A method of mass spectrometry is disclosed comprising automatically and repeatedly performing multiple cycles of operation, wherein a cycle of operation comprises the steps of: (i) mass analyzing first ions; (ii) exposing the first ions to a first photo-dissociation device to form a plurality of second ions and mass analyzing the second ions; and (iii) exposing the first ions to a first photo-dissociation device to form a plurality of second ions, fragmenting the second ions to form a plurality of third ions and mass analyzing the third ions.

Abstract: An ion source for a mass spectrometer is disclosed comprising a lens and mirror arrangement which focuses a laser beam onto the upper surface of a target substrate. The lens has an effective focal length?300 mm. The laser beam is directed onto the target substrate at an angle ? with respect to the perpendicular to the target substrate, wherein ??3°. One or more ion guides receive ions released from the target substrate and onwardly transmit the ions along an ion path which substantially bypasses the lens and mirror.

Abstract: An ion guide or mass analyzer is disclosed comprising a plurality of electrodes having apertures through which ions are transmitted in use. A pseudo-potential barrier is created at the exit of the ion guide or mass analyzer. The amplitude or depth of the pseudo-potential barrier is inversely proportional to the mass to charge ratio of an ion. One or more transient DC voltages are applied to the electrodes of the ion guide or mass analyzer in order to urge ions along the length of the ion guides or mass analyzer. The amplitude of the transient DC voltage applied to the electrode may be increased with time so that ions are caused to be emitted from the ion guide or mass analyzer in reverse order of their mass to charge ratio.

Abstract: A mass spectrometer is disclosed comprising two vacuum chambers maintained at different pressures. The two vacuum chambers are interconnected by a differential pumping aperture. The effective area of the opening between the two vacuum chambers may be varied by rotating a disk having an aperture in front of the differential pumping aperture so as to vary the gas flow rate through the opening and between the two chambers.

Abstract: A non-linear ion guide is disclosed comprising a plurality of electrodes. An ion guiding region is arranged between the electrodes, and the ion guiding region curves at least in a first direction. A DC voltage is applied to at least some of the electrodes in order to form a DC potential well which acts to confine ions within the ion guiding region in the first direction.

Abstract: An ion source for a mass spectrometer is disclosed comprising a lens and mirror arrangement which focuses a laser beam onto the upper surface of a target substrate. The lens has an effective focal length ?300 mm. The laser beam is directed onto the target substrate at an angle ? with respect to the perpendicular to the target substrate, wherein ??3°. One or more ion guides receive ions released from the target substrate and onwardly transmit the ions along an ion path which substantially bypasses the lens and mirror.

Abstract: An ion guide is disclosed wherein an axial DC voltage barrier is created at the exit of the ion guide. A primary RF voltage is applied to the electrodes in order to confine ions radially within the ion guide. A supplemental RF voltage is also applied to the electrodes. The supplemental RF voltage has a greater axial repeat length than that of the primary RF voltage. The amplitude of the supplemental RF voltage is increased with time causing ions to become unstable and gain sufficient axial kinetic energy such that the ions overcome the axial DC voltage barrier. Ions emerge axially from the ion guide in mass to charge ratio order.

Abstract: A mass or mass to charge ratio selective ion trap is disclosed which directs ions into a small ejection region. A RF voltage acts to confine ions in a first (y) direction within the ion trap. A DC or RF voltage acts to confine ions in a second (x) direction. A quadratic DC potential well acts to confine ions in a third (z) direction within the ion trap. The profile of the quadratic DC potential well progressively varies along the second (x) direction.

Abstract: A mass spectrometer is disclosed comprising two vacuum chambers maintained at different pressures. The two vacuum chambers are interconnected by a differential pumping aperture. The effective area of the opening between the two vacuum chambers may be varied by rotating a disk having an aperture in front of the differential pumping aperture so as to vary the gas flow rate through the opening and between the two chambers.

Abstract: Ions having a restricted range of mass to charge ratios are transmitted to the acceleration region of a Time of Flight mass analyser. A control system applies a first extraction pulse to an acceleration electrode in order to accelerate a first group of ions into the time of flight region at a first time T1, wherein ions having the lowest mass to charge ratio in the first group of ions have a time of flight ?T1min through the time of flight region and ions having the highest mass to charge ratio in the first group of ions have a time of flight ?T1max through the time of flight region. The control system applies a second extraction pulse to the acceleration electrode at a subsequent second time T2, wherein ?T1max??T1min?T2?T1<?T1max.