摘要:
An Electrospray Ionisation ion source and an Atmospheric Pressure Chemical Ionisation ion source are disclosed which comprise a probe 1 comprising three co-axial capillary tubes 2,3,3′. A blue-flame gas torch 6 is provided downstream of the probe 1 as a combustion source. An analyte solution is sprayed from an inner capillary tube 2 of the probe 1, a combustible gas is supplied to an intermediate capillary tube 3 of the probe 1 and oxygen or air is supplied to an outer capillary tube 3′ of the probe 1. The combustible gas supplies heat to aid desolvation of the droplets emerging from the probe 1 via combustion with the surrounding oxygen-containing atmosphere when combusted by the blue flame torch 6.
摘要:
A mass spectrometer is disclosed wherein the experimentally determined mass to charge ratios of ions are reported together with an error band for each mass to charge ratio determination. The error band may, for example, reflect a 95% probability or confidence that the real, true, actual or accepted mass to charge ratio of the ion lies within the error band. By accurately determining the error band the possible candidate ions in a database can be accurately restricted whilst also guarding against over restriction.
摘要:
An ion detector for a mass spectrometer is disclosed comprising one or more microchannel plates and an anode arranged to receive electrons emitted from the one or more microchannel plates. The anode preferably has a smaller diameter than the microchannel plates and is preferably arranged at a distance of at least 15 mm from the microchannel plates. One or more focusing lenses may be provided intermediate the microchannel plates and the anode. The anode preferably comprises two portions separated by an electrically insulated layer.
摘要:
A mass spectrometer is disclosed comprising an ion guide which spans two or more vacuum chambers. The ion guide comprises a plurality of electrodes having apertures. Preferably, one of the electrodes also forms a differential pumping aperture which separates two vacuum chambers.
摘要:
A Time of Flight mass analyser is disclosed comprising an ion detector comprising an Analogue to Digital Converter. Output signals from the ion detector are digitised and the arrival times and intensity values relating to ion arrival events are determined. If the determined arrival times from two signals fall within the same time window then the arrival times are added together in a weighted manner and the intensity values are combined.
摘要:
A collision or fragmentation cell is disclosed comprising a plurality of electrodes wherein a first RF voltage is applied to an upstream group of electrodes and a second different RF voltage is applied to a downstream group of electrodes. The radial confinement of parent ions entering the collision or fragmentation cell is optimized by the first RF voltage applied to the upstream group of electrodes and the radial confinement of daughter or fragment ions produced within the collision or fragmentation cell is optimized by the second different RF voltage applied to the downstream group of electrodes.
摘要:
A mass spectrometer is disclosed comprising an ion mobility spectrometer or separator and an ion guide arranged downstream of the ion mobility spectrometer or separator. A plurality of axial potential wells are created in the ion guide so that ions received from the ion mobility spectrometer or separator become confined in separate axial potential wells. The potential wells maintain the fidelity and/or composition of ions received from the ion mobility spectrometer or separator. The potential wells are translated along the length of the ion guide.
摘要:
A method of mass spectrometry is disclosed wherein voltage signals from an ion detector are analyzed. A second differential of each voltage signal is obtained and the start and end times of observed voltage peaks are determined. The intensity and average time of each voltage peak is then determined and the intensity and time values are stored. An intermediate composite mass spectrum is then formed by combining the intensity and time values which relate to each voltage peak observed from multiple experimental runs. The various pairs of time and intensity data are then integrated to produce a smooth continuum mass spectrum. The continuum mass spectrum may then be further processed by determining the second differential of the continuum mass spectrum. The start and end times of mass peaks observed in the continuum mass spectrum may be determined. The intensity and mass to charge ratio of each mass peak observed in the continuum mass spectrum may then determined. A final discrete mass spectrum comprising just of an intensity value and mass to charge ratio per species of ion may then be displayed or output.
摘要:
A collision or fragmentation cell (4) is disclosed comprising a plurality of electrodes wherein a first RF voltage (7a) is applied to an upstream group of electrodes and a second different RF voltage (7b) is applied to a downstream group of electrodes. The radial confinement of parent ions entering the collision or fragmentation cell (4) is optimised by the first RF voltage applied to the upstream group of electrodes and the radial confinement of daughter or fragment ions produced within the collision or fragmentation cell (4) is optimised by the second different RF voltage applied to the downstream group of electrodes.
摘要:
A mass spectrometer is disclosed comprising a High Pressure Liquid Chromatography system (10) which is interfaced to a combustion chamber (16) and isotope ratio mass analyser (19) by means of an Electrospray Ionisation ion source (11) and a Field Asymmetric Ion Mobility Spectrometry device (13). Analyte and solvent molecules are ionised by the ion source (11). Desired analyte ions are substantially onwardly transmitted by the Field Asymmetric Ion Mobility Spectrometry device (13) to the combustion chamber (16) whereas undesired solvent ions are substantially attenuated by the Field Asymmetric Ion Mobility Spectrometry device (13).