Abstract: A method of mass spectrometry or ion mobility spectrometry is disclosed in which analyte ions of a desired charge state are isolated. The method comprises: separating analytes according to their electrophoretic mobility; ionising the analytes; and mass filtering the resulting analyte ions, wherein the mass to charge ratios of the ions transmitted by a mass filter are varied as a function of the electrophoretic mobility and according to a predetermined relationship such that substantially only ions having said desired charge state are transmitted by the mass filter.

Abstract: A method of mass spectrometry is disclosed comprising digitizing a plurality of individual signals or transients and summing the plurality of digitized signals or transients or data relating to the plurality of digitized signals or transients to generate a composite mass spectral data set. The method further comprises determining in relation to the composite mass spectral data set an indication of the proportion of instances that intensity values relating to the individual digitized signals or transients either: (i) exceeded or approached a threshold value; (ii) suffered from saturation or approached saturation; or (iii) resulted from the dynamic range of an ion detector system being exceeded or approached.

Abstract: A method of mass spectrometry is disclosed comprising digitizing a signal output from a detector to provide a first digitized signal. A finite impulse response (“FIR”) filter, a digital filter or an echo cancellation filter is applied to the first digitized signal in order to reduce the effect of baseline perturbations, echoes or ringing effects. Alternatively, an analog signal output from a detector is passed to one or more first power splitters or dividers, wherein one or more first transmission lines are attached to one or more ports of one more said first power splitters or dividers in order to reduce the effect of baseline perturbations, echoes or ringing effects.

Abstract: An apparatus is provided to separate ions temporally according to a physico-chemical property comprising an ion guide comprising a plurality of electrodes and a first device arranged and adapted to remove undesired ions remaining within the ion guide after ions of interest have exited the ion guide.

Abstract: A method of ion mobility spectrometry is disclosed comprising: transmitting a plurality of ions to an ion mobility separator 6; modulating the introduction of the ions into the ion mobility separator 6 at a first modulation frequency; separating the ions that enter the ion mobility separator 6 according to ion mobility; detecting ions that have exited the ion mobility separator with a detector of a time of flight mass analyser 8; varying the first modulation frequency with time; recording the intensity of the ion signal output from the detector to produce recorded data; modulating the recorded data as a function of the time that the data was recorded and at a second modulation frequency, wherein the second modulation frequency is varied as a function of the time that the data was recorded; and determining, from the variation in intensity of the ion signal in the modulated data as a function of the second modulation frequency, the ion mobilities of the ions that have been detected.

Abstract: A method of mass spectrometry or ion mobility spectrometry is disclosed. The method comprises: providing a plurality of species of ions; analyzing the ions during a plurality of sequential acquisition periods so as to obtain spectral data relating to the ions; varying the value of an operational parameter of the spectrometer such that it has different values during the different acquisition periods, wherein the spectral data obtained for a given ion varies depending on the value of the operational parameter; storing the spectral data obtained during the different acquisition periods separately; selecting a target ion; and then interrogating the spectral data so as to identify a set of first acquisition periods that include data corresponding to said target ion. Selecting spectral data from only a subset of the first acquisition periods allows the selection of the optimal spectral data for the target ion, while discarding less optimal data.

Abstract: A method of mass or ion mobility spectrometry is disclosed. The method comprises providing a spectrometer comprising an orifice between an atmospheric and a sub-atmospheric pressure region of the spectrometer, wherein the latter comprises an ion guide or ion trap; providing a sample probe comprising a needle assembly on which a sample is deposited or that is supplied with a sample; inserting the needle assembly through the orifice into the sub-atmospheric pressure region so that the sample is arranged within or adjacent to the ion guide or trap in the sub-atmospheric pressure region; and then desorbing the sample from the needle assembly within the sub-atmospheric pressure region and/or ionizing the sample within the sub-atmospheric pressure region so as to generate ions that enter the ion guide or ion trap. The proximity of the sample to the ion guide or trap allows analyte ions from the sample to be captured efficiently.

Abstract: A method of mass spectrometry or ion mobility spectrometry is disclosed in which analyte ions of a desired charge state are isolated. The method comprises: separating analytes according to their electrophoretic mobility; ionizing the analytes; and mass filtering the resulting analyte ions, wherein the mass to charge ratios of the ions transmitted by a mass filter are varied as a function of the electrophoretic mobility and according to a predetermined relationship such that substantially only ions having said desired charge state are transmitted by the mass filter.

Abstract: A mass spectrometer is disclosed comprising an ion mobility separation device for separating ions according to their ion mobility, a first quadrupole mass filter downstream of the ion mobility separation device, a control system arranged and adapted to scan and/or step the set mass of the first quadrupole mass filter a plurality of times over a first mass to charge ratio range of <±2 amu during the elution time of an ion mobility peak from the ion mobility separation device, and an analyser or ion detector downstream of the first quadrupole mass filter arranged and adapted to analyse or detect ions so as to acquire multi-dimensional ion mobility-mass to charge ratio data.

Abstract: A method of mass spectrometry is disclosed that comprises predicting 1 one or more first reaction products which may result from subjecting an analyte to one or more reactions of interest, calculating 2 one or more first masses or mass to charge ratios and one or more first ion mobility values, collision cross sections or interaction cross sections of at least some first reaction product ions which may be generated from the one or more first reaction products under first conditions, and calculating one or more second masses or mass to charge ratios and one or more second ion mobility values, collision cross sections or interaction cross sections of at least some second reaction product ions which may be generated from the one or more first reaction products under second different conditions.

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 method of mass spectrometry is disclosed comprising digitising a first signal output from an ion detector to produce a first digitised signal, detecting one or more peaks in the first digitised signal and determining a first area S0 or a first intensity I0 of the one or more peaks and a first arrival time T0 of the one or more peaks thereby forming a first list of data pairs and determining whether or not the first area S0 or the first intensity I0 exceeds a first threshold area Smax or a first threshold intensity Imax. The first threshold area Smax and the first threshold intensity Imax correspond respectively to a peak area and a peak intensity indicative of substantially simultaneous arrival of two ions which the ion detector is unable to resolve.

Abstract: A method of mass and/or ion mobility spectrometry is disclosed that comprises accumulating ions for a first period of time (T1) one or more times so as to form one or more first groups of ions, accumulating ions for a second period of time (T2) one or more times so as to form one or more second groups of ions, wherein the second period of time (T2) is less that the first period of time (T1), analysing the one or more first groups of ions to generate one or more first data sets, analysing the one or more second groups of ions to generate one or more second data sets, and determining whether the one or more first data sets comprise saturated and/or distorted data. If it is determined that the one or more first data sets comprise saturated and/or distorted data, then the method further comprises replacing the saturated and/or distorted data from the one or more first data sets with corresponding data from the one or more second data sets.

Abstract: A method of fragmenting ions is disclosed comprising providing a linear ion trap comprising: (i) a first electrode set comprising a plurality of first electrodes; (ii) a second electrode set arranged downstream of the first electrode set and comprising a plurality of second electrodes; and (iii) a third electrode set arranged downstream of the second electrode set and comprising a plurality of third electrodes. Ions are axially confined within the linear ion trap. Either: (i) a potential difference between at least some of the first electrodes and at least some of the second electrodes; and/or (ii) a potential difference between at least some of the second electrodes and at least some of the third electrodes, is varied in order to accelerate at least some ions confined within the linear ion trap in order to cause the ions to fragment so as to form fragment or daughter ions.

Abstract: A method of mass spectrometry is disclosed wherein ions are subjected to an electron detachment, electron capture or electron transfer process in order to form ions having a different charge state. At least some of the ions having a different charge state are caused to interact with analyte ions to cause at least some of the analyte ions to fragment to form daughter, fragment or product ions.

Abstract: A method of analyzing ions by ion mobility separation is disclosed. The method comprises controlling the amount of charge within an ion trap and then pulsing the ions from the ion trap into an ion mobility separator. This enables the charge injected into the ion mobility separator to be controlled and hence prevents space-charge interactions between the ions from distorting the ion mobility peaks detected by the detector.

Abstract: A mass spectrometer is disclosed comprising an ion mobility separation device for separating ions according to their ion mobility, a first quadrupole mass filter downstream of the ion mobility separation device, a control system arranged and adapted to scan and/or step the set mass of the first quadrupole mass filter a plurality of times over a first mass to charge ratio range of <±2 amu during the elution time of an ion mobility peak from the ion mobility separation device, and an analyzer or ion detector downstream of the first quadrupole mass filter arranged and adapted to analyze or detect ions so as to acquire multi-dimensional ion mobility-mass to charge ratio data.

Abstract: A method of constructing an ion guide is disclosed comprising providing an elongated spine member and a plurality of plates. Each plate comprises an aperture therethrough for receiving the spine member and at least one electrode for use in guiding ions. The apertures of the plates are arranged around the spine member and the plates are arranged along the spine member. The plates are then locked in position on the spine member such that the plates are fixed axially with respect to the spine member and so that the electrodes of the plates are arranged so as to form an array of electrodes for use in guiding ions.

Abstract: A method of analyzing ions, comprising performing an initial multidimensional survey scan comprising separating parent ions according to a first physico-chemical property and separating said parent ions according to a second physico-chemical property, producing a two-dimensional data set comprising data corresponding to said first physico-chemical property and data corresponding to said second physico-chemical property, identifying one or more target ion species of interest and determining a mode of operation of a mass spectrometer for said target ion species of interest using data relating to said target ion species of interest in said two-dimensional data set, wherein said mode of operation comprises the location of fragmentation of said target ions of interest.

Abstract: A method of mass spectrometry for analyzing lipids and similar biological molecules is disclosed. The lipid molecules may be ionized to form a plurality of lipid parent ions and subjected to photon-induced fragmentation to form a plurality of fragment or product ions. The position of one or more unsaturated bonds in the lipid molecules may be determined by mass analyzing the fragment and product ions and analyzing their intensity profile.