EP1505635B1 - Mass spectrometers and methods of mass spectrometry - Google Patents
Mass spectrometers and methods of mass spectrometry Download PDFInfo
- Publication number
- EP1505635B1 EP1505635B1 EP04026520A EP04026520A EP1505635B1 EP 1505635 B1 EP1505635 B1 EP 1505635B1 EP 04026520 A EP04026520 A EP 04026520A EP 04026520 A EP04026520 A EP 04026520A EP 1505635 B1 EP1505635 B1 EP 1505635B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- mbar
- vacuum chamber
- ion guide
- mass spectrometer
- ion
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J49/00—Particle spectrometers or separator tubes
- H01J49/02—Details
- H01J49/06—Electron- or ion-optical arrangements
- H01J49/062—Ion guides
- H01J49/065—Ion guides having stacked electrodes, e.g. ring stack, plate stack
Definitions
- the present invention relates to mass spectrometers and methods of mass spectrometry.
- Ion guides comprising rf-only multipole rod sets such as quadrupoles, hexapoles and octopoles are well known.
- An alternative type of ion guide known as an "ion funnel” has recently been proposed by Smith and coworkers at Pacific Northwest National Laboratory.
- An ion funnel comprises a stack of ring electrodes of constant external diameter but which have progressively smaller internal apertures.
- a dc voltage/potential gradient is applied along the length of the ion guide in order to urge ions through the ion funnel which would otherwise act as an ion mirror.
- a variant of the standard ion funnel arrangement is disclosed in Anal. Chem. 2000, 72, 2247-2255 and J. Am. Soc. Mass Spectrom. 2000, 11, 19-23 (Belov) and comprises an initial drift section comprising ring electrodes having constant internal diameters and a funnel section comprising ring electrodes having uniformly decreasing internal diameters. A dc voltage gradient is applied across both sections in order to urge ions through the ion funnel.
- ion funnels suffer from a narrow bandpass transmission efficiency i.e. the ion funnel may, for example, only efficiently transmit ions having mass to charge ratios ("m/z") falling within a narrow range e.g. 100 ⁇ m/z ⁇ 200.
- m/z mass to charge ratios
- pages 2249 and 2250 of Anal. Chem 2000, 72, 2247-2255 which similarly recognises that ion funnels suffer from an undesirably narrow m/z transmission window.
- ion funnel ion guides require both an rf voltage and a dc voltage gradient to be applied to the ring electrodes.
- the design and manufacture of a reliable power supply capable of supplying both an rf voltage and a dc voltage gradient which is decoupled from the rf voltage is a non-trivial matter and increases the overall manufacturing cost of the mass spectrometer.
- US-5818055 discloses a method and device for injection of ions into an ion trap.
- the preferred embodiment comprises a plurality of electrodes wherein most if not all of the electrodes have apertures which are substantially the same size.
- the apertures are preferably circular in shape, and the outer circumference of the electrodes may also be circular.
- the electrodes may comprise ring or annular electrodes.
- the outer circumference of the electrodes does not need to be circular and embodiments of the present invention are contemplated wherein the outer profile of the electrodes may take on other shapes.
- the preferred embodiment wherein the internal apertures of each of the electrodes are either identical or substantially similar is referred to hereinafter as an "ion tunnel" in contrast to ion funnels which have ring electrodes with internal apertures which become progressively smaller in size.
- One advantage of the preferred embodiment is that the ion guide does not suffer from a narrow or limited mass to charge ratio transmission efficiency which appears to be inherent with ion funnel arrangements.
- Another advantage of the preferred embodiment is that a dc voltage gradient is not and does not need to be applied to the ion guide.
- the resulting power supply for the ion guide can therefore be significantly simplified compared with that required for an ion funnel thereby saving costs and increasing reliability.
- An additional advantage of the preferred embodiment is that it has been found to exhibit an approximately 75% improvement in ion transmission efficiency compared with a conventional multipole, e.g. hexapole, ion guide. The reasons for this enhanced ion transmission efficiency are not fully understood, but it is thought that the ion tunnel may have a greater acceptance angle and a greater acceptance area than a comparable multipole rod set ion guide.
- the preferred ion guide therefore represents a significant improvement over other known ion guides.
- ion optical devices other than an ion tunnel ion guide
- multipole rod sets Einzel lenses, segmented multipoles, short (solid) quadrupole pre/post filter lenses ("stubbies"), 3D quadrupole ion traps comprising a central doughnut shaped electrode together with two concave end cap electrodes, and linear (2D) quadrupole ion traps comprising a multipole rod set with entrance and exit ring electrodes.
- stubbies 3D quadrupole ion traps comprising a central doughnut shaped electrode together with two concave end cap electrodes
- 2D linear quadrupole ion traps comprising a multipole rod set with entrance and exit ring electrodes
- the input vacuum chamber is arranged to be maintained at a relatively high pressure i.e. at least a few mbar.
- the input vacuum chamber may be arranged to be maintained at a pressure above a minimum value of 0.1 mbar and less than or equal to a maximum value such as 20 or 30 mbar.
- Embodiments of the present invention are also contemplated, wherein if the AC-only ion guide is considered to have a length L and is maintained in the input vacuum chamber at a pressure P, then the pressure-length product p x L is selected from the group comprising: (i) ⁇ 1 mbar cm; (ii) ⁇ 2 mbar cm; (iii) ⁇ 5 mbar cm; (iv) ⁇ 10 mbar cm; (v) ⁇ 15 mbar cm; (vi) ⁇ 20 mbar cm; (vii) ⁇ 25 mbar cm; (viii) ⁇ 30 mbar cm; (ix) ⁇ 40 mbar cm; (x) ⁇ 50 mbar cm; (xi) ⁇ 60 mbar cm; (xii) ⁇ 70 mbar cm; (xiii) ⁇ 80 mbar cm; (xiv) ⁇ 90 mbar cm; (xv) ⁇ 100 mbar cm; (xvi) ⁇ 110
- the electrodes are preferably relatively thin e.g. ⁇ 2 mm, further preferably ⁇ 1 mm, further preferably 0.5 ⁇ 0.2 mm, further preferably 0.7 ⁇ 0.1 mm thick. According to a particularly preferred embodiment the electrodes have a thickness within the range 0.5-0.7 mm in contrast to multipole rod sets which are typically > 10 cm long.
- Each, or at least a majority of the electrodes forming the AC-only ion guide may comprise either a plate having an aperture therein, or a wire or rod bent to form a closed ring or a nearly closed ring.
- the outer profile of the electrodes may or may not be circular.
- alternate electrodes are connected together and to one of the output connections of a single AC generator.
- the AC-only ion guide preferably comprises at least 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 60, 70, 80, 90 or 100 electrodes.
- the electrodes forming the AC-only ion guide may have internal diameters or dimensions selected from the group comprising: (i) ⁇ 5.0 mm; (ii) ⁇ 4.5 mm; (iii) ⁇ 4.0 mm; (iv) ⁇ 3.5 mm; (v) ⁇ 3.0 mm; (vi) ⁇ 2.5 mm; (vii) 3.0 ⁇ 0.5 mm; (viii) ⁇ 10.0 mm; (ix) ⁇ 9.0 mm; (x) ⁇ 8.0 mm; (x) ⁇ 7.0 mm; (xii) ⁇ 6.0 mm; (xiii) 5.0 t 0.5 mm; and (xiv) 4-6 mm.
- the length of the AC-only ion guide may be selected from the group comprising: (i) ⁇ 100 mm; (ii) ⁇ 120 mm; (iii) ⁇ 150 mm; (iv) 130 ⁇ 10 mm; (v) 100-150 mm; (vi) ⁇ 160 mm; (vii) ⁇ 180 mm; (viii) ⁇ 200 mm; (ix) 130-150 mm; (x) 120-180 mm; (xi) 120-140 mm; (xii) 130 mm ⁇ 5, 10, 15, 20, 25 or 30 mm; (xiii) 50-300 mm; (xiv) 150-300 mm; (xv) ⁇ 50 mm; (xvi) 50-100 mm; (xvii) 60-90 mm; (xviii) ⁇ 75 mm; (xix) 50-75 mm; and (xx) 75-100 mm.
- An intermediate vacuum chamber is disposed between the input vacuum chamber and the analyzer vacuum chamber, the intermediate vacuum chamber comprising an AC-only ion guide for transmitting ions through the intermediate vacuum chamber.
- the AC-only ion guide arranged in the intermediate vacuum chamber preferably comprises a plurality of electrodes having apertures, the apertures being aligned so that ions travel through them as they are transmitted by the ion guide.
- At least one further differential pumping apertured electrode is provided through which ions may pass.
- the further differential pumping apertured electrode is disposed between the vacuum chambers to allow the intermediate vacuum chamber to be maintained at a lower pressure than the input vacuum chamber, and the analyzer vacuum chamber to be maintained at a lower pressure than the intermediate vacuum chamber.
- An alternating current (AC) generator is connected to an intermediate chamber reference potential for providing AC potentials to the AC-only ion guide in the intermediate vacuum chamber.
- At least 90%, and preferably 100%, of the apertures of the electrodes forming the AC-only ion guide in the intermediate vacuum chamber are substantially the same size, and at least 90%, and preferably 100%, of the plurality of the electrodes forming the AC-only ion guide in the intermediate vacuum chamber are connected to the AC generator connected to the intermediate chamber reference potential in such a way that at any instant during an AC cycle of the output of the AC generator, adjacent ones of the electrodes forming the AC-only ion guide arranged in the intermediate vacuum chamber are supplied respectively with approximately equal positive and negative potentials relative to the intermediate chamber reference potential.
- the AC-only ion guide in the intermediate vacuum chamber comprises at least 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 60, 70, 80, 90, or 100 electrodes.
- the intermediate vacuum chamber is arranged to be maintained at a pressure selected from the group comprising: (i) 10 -3 -10 -2 mbar; (ii) ⁇ 2 x 10 -3 mbar; (iii) ⁇ 5 x 10 -3 mbar; (iv) ⁇ 10 -2 mbar; (v) 10 -3 -5 x 10 -3 mbar; and (vi) 5 x 10 -3 -10 -2 mbar.
- the electrodes forming the AC-only ion guide in the intermediate vacuum chamber have internal diameters or dimensions selected from the group comprising: (i) ⁇ 5.0 mm; (ii) ⁇ 4.5 mm; (iii) ⁇ 4.0 mm; (iv) ⁇ 3.5 mm; (v) ⁇ 3.0 mm; (vi) ⁇ 2.5 mm; (vii) 3.0 ⁇ 0.5 mm; (viii) ⁇ 10.0 mm; (ix) ⁇ 9.0 mm; (x) ⁇ 8.0 mm; (xi) ⁇ 7.0 mm; (xii) ⁇ 6.0 mm; (xiii) 5.0 ⁇ 0.5 mm; and (xiv) 4-6 mm.
- the individual electrodes in the AC-only ion guide in the input vacuum chamber and/or the AC-only ion guide in the intermediate vacuum chamber preferably have a substantially circular aperture having a diameter selected from the group comprising: (i) 0.5-1.5 mm; (ii) 1.5-2.5 mm; (iii) 2.5-3.5 mm; (iv) 3.5-4.5 mm; (v) 4.5-5.5 mm; (vi) 5.5-6.5 mm; (vii) 6.5-7.5 mm; (viii) 7.5-8.5 mm; (ix) 8.5-9.5 mm; (x) 9.5-10.5 mm; and (xi) ⁇ 10mm.
- the length of the ion guide in the intermediate vacuum chamber is selected from the group comprising: (i) ⁇ 100 mm; (ii) ⁇ 120 mm; (iii) ⁇ 150 mm; (iv) 130 ⁇ 10 mm; (v) 100-150 mm; (vi) ⁇ 160 mm; (vii) ⁇ 180 mm; (viii) ⁇ 200 mm; (ix) 130-150 mm; (x) 120-180 mm; (xi) 120-140 mm; (xii) 130 mm ⁇ 5, 10, 15, 20, 25 or 30 mm; (xiii) 50-300 mm; (xiv) 150-300 mm; (xv) ⁇ 50 mm; (xvi) 50-100 mm; (xvii) 60-90 mm; (xviii) ⁇ 75 mm; (xix) 50-75 mm; and (xx) 75-100 mm.
- the ion source is an atmospheric pressure ion source.
- the ion source is a continuous ion source.
- An Electrospray (“ES”) ion source or an Atmospheric Pressure Chemical Ionisation (“APCI”) ion source is particularly preferred.
- the ion source is either an Inductively Coupled Plasma (“ICP”) ion source or a Matrix Assisted Laser Desorption Ionisation (“MALDI”) ion source at low vacuum or at atmospheric pressure.
- ICP Inductively Coupled Plasma
- MALDI Matrix Assisted Laser Desorption Ionisation
- the ion mass analyser is selected from the group comprising: (i) a time-of-flight mass analyser, preferably an orthogonal time of flight mass analyser; (ii) a quadrupole mass analyser; and (iii) a quadrupole ion trap.
- the AC-only ion guide comprises two interleaved comb arrangements, each comb arrangement comprising a longitudinally extending bar or spine having a plurality of electrodes having apertures depending therefrom.
- the input vacuum chamber has a length and the combs arrangements extend at least x% of the length, x% selected from the group comprising: (i) ⁇ 50%; (ii) ⁇ 60%; (iii) ⁇ 70%; (iv) ⁇ 80%; (v) ⁇ 90%; and (vi) ⁇ 95%.
- a preferred ion tunnel 15 comprises a plurality of electrodes 15a,15b each having an aperture.
- the outer profile of the electrodes 15a,15b is circular.
- the outer profile of the electrodes 15a,15b does not need to be circular.
- the preferred embodiment may be considered to comprise a plurality of ring or annular electrodes, electrodes having other shapes are also contemplated as falling within the scope of the present invention.
- Adjacent electrodes 15a,15b are connected to opposite phases of an AC power supply.
- the first, third, fifth etc. ring electrodes 15a may be connected to the 0° phase supply 16a
- the second, fourth, sixth etc. ring electrodes 15b may be connected to the 180° phase supply 16b.
- the AC power supply may be a RF power supply.
- the present invention is not intended to be limited to RF frequencies.
- "AC" is intended to mean simply that the waveform alternates and hence embodiments of the present invention are also contemplated wherein non-sinusoidal waveforms including square waves are provided. Ions from an ion source pass through the ion tunnel 15 and are efficiently transmitted by it.
- the dc reference potential about which the AC signal oscillates is substantially the same for each electrode.
- blocking dc potentials are not applied to either the entrance or exit of the ion tunnel 15.
- Fig. 2 shows a conventional mass spectrometer.
- An Electrospray (“ES”) ion source 1 or an Atmospheric Pressure Chemical lonisation (“APCI”) 1,2 ion source emits ions which enter a vacuum chamber 17 pumped by a rotary or mechanical pump 4 via a sample cone 3 and a portion of the gas and ions passes through a differential pumping aperture 21 preferably maintained at 50-120V into a vacuum chamber 18 housing an rf-only hexapole ion guide 6. Vacuum chamber 18 is pumped by a rotary or mechanical pump 7.
- Ions are transmitted by the rf-only hexapole ion guide 6 through the vacuum chamber 18 and pass through a differential pumping aperture 8 into a further vacuum chamber 19 pumped by a turbo-molecular pump 10.
- This vacuum chamber 19 houses another rf-only hexapole ion guide 9.
- Ions are transmitted by rf-only hexapole ion guide 9 through vacuum chamber 19 and pass through differential pumping aperture 11 into a yet further vacuum chamber 20 which is pumped by a turbo-molecular pump 14.
- Vacuum chamber 20 houses a prefilter rod set 12, a quadrupole mass filter/analyser 13 and may include other elements such as a collision cell (not shown), a further quadrupole mass filter/analyser together with an ion detector (not shown) or a time of flight analyser (not shown).
- Fig. 3 illustrates an embodiment of the present invention wherein hexapole ion guide 6 has been replaced with an ion tunnel 15 according to the preferred embodiment.
- the other components of the mass spectrometer are substantially the same as described in relation to Fig. 2 and hence will not be described again.
- the ion tunnel 15 exhibits an improved transmission efficiency of approximately 75% compared with using hexapole ion guide 6 and the ion tunnel 15 does not suffer from as narrow a m/z bandpass transmission efficiency as is reported with ion funnels.
- the reference potential of the ion tunnel 15 is preferably maintained at 0-2 V dc above the dc potential of the wall forming the differential pumping aperture 11 which is preferably either at ground (0 V dc) or around 40-240 V dc depending upon the mass analyser used.
- the wall forming differential pumping aperture 11 may, of course, be maintained at other dc potentials.
- the hexapole ion guide 9 may be replaced by an ion tunnel 15' with hexapole ion guide 6 being maintained.
- Fig. 4 shows a particularly preferred embodiment of the present invention wherein both hexapole ion guides 6,9 have been replaced with ion tunnels 15,15'.
- the ion tunnels 15,15' are about 13 cm in length and preferably comprise approximately 85 ring electrodes.
- the ion tunnel 15 in vacuum chamber 18 is preferably maintained at a pressure ⁇ 1 mbar and is supplied with an rf-voltage at a frequency - 1 MHz
- the ion tunnel 15' in vacuum chamber 19 is preferably maintained at a pressure of 10 -3 -10 -2 mbar and is supplied with an rf-voltage at a frequency - 2 MHz.
- Rf frequencies of 800 kHz - 3 MHz could also be used for both ion tunnels 15,15' according to further embodiments of the present invention.
- the ion tunnel 15' exhibits an improved transmission efficiency of approximately 25%, and hence the combination of ion tunnels 15,15' exhibit an improved transmission efficiency of approximately 100% compared with using hexapole ion guide 6 in combination with hexapole ion guide 9.
- Figs. 5 and 6 show a particularly preferred embodiment of the present invention.
- the AC-only ion guide comprises two interleaved comb-like arrangements of electrodes.
- Each comb comprises a plurality of electrodes 15a;15b, each electrode 15a;15b having an aperture.
- One of the combs is shown in more detail in Fig. 5 .
- the comb comprises a longitudinally extending bar or spine from which a number of electrodes 15a;15b depend therefrom.
- the electrodes 15a;15b are integral with the bar or spine.
- Each electrode 15a;15b preferably has a substantially circular aperture. However, as can be seen from Fig.
- each electrode 15a;15b in cross-section is preferably a truncated circular shape.
- Fig. 6 shows in more detail how the two combs are interleaved. Various insulating rings are also shown which help to hold the assembly together.
- the comb like arrangement of electrodes 15a;15b may be provided in input vacuum chamber 18 and/or intermediate vacuum chamber 19. For the avoidance of any doubt, the arrangements shown in Figs. 5 and 6 are intended to fall within the scope of the claims.
Landscapes
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Other Investigation Or Analysis Of Materials By Electrical Means (AREA)
- Electron Tubes For Measurement (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
- Analysing Materials By The Use Of Radiation (AREA)
Abstract
Description
- The present invention relates to mass spectrometers and methods of mass spectrometry.
- Ion guides comprising rf-only multipole rod sets such as quadrupoles, hexapoles and octopoles are well known.
- An alternative type of ion guide known as an "ion funnel" has recently been proposed by Smith and coworkers at Pacific Northwest National Laboratory. An ion funnel comprises a stack of ring electrodes of constant external diameter but which have progressively smaller internal apertures. A dc voltage/potential gradient is applied along the length of the ion guide in order to urge ions through the ion funnel which would otherwise act as an ion mirror.
- A variant of the standard ion funnel arrangement is disclosed in Anal. Chem. 2000, 72, 2247-2255 and J. Am. Soc. Mass Spectrom. 2000, 11, 19-23 (Belov) and comprises an initial drift section comprising ring electrodes having constant internal diameters and a funnel section comprising ring electrodes having uniformly decreasing internal diameters. A dc voltage gradient is applied across both sections in order to urge ions through the ion funnel.
- Ion funnels have not been successfully employed in commercial mass spectrometers to date.
- One reason for this may be that ion funnels suffer from a narrow bandpass transmission efficiency i.e. the ion funnel may, for example, only efficiently transmit ions having mass to charge ratios ("m/z") falling within a narrow range e.g. 100 < m/z < 200. Reference is made, for example, to Figs. 5A and 5B of Anal. Chem. 1998, 70, 4111-4119 wherein experimental results are presented comparing observed mass spectra obtained using an ion funnel with that obtained using a conventional ion guide. The experimental results show that both relatively low m/z and relatively high m/z ions fail to be transmitted by the ion funnel. Reference is also made to pages 2249 and 2250 of Anal. Chem 2000, 72, 2247-2255 which similarly recognises that ion funnels suffer from an undesirably narrow m/z transmission window.
- Another reason may be that ion funnel ion guides require both an rf voltage and a dc voltage gradient to be applied to the ring electrodes. However, the design and manufacture of a reliable power supply capable of supplying both an rf voltage and a dc voltage gradient which is decoupled from the rf voltage is a non-trivial matter and increases the overall manufacturing cost of the mass spectrometer.
-
US-5818055 discloses a method and device for injection of ions into an ion trap. - It is therefore desired to provide an improved ion guide.
- According to an aspect of the present invention there is provided a mass spectrometer as claimed in
claim 1. - The preferred embodiment comprises a plurality of electrodes wherein most if not all of the electrodes have apertures which are substantially the same size. The apertures are preferably circular in shape, and the outer circumference of the electrodes may also be circular. In one embodiment the electrodes may comprise ring or annular electrodes. However, the outer circumference of the electrodes does not need to be circular and embodiments of the present invention are contemplated wherein the outer profile of the electrodes may take on other shapes. The preferred embodiment wherein the internal apertures of each of the electrodes are either identical or substantially similar is referred to hereinafter as an "ion tunnel" in contrast to ion funnels which have ring electrodes with internal apertures which become progressively smaller in size.
- One advantage of the preferred embodiment is that the ion guide does not suffer from a narrow or limited mass to charge ratio transmission efficiency which appears to be inherent with ion funnel arrangements.
- Another advantage of the preferred embodiment is that a dc voltage gradient is not and does not need to be applied to the ion guide. The resulting power supply for the ion guide can therefore be significantly simplified compared with that required for an ion funnel thereby saving costs and increasing reliability.
- An additional advantage of the preferred embodiment is that it has been found to exhibit an approximately 75% improvement in ion transmission efficiency compared with a conventional multipole, e.g. hexapole, ion guide. The reasons for this enhanced ion transmission efficiency are not fully understood, but it is thought that the ion tunnel may have a greater acceptance angle and a greater acceptance area than a comparable multipole rod set ion guide.
- The preferred ion guide therefore represents a significant improvement over other known ion guides.
- Various types of ion optical devices other than an ion tunnel ion guide are known including multipole rod sets, Einzel lenses, segmented multipoles, short (solid) quadrupole pre/post filter lenses ("stubbies"), 3D quadrupole ion traps comprising a central doughnut shaped electrode together with two concave end cap electrodes, and linear (2D) quadrupole ion traps comprising a multipole rod set with entrance and exit ring electrodes. However, such devices are not intended to fall within the scope of the present invention.
- According to the preferred embodiment, the input vacuum chamber is arranged to be maintained at a relatively high pressure i.e. at least a few mbar. According to an embodiment, the input vacuum chamber may be arranged to be maintained at a pressure above a minimum value of 0.1 mbar and less than or equal to a maximum value such as 20 or 30 mbar.
- Embodiments of the present invention are also contemplated, wherein if the AC-only ion guide is considered to have a length L and is maintained in the input vacuum chamber at a pressure P, then the pressure-length product p x L is selected from the group comprising: (i) ≥ 1 mbar cm; (ii) ≥ 2 mbar cm; (iii) ≥ 5 mbar cm; (iv) ≥ 10 mbar cm; (v) ≥ 15 mbar cm; (vi) ≥ 20 mbar cm; (vii) ≥ 25 mbar cm; (viii) ≥ 30 mbar cm; (ix) ≥ 40 mbar cm; (x) ≥ 50 mbar cm; (xi) ≥ 60 mbar cm; (xii) ≥ 70 mbar cm; (xiii) ≥ 80 mbar cm; (xiv) ≥ 90 mbar cm; (xv) ≥ 100 mbar cm; (xvi) ≥ 110 mbar cm; (xvii) ≥ 120 mbar cm; (xviii) ≥ 130 mbar cm; (xix) ≥ 140 mbar cm; (x%) ≥ 150 mbar cm; (xxi) ≥ 160 mbar cm; (xxii) ≥ 170 mbar cm; (xxiii) ≥ 180 mbar cm; (xxiv) ≥ 190 mbar cm; and (xxv) ≥ 200 mbar cm.
- The electrodes are preferably relatively thin e.g. ≤ 2 mm, further preferably ≤ 1 mm, further preferably 0.5 ± 0.2 mm, further preferably 0.7 ± 0.1 mm thick. According to a particularly preferred embodiment the electrodes have a thickness within the range 0.5-0.7 mm in contrast to multipole rod sets which are typically > 10 cm long.
- Each, or at least a majority of the electrodes forming the AC-only ion guide may comprise either a plate having an aperture therein, or a wire or rod bent to form a closed ring or a nearly closed ring. The outer profile of the electrodes may or may not be circular.
- Preferably, alternate electrodes are connected together and to one of the output connections of a single AC generator.
- The AC-only ion guide preferably comprises at least 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 60, 70, 80, 90 or 100 electrodes.
- The electrodes forming the AC-only ion guide may have internal diameters or dimensions selected from the group comprising: (i) ≤ 5.0 mm; (ii) ≤ 4.5 mm; (iii) ≤ 4.0 mm; (iv) ≤ 3.5 mm; (v) ≤ 3.0 mm; (vi) ≤ 2.5 mm; (vii) 3.0 ± 0.5 mm; (viii) ≤ 10.0 mm; (ix) ≤ 9.0 mm; (x) ≤ 8.0 mm; (x) ≤ 7.0 mm; (xii) ≤ 6.0 mm; (xiii) 5.0 t 0.5 mm; and (xiv) 4-6 mm.
- The length of the AC-only ion guide may be selected from the group comprising: (i) ≥ 100 mm; (ii) ≥ 120 mm; (iii) ≥ 150 mm; (iv) 130 ± 10 mm; (v) 100-150 mm; (vi) ≤ 160 mm; (vii) ≤ 180 mm; (viii) ≤ 200 mm; (ix) 130-150 mm; (x) 120-180 mm; (xi) 120-140 mm; (xii) 130 mm ± 5, 10, 15, 20, 25 or 30 mm; (xiii) 50-300 mm; (xiv) 150-300 mm; (xv) ≥ 50 mm; (xvi) 50-100 mm; (xvii) 60-90 mm; (xviii) ≥ 75 mm; (xix) 50-75 mm; and (xx) 75-100 mm.
- An intermediate vacuum chamber is disposed between the input vacuum chamber and the analyzer vacuum chamber, the intermediate vacuum chamber comprising an AC-only ion guide for transmitting ions through the intermediate vacuum chamber. The AC-only ion guide arranged in the intermediate vacuum chamber preferably comprises a plurality of electrodes having apertures, the apertures being aligned so that ions travel through them as they are transmitted by the ion guide. At least one further differential pumping apertured electrode is provided through which ions may pass. The further differential pumping apertured electrode is disposed between the vacuum chambers to allow the intermediate vacuum chamber to be maintained at a lower pressure than the input vacuum chamber, and the analyzer vacuum chamber to be maintained at a lower pressure than the intermediate vacuum chamber. An alternating current (AC) generator is connected to an intermediate chamber reference potential for providing AC potentials to the AC-only ion guide in the intermediate vacuum chamber.
- Preferably, at least 90%, and preferably 100%, of the apertures of the electrodes forming the AC-only ion guide in the intermediate vacuum chamber are substantially the same size, and at least 90%, and preferably 100%, of the plurality of the electrodes forming the AC-only ion guide in the intermediate vacuum chamber are connected to the AC generator connected to the intermediate chamber reference potential in such a way that at any instant during an AC cycle of the output of the AC generator, adjacent ones of the electrodes forming the AC-only ion guide arranged in the intermediate vacuum chamber are supplied respectively with approximately equal positive and negative potentials relative to the intermediate chamber reference potential.
- Preferably, the AC-only ion guide in the intermediate vacuum chamber comprises at least 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 60, 70, 80, 90, or 100 electrodes.
- Preferably, the intermediate vacuum chamber is arranged to be maintained at a pressure selected from the group comprising: (i) 10-3-10-2 mbar; (ii) ≥ 2 x 10-3 mbar; (iii) ≥ 5 x 10-3 mbar; (iv) ≤ 10-2 mbar; (v) 10-3-5 x 10-3 mbar; and (vi) 5 x 10-3-10-2 mbar.
- Preferably, the electrodes forming the AC-only ion guide in the intermediate vacuum chamber have internal diameters or dimensions selected from the group comprising: (i) ≤ 5.0 mm; (ii) ≤ 4.5 mm; (iii) ≤ 4.0 mm; (iv) ≤ 3.5 mm; (v) ≤ 3.0 mm; (vi) ≤ 2.5 mm; (vii) 3.0 ± 0.5 mm; (viii) ≤ 10.0 mm; (ix) ≤ 9.0 mm; (x) ≤ 8.0 mm; (xi) ≤ 7.0 mm; (xii) ≤ 6.0 mm; (xiii) 5.0 ± 0.5 mm; and (xiv) 4-6 mm.
- In one embodiment the individual electrodes in the AC-only ion guide in the input vacuum chamber and/or the AC-only ion guide in the intermediate vacuum chamber preferably have a substantially circular aperture having a diameter selected from the group comprising: (i) 0.5-1.5 mm; (ii) 1.5-2.5 mm; (iii) 2.5-3.5 mm; (iv) 3.5-4.5 mm; (v) 4.5-5.5 mm; (vi) 5.5-6.5 mm; (vii) 6.5-7.5 mm; (viii) 7.5-8.5 mm; (ix) 8.5-9.5 mm; (x) 9.5-10.5 mm; and (xi) <10mm.
- Preferably, the length of the ion guide in the intermediate vacuum chamber is selected from the group comprising: (i) ≥ 100 mm; (ii) ≥ 120 mm; (iii) ≥ 150 mm; (iv) 130 ± 10 mm; (v) 100-150 mm; (vi) ≤ 160 mm; (vii) ≤ 180 mm; (viii) ≤ 200 mm; (ix) 130-150 mm; (x) 120-180 mm; (xi) 120-140 mm; (xii) 130 mm ± 5, 10, 15, 20, 25 or 30 mm; (xiii) 50-300 mm; (xiv) 150-300 mm; (xv) ≥ 50 mm; (xvi) 50-100 mm; (xvii) 60-90 mm; (xviii) ≥ 75 mm; (xix) 50-75 mm; and (xx) 75-100 mm.
- Preferably, the ion source is an atmospheric pressure ion source.
- Preferably, the ion source is a continuous ion source.
- An Electrospray ("ES") ion source or an Atmospheric Pressure Chemical Ionisation ("APCI") ion source is particularly preferred. However, other embodiments are also contemplated wherein the ion source is either an Inductively Coupled Plasma ("ICP") ion source or a Matrix Assisted Laser Desorption Ionisation ("MALDI") ion source at low vacuum or at atmospheric pressure.
- Preferably, the ion mass analyser is selected from the group comprising: (i) a time-of-flight mass analyser, preferably an orthogonal time of flight mass analyser; (ii) a quadrupole mass analyser; and (iii) a quadrupole ion trap.
- The AC-only ion guide comprises two interleaved comb arrangements, each comb arrangement comprising a longitudinally extending bar or spine having a plurality of electrodes having apertures depending therefrom.
- Preferably, the input vacuum chamber has a length and the combs arrangements extend at least x% of the length, x% selected from the group comprising: (i) ≥ 50%; (ii) ≥ 60%; (iii) ≥ 70%; (iv) ≥ 80%; (v) ≥ 90%; and (vi) ≥ 95%.
- According to a another aspect of the present invention, there is provided a method of mass spectrometry as claimed in claim 25.
- Various embodiments of the present invention will now be described, by way of example only, and with reference to the accompanying drawings in which:
-
Fig. 1 shows a preferred ion tunnel arrangement; -
Fig. 2 shows a conventional mass spectrometer with an atmospheric pressure ion source and two rf hexapole ion guides disposed in separate vacuum chambers; -
Fig. 3 shows an embodiment of the present invention wherein one of the hexapole ion guides has been replaced with an ion tunnel; -
Fig. 4 shows another embodiment of the present invention wherein both hexapole ion guides have been replaced with ion tunnels; -
Fig. 5 shows a comb arrangement; and -
Fig. 6 shows a particularly preferred embodiment comprising two interleaved comb-like arrangements. - As shown in
Fig. 1 , apreferred ion tunnel 15 comprises a plurality ofelectrodes electrodes electrodes -
Adjacent electrodes ring electrodes 15a may be connected to the 0°phase supply 16a, and the second, fourth, sixth etc.ring electrodes 15b may be connected to the 180°phase supply 16b. In one embodiment the AC power supply may be a RF power supply. However, the present invention is not intended to be limited to RF frequencies. Furthermore, "AC" is intended to mean simply that the waveform alternates and hence embodiments of the present invention are also contemplated wherein non-sinusoidal waveforms including square waves are provided. Ions from an ion source pass through theion tunnel 15 and are efficiently transmitted by it. - In contrast to ion funnels, the dc reference potential about which the AC signal oscillates is substantially the same for each electrode. Unlike ion traps, blocking dc potentials are not applied to either the entrance or exit of the
ion tunnel 15. -
Fig. 2 shows a conventional mass spectrometer. An Electrospray ("ES")ion source 1 or an Atmospheric Pressure Chemical lonisation ("APCI") 1,2 ion source emits ions which enter avacuum chamber 17 pumped by a rotary ormechanical pump 4 via a sample cone 3 and a portion of the gas and ions passes through adifferential pumping aperture 21 preferably maintained at 50-120V into avacuum chamber 18 housing an rf-onlyhexapole ion guide 6.Vacuum chamber 18 is pumped by a rotary ormechanical pump 7. Ions are transmitted by the rf-onlyhexapole ion guide 6 through thevacuum chamber 18 and pass through adifferential pumping aperture 8 into afurther vacuum chamber 19 pumped by a turbo-molecular pump 10. Thisvacuum chamber 19 houses another rf-onlyhexapole ion guide 9. Ions are transmitted by rf-onlyhexapole ion guide 9 throughvacuum chamber 19 and pass throughdifferential pumping aperture 11 into a yetfurther vacuum chamber 20 which is pumped by a turbo-molecular pump 14.Vacuum chamber 20 houses a prefilter rod set 12, a quadrupole mass filter/analyser 13 and may include other elements such as a collision cell (not shown), a further quadrupole mass filter/analyser together with an ion detector (not shown) or a time of flight analyser (not shown). -
Fig. 3 illustrates an embodiment of the present invention whereinhexapole ion guide 6 has been replaced with anion tunnel 15 according to the preferred embodiment. The other components of the mass spectrometer are substantially the same as described in relation toFig. 2 and hence will not be described again. Theion tunnel 15 exhibits an improved transmission efficiency of approximately 75% compared with usinghexapole ion guide 6 and theion tunnel 15 does not suffer from as narrow a m/z bandpass transmission efficiency as is reported with ion funnels. An rf-voltage is applied to the electrodes and the reference potential of theion tunnel 15 is preferably maintained at 0-2 V dc above the dc potential of the wall forming thedifferential pumping aperture 11 which is preferably either at ground (0 V dc) or around 40-240 V dc depending upon the mass analyser used. However, the wall formingdifferential pumping aperture 11 may, of course, be maintained at other dc potentials. - In another less preferred (unillustrated) embodiment, the
hexapole ion guide 9 may be replaced by an ion tunnel 15' withhexapole ion guide 6 being maintained. -
Fig. 4 shows a particularly preferred embodiment of the present invention wherein both hexapole ion guides 6,9 have been replaced withion tunnels 15,15'. Theion tunnels 15,15' are about 13 cm in length and preferably comprise approximately 85 ring electrodes. Theion tunnel 15 invacuum chamber 18 is preferably maintained at a pressure ≥ 1 mbar and is supplied with an rf-voltage at a frequency - 1 MHz, and the ion tunnel 15' invacuum chamber 19 is preferably maintained at a pressure of 10-3-10-2 mbar and is supplied with an rf-voltage at a frequency - 2 MHz. Rf frequencies of 800 kHz - 3 MHz could also be used for bothion tunnels 15,15' according to further embodiments of the present invention. - The ion tunnel 15' exhibits an improved transmission efficiency of approximately 25%, and hence the combination of
ion tunnels 15,15' exhibit an improved transmission efficiency of approximately 100% compared with usinghexapole ion guide 6 in combination withhexapole ion guide 9. -
Figs. 5 and6 show a particularly preferred embodiment of the present invention. The AC-only ion guide comprises two interleaved comb-like arrangements of electrodes. Each comb comprises a plurality ofelectrodes 15a;15b, eachelectrode 15a;15b having an aperture. One of the combs is shown in more detail inFig. 5 . As can be seen, the comb comprises a longitudinally extending bar or spine from which a number ofelectrodes 15a;15b depend therefrom. Theelectrodes 15a;15b are integral with the bar or spine. Eachelectrode 15a;15b preferably has a substantially circular aperture. However, as can be seen fromFig. 5 , in cross-section the outer profile of eachelectrode 15a;15b is preferably a truncated circular shape.Fig. 6 shows in more detail how the two combs are interleaved. Various insulating rings are also shown which help to hold the assembly together. The comb like arrangement ofelectrodes 15a;15b may be provided ininput vacuum chamber 18 and/orintermediate vacuum chamber 19. For the avoidance of any doubt, the arrangements shown inFigs. 5 and6 are intended to fall within the scope of the claims.
Claims (30)
- A mass spectrometer comprising:an ion source (1) for producing ions;an input vacuum chamber (18) comprising at least one AC ion guide for transmitting said ions wherein adjacent electrodes forming said AC ion guide are connected to opposite phases of an AC power supply;an analyser vacuum chamber (20) comprising a mass analyser (13) disposed to receive ions after they have been transmitted by said AC ion guide;an intermediate vacuum chamber (19) disposed between said input vacuum chamber (18) and said analyser vacuum chamber (20), wherein said intermediate vacuum chamber (19) comprises an AC ion guide for transmitting ions through said intermediate vacuum chamber (19);at least one differential pumping apertured electrode (8) through which ions may pass, said at least one differential pumping apertured electrode (8) being disposed between said input vacuum chamber (18) and said intermediate vacuum chamber (19) to permit said intermediate vacuum chamber (19) to be maintained at a lower pressure than said input vacuum chamber (18); andat least one further differential pumping apertured electrode (11) through which ions may pass disposed between said intermediate vacuum chamber (19) and said analyser vacuum chamber (20) to allow said analyser vacuum chamber (20) to be maintained at a lower pressure than said intermediate vacuum chamber (19);characterised in that:said AC ion guide arranged in said input vacuum chamber (18) comprises two interleaved comb arrangements, each said comb arrangement comprising a longitudinally extending bar or spine having a plurality of electrodes having apertures depending therefrom, wherein said electrodes are integral with said bar or spine.
- A mass spectrometer as claimed in claim 1, wherein at least 90% or 100% of said apertures are substantially the same size.
- A mass spectrometer as claimed in claim 1 or 2, wherein said plurality of electrodes forming said AC ion guide arranged in said input vacuum chamber (18) are connected to an AC generator in such a way that at any instant during an AC cycle of the output of said AC generator, adjacent ones of said electrodes are supplied respectively with approximately equal positive and negative potentials relative to an input chamber reference potential.
- A mass spectrometer as claimed in any preceding claim, wherein said input vacuum chamber (18) has a length and said comb arrangements extend at least x% of said length, x% selected from the group consisting of: (i) ≥ 50%; (ii) ≥ 60%; (iii) ≥ 70%; (iv) ≥ 80%; (v) ≥ 90%; and (vi) ≥ 95%.
- A mass spectrometer as claimed in any preceding claim, wherein alternate ones of said electrodes are connected to each other and to one of the output connections of a single AC generator.
- A mass spectrometer as claimed in any preceding claim, wherein the AC ion guide arranged in said input vacuum chamber (18) comprises at least 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 60, 70, 80, 90, or 100 electrodes.
- A mass spectrometer as claimed in any preceding claim, wherein said electrodes have internal diameters or dimensions selected from the group consisting of: (i) ≤ 5.0 mm; (ii) ≤ 4.5 mm; (iii): ≤ 4.0 mm; (iv) ≤ 3.5 mm; (v) ≤3.0 mm; (vi):s 2.5 mm; (vii) 3.0 ± 0.5 mm; (viii) ≤ 10.0 mm; (ix) ≤ 9.0 mm; (x) ≤ 8.0 mm; (xi) ≤ 7.0 mm; (xii) ≤ 6.0 mm; (xiii) 5.0 ± 0.5 mm; and (xiv) 4-6 mm.
- A mass spectrometer as claimed in any preceding claim, wherein the length of said AC ion guide arranged in said input vacuum chamber (18) is selected from the group consisting of: (i) ≥ 100 mm; (ii) ≥ 120 mm; (iii) ≥ 150 mm; (iv) 130 ± 10 mm; (v) 100-150 mm; (vi) ≤ 160 mm; (vii) ≤ 180 mm; (viii) ≤ 200 mm; (ix) 130-150 mm; (x) 120-180 mm; (xi) 120-140 mm; (xii) 130 mm ± 5, 10, 15, 20, 25 or 30 mm; (xiii) 50-300 mm; (xiv) 150-300 mm; (xv) ≥ 50 mm; (xvi) 50-100 mm; (xvii) 60-90 mm; (xviii) ≥ 75 mm; (xix) 50-75 mm; (xx) 75-100 mm; (xxi) 150-200 mm; (xxii) ≥ 200 mm; and (xxiii) 50-200 mm.
- A mass spectrometer as claimed in any preceding claim, wherein said AC ion guide arranged in said intermediate vacuum chamber (19) comprises a plurality of electrodes having apertures, the apertures being aligned so that ions travel through them as they are transmitted by said AC ion guide in said intermediate vacuum chamber (19);
wherein said mass spectrometer further comprises an alternating current (AC) generator connected to an intermediate chamber reference potential for providing AC potentials to said AC ion guide in said intermediate vacuum chamber (19). - A mass spectrometer as claimed in claim 9, wherein at least 90% or 100% of the apertures of the electrodes forming said AC ion guide in said intermediate vacuum chamber (19) are substantially the same size; and
at least 90% or 100% of said plurality of the electrodes forming said AC ion guide in said intermediate vacuum chamber (19) are connected to the AC generator connected to said intermediate chamber reference potential in such a way that at any instant during an AC cycle of the output of the AC generator, adjacent ones of said electrodes forming said AC ion guide arranged in said intermediate vacuum chamber (19) are supplied respectively with approximately equal positive and negative potentials relative to said intermediate chamber reference potential. - A mass spectrometer as claimed in claim 9 or 10, wherein the AC ion guide in said intermediate vacuum chamber (19) comprises at least 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 60, 70, 80, 90, or 100 electrodes.
- A mass spectrometer as claimed in any of claims 9, 10 or 11, wherein said intermediate vacuum chamber (19) is arranged to be maintained at a pressure selected from the group consisting of: (i) 10-3-10-2 mbar; (ii) ≥ 2 x 10-3 mbar; (iii) ≥ 5 x10-3 mbar; (iv) ≤ 10-2 mbar; (v) 10-3-5 x 10-3 mbar; and (vi) 5 x 10-3-10-2 mbar.
- A mass spectrometer as claimed in any of claims 9-12, wherein electrodes forming said AC ion guide in said intermediate vacuum chamber (19) have internal diameters or dimensions selected from the group consisting of: (i) ≤ 5.0 mm; (ii) ≤ 4.5 mm; (iii) ≤ 4.0 mm; (iv) ≤ 3.5 mm; (v) ≤ 3.0 mm; (vi) ≤ 2.5 mm; (vii) 3.0 ± 0.5 mm; (viii) ≤ 10.0 mm; (ix) ≤ 9.0 mm; (x) ≤ 8.0 mm; (xi) ≤ 7.0 mm; (xii) ≤ 6.0 mm; (xiii) 5.0 ± 0.5 mm; and (xiv) 4-6 mm.
- A mass spectrometer as claimed in any of claims 9-13, wherein the length of said AC ion guide in said intermediate vacuum chamber (19) is selected from the group consisting of: (i) ≥ 100 mm; (ii) ≥ 120 mm; (iii) ≥ 150 mm; (iv) 130 ± 10 mm; (v) 100-150 mm; (vi) ≤ 160 mm; (vii) ≤ 180 mm; (viii) ≤ 200 mm; (ix) 130-150 mm; (x) 120-180 mm; (xi) 120-140 mm; (xii) 130 mm ± 5, 10, 15, 20, 25 or 30 mm; (xiii) 50-300 mm; (xiv) 150-300 mm; (xv) ≥ 50 mm; (xvi) 50-100 mm; (xvii) 60-90 mm; (xviii) ≥ 75 mm; (xix) 50-75 mm; (xx) 75-100 mm; (xxi) 150-200 mm; (xxii) ≥ 200 mm; and (xxiii) 50-200 mm.
- A mass spectrometer as claimed in any preceding claim, wherein said ion source (1) is an atmospheric pressure ion source.
- A mass spectrometer as claimed in any preceding claim, wherein said ion source (1) is a continuous ion source.
- A mass spectrometer as claimed in claim 15 or 16, wherein said ion source (1) is an Electrospray ("ES") ion source or an Atmospheric Pressure Chemical Ionisation ("APCI") ion source.
- A mass spectrometer as claimed in claim 15 or 16, wherein said ion source (1) is an Inductively Coupled Plasma ("ICP") ion source.
- A mass spectrometer as claimed in any of claims 1-14, wherein said ion source (1) is a Matrix Assisted Laser Desorption Ionisation ("MALDI") ion source.
- A mass spectrometer as claimed in any preceding claim, wherein said mass analyser is selected from the group consisting: (i) a Time of Flight mass analyser, (ii) an orthogonal Time of Flight mass analyser; (iii) a quadrupole mass analyser; and (iv) a quadrupole ion trap..
- A mass spectrometer as claimed in any preceding claim, wherein said input vacuum chamber (18) is arranged to be maintained at a pressure selected from the group consisting of: (i) ≥ 0.1 mbar; (ii) ≥ 0.5 mbar; (iii) ≥ 0.7 mbar; (iv) ≥ 1.0 mbar; (v) ≥ 1.3 mbar; (vi) ≥ 1.5 mbar; (vii) ≥ 2.0 mbar; (viii) ≥ 2.5 mbar; (ix) ≥ 3.0 mbar; (x) ≥ 3.5 mbar; (xi) ≥ 4.0 mbar; (xii) ≥ 4.5 mbar; (xiii) ≥ 5.0 mbar; (xiv) ≥ 6.0 mbar; (xv) ≥ 7.0 mbar; (xvi) ≥ 8.0 mbar; (xvii) ≥ 9.0 mbar; (xviii) ≥ 10.0 mbar; (xix) 1-5 mbar; (xx) 1-2 mbar; and (xxi) 0.5-1.5 mbar.
- A mass spectrometer as claimed in any preceding claim, wherein said input vacuum chamber (18) is arranged to be maintained at a pressure selected from the group consisting of: (i) ≤ 20 mbar; and (ii) ≤ 30 mbar.
- A mass spectrometer as claimed in any preceding claim, wherein if the AC ion guide arranged in said input vacuum chamber (18) has a length L and is maintained in the input vacuum chamber (18) at a pressure P, then the pressure-length product p x L is selected from the group consisting of: (i) ≥ 1 mbar cm; (ii) ≥ 2 mbar cm; (iii) ≥ 5 mbar cm; (iv) ≥ 10 mbar cm; (v) ≥ 15 mbar cm; (vi) ≥ 20 mbar cm; (vii) ≥ 25 mbar cm; (viii) ≥ 30 mbar cm; (ix) ≥ 40 mbar cm; (x) ≥ 50 mbar cm; (xi) ≥ 60 mbar cm; (xii) ≥ 70 mbar cm; (xiii) ≥ 80 mbar cm; (xiv) ≥ 90 mbar cm; (xv) ≥ 100 mbar cm; (xvi) ≥ 110 mbar cm; (xvii) ≥ 120 mbar cm; (xviii) ≥ 130 mbar cm; (xix) ≥ 140 mbar cm; (xx) ≥ 150 mbar cm; (xxi) ≥ 160 mbar cm; (xxii) ≥ 170 mbar cm; (xxiii) ≥ 180 mbar cm; (xxiv) ≥ 190 mbar cm; and (xxv) ≥ 200 mbar cm.
- A mass spectrometer as claimed in any preceding claim, wherein the electrodes forming the AC ion guide arranged in said input vacuum chamber (18) have a thickness selected from the group consisting of: (i) ≤ 2 mm; (ii) ≤ 1 mm; (iii) 0.5 ± 0.2 mm; (iv) 0.7 ± 0.1 mm; and (v) 0.5-0.7 mm.
- A method of mass spectrometry, comprising:producing ions from an ion source;transmitting at least some of said ions through an input vacuum chamber (18) comprising at least one AC ion guide for transmitting said ions, wherein adjacent electrodes forming said AC ion guide are connected to opposite phases of an AC power supply;passing said ions to an analyser vacuum chamber (20) comprising a mass analyser (13) disposed to receive ions after they have been transmitted by said AC ion guide;providing an intermediate vacuum chamber (19) disposed between said input vacuum chamber (18) and said analyser vacuum chamber (20), said intermediate vacuum chamber (19) comprising an AC ion guide for transmitting ions through said intermediate vacuum chamber (19);providing at least one differential pumping apertured electrode (8) through which ions may pass, said at least one differential pumping apertured electrode (8) being disposed between said input vacuum chamber (18) and said intermediate vacuum chamber (19) to permit said intermediate vacuum chamber (19) to be maintained at a lower pressure than said input vacuum chamber (18); andproviding at least one further differential pumping apertured electrode (11) through which ions may pass disposed between said intermediate vacuum chamber (19) and said analyser vacuum chamber (20) to allow said analyser vacuum chamber (20) to be maintained at a lower pressure than said intermediate vacuum chamber (19);characterised in that:said step of transmitting at least some of said ions through said input vacuum chamber (18) comprises transmitting said ions through said AC ion guide comprising two interleaved comb arrangements, each said comb arrangement comprising a longitudinally extending bar or spine having a plurality of electrodes having apertures depending therefrom, wherein said electrodes are integral with said bar or spine.
- A method as claimed in claim 25, further comprising maintaining said input vacuum chamber at a pressure selected from the group consisting of: (i) ≥ 0.1 mbar; (ii) ≥ 0.5 mbar; (iii) ≥ 0.7 mbar; (iv) ≥ 1.0 mbar; (v) ≥ 1.3 mbar; (vi) ≥ 1.5 mbar; (vii) ≥ 2.0 mbar; (viii) ≥ 2.5 mbar; (ix) ≥ 3.0 mbar; (x) ≥ 3.5 mbar; (xi) ≥ 4.0 mbar; (xii) ≥ 4.5 mbar; (xiii) ≥ 5.0 mbar; (xiv) ≥ 6.0 mbar; (xv) ≥ 7.0 mbar; (xvi) ≥ 8.0 mbar; (xvii) ≥ 9.0 mbar; (xviii) ≥ 10.0 mbar; (xix) 1-5 mbar; (xx) 1-2 mbar; and (xxi) 0.5-1.5 mbar.
- A method as claimed in claim 25 or 26, further comprising maintaining said input vacuum chamber (18) at a pressure selected from the group consisting of: (i) ≤ 20 mbar; and (ii) ≤ 30 mbar.
- A method as claimed in claims 25, 26 or 27, wherein said AC ion guide arranged in said intermediate vacuum chamber (19) comprises a plurality of electrodes having apertures, the apertures being aligned so that ions travel through them as they are transmitted by said ion guide;
said method further comprising providing an alternating current (AC) generator connected to an intermediate chamber reference potential for providing AC potentials to the AC ion guide in said intermediate vacuum chamber (19). - A method as claimed in claim 28, further comprising maintaining said intermediate vacuum chamber (19) at a pressure selected from the group consisting of: (i) 10-3-10-2 mbar; (ii) (i) ≥ 2 x 10-3 mbar; (iii) ≥ 5 x 10-3 mbar; (iv) ≤ 10-2 mbar; (v) 10-3-5 x 10-3 mbar; and (vi) 5 x 10-2 mbar.
- A method as claimed in any of claims 25-29, further comprising maintaining the AC ion guide having a length L in the input vacuum chamber (18) at a pressure P, wherein the pressure-length product p x L is selected from the group consisting of: (i) ≥ 1 mbar cm; (ii) ≥ 2 mbar cm; (iii) ≥ 5 mbar cm; (iv) ≥ 10 mbar cm; (v) ≥ 15 mbar cm; (vi) ≥ 20 mbar cm; (vii) ≥ 25 mbar cm; (viii) ≥ 30 mbar cm; (ix) ≥ 40 mbar cm; (x) ≥ 50 mbar cm; (xi) ≥ 60 mbar cm; (xii) ≥ 70 mbar cm; (xiii) ≥ 80 mbar cm; (xiv) ≥ 90 mbar cm; (xv) ≥ 100 mbar cm; (xvi) ≥ 110 mbar cm; (xvii) ≥ 120 mbar cm; (xviii) ≥ 130 mbar cm; (xix) ≥ 140 mbar cm; (xx) ≥ 150 mbar cm; (xxi) ≥ 160 mbar cm; (xxii) ≥ 170 mbar cm; (xxiii) ≥ 180 mbar cm; (xxiv) ≥ 190 mbar cm; and (xxv) ≥ 200 mbar cm.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP20100183535 EP2302661A1 (en) | 2000-11-29 | 2001-11-29 | Mass spectrometer comprising an ion tunnel ion guide, method of mass spectrometry |
Applications Claiming Priority (9)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB0029088 | 2000-11-29 | ||
GBGB0029088.2A GB0029088D0 (en) | 2000-11-29 | 2000-11-29 | Ion tunnel |
GBGB0109760.9A GB0109760D0 (en) | 2000-11-29 | 2001-04-20 | Mass spectrometers and methods of mass spectrometry |
GB0109760 | 2001-04-20 | ||
GB0110149A GB0110149D0 (en) | 2000-11-29 | 2001-04-25 | Mass spectrometers and methods of mass spectrometry |
GB0110149 | 2001-04-25 | ||
GB0120028 | 2001-08-16 | ||
GBGB0120028.6A GB0120028D0 (en) | 2000-11-29 | 2001-08-16 | Mass spectrometers and methods of mass spectrometry |
EP01310026A EP1215712B1 (en) | 2000-11-29 | 2001-11-29 | Mass spectrometer and methods of mass spectrometry |
Related Parent Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP01310026A Division EP1215712B1 (en) | 2000-11-29 | 2001-11-29 | Mass spectrometer and methods of mass spectrometry |
EP01310026.8 Division | 2001-11-29 |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP10183535.3 Division-Into | 2010-09-30 |
Publications (3)
Publication Number | Publication Date |
---|---|
EP1505635A2 EP1505635A2 (en) | 2005-02-09 |
EP1505635A3 EP1505635A3 (en) | 2007-03-21 |
EP1505635B1 true EP1505635B1 (en) | 2011-01-12 |
Family
ID=9904092
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP04026520A Expired - Lifetime EP1505635B1 (en) | 2000-11-29 | 2001-11-29 | Mass spectrometers and methods of mass spectrometry |
EP20100183535 Withdrawn EP2302661A1 (en) | 2000-11-29 | 2001-11-29 | Mass spectrometer comprising an ion tunnel ion guide, method of mass spectrometry |
Family Applications After (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP20100183535 Withdrawn EP2302661A1 (en) | 2000-11-29 | 2001-11-29 | Mass spectrometer comprising an ion tunnel ion guide, method of mass spectrometry |
Country Status (4)
Country | Link |
---|---|
EP (2) | EP1505635B1 (en) |
AT (2) | ATE480865T1 (en) |
DE (2) | DE60143015D1 (en) |
GB (2) | GB0029088D0 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2302661A1 (en) * | 2000-11-29 | 2011-03-30 | Micromass UK Limited | Mass spectrometer comprising an ion tunnel ion guide, method of mass spectrometry |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8581177B2 (en) | 2011-04-11 | 2013-11-12 | Thermo Finnigan Llc | High duty cycle ion storage/ion mobility separation mass spectrometer |
GB201122178D0 (en) | 2011-12-22 | 2012-02-01 | Thermo Fisher Scient Bremen | Method of tandem mass spectrometry |
GB2497948A (en) | 2011-12-22 | 2013-07-03 | Thermo Fisher Scient Bremen | Collision cell for tandem mass spectrometry |
EP2828880B1 (en) * | 2012-03-23 | 2021-04-28 | Micromass UK Limited | Ion guide construction method |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE19523859C2 (en) * | 1995-06-30 | 2000-04-27 | Bruker Daltonik Gmbh | Device for reflecting charged particles |
DE19628179C2 (en) * | 1996-07-12 | 1998-04-23 | Bruker Franzen Analytik Gmbh | Device and method for injecting ions into an ion trap |
GB0028586D0 (en) * | 2000-11-23 | 2001-01-10 | Univ Warwick | An ion focussing and conveying device |
EP1215712B1 (en) * | 2000-11-29 | 2010-09-08 | Micromass UK Limited | Mass spectrometer and methods of mass spectrometry |
GB0029088D0 (en) * | 2000-11-29 | 2001-01-10 | Micromass Ltd | Ion tunnel |
US7067802B1 (en) * | 2005-02-11 | 2006-06-27 | Thermo Finnigan Llc | Generation of combination of RF and axial DC electric fields in an RF-only multipole |
-
2000
- 2000-11-29 GB GBGB0029088.2A patent/GB0029088D0/en not_active Ceased
-
2001
- 2001-04-20 GB GBGB0109760.9A patent/GB0109760D0/en not_active Ceased
- 2001-11-29 DE DE60143015T patent/DE60143015D1/en not_active Expired - Lifetime
- 2001-11-29 AT AT01310026T patent/ATE480865T1/en not_active IP Right Cessation
- 2001-11-29 EP EP04026520A patent/EP1505635B1/en not_active Expired - Lifetime
- 2001-11-29 AT AT04026520T patent/ATE495542T1/en not_active IP Right Cessation
- 2001-11-29 DE DE60143861T patent/DE60143861D1/en not_active Expired - Lifetime
- 2001-11-29 EP EP20100183535 patent/EP2302661A1/en not_active Withdrawn
Non-Patent Citations (2)
Title |
---|
GERLICH D.: "State-Selected and State-to-State Ion-Molecule Reaction Dynamics. Part 1: Experiment", INTERNET CITATION, XP002339690, Retrieved from the Internet <URL:www.tu-chemnitz.de/physik/ion/publications/ger92.pdf> * |
SHAFFER S.A. ET AL: "AN ION FUNNEL INTERFACE FOR IMPROVED ION FOCUSING AND SENSITIVITY USING ELECTROSPRAY IONIZATION MASS SPECTROMETRY", ANALYTICAL CHEMISTRY, AMERICAN CHEMICAL SOCIETY, US LNKD- DOI:10.1021/AC9802170, vol. 70, no. 19, 1 October 1998 (1998-10-01), pages 4111 - 4119, XP000790313, ISSN: 0003-2700 * |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2302661A1 (en) * | 2000-11-29 | 2011-03-30 | Micromass UK Limited | Mass spectrometer comprising an ion tunnel ion guide, method of mass spectrometry |
Also Published As
Publication number | Publication date |
---|---|
EP1505635A2 (en) | 2005-02-09 |
GB0109760D0 (en) | 2001-06-13 |
ATE480865T1 (en) | 2010-09-15 |
DE60143861D1 (en) | 2011-02-24 |
DE60143015D1 (en) | 2010-10-21 |
EP1505635A3 (en) | 2007-03-21 |
EP2302661A1 (en) | 2011-03-30 |
GB0029088D0 (en) | 2001-01-10 |
ATE495542T1 (en) | 2011-01-15 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP1215712B1 (en) | Mass spectrometer and methods of mass spectrometry | |
EP2436026B1 (en) | Ion tunnel ion guide | |
US6642514B2 (en) | Mass spectrometers and methods of mass spectrometry | |
US6403952B2 (en) | Ion transfer from multipole ion guides into multipole ion guides and ion traps | |
US6977371B2 (en) | Mass spectrometer | |
US9865442B2 (en) | Curved ion guide with non mass to charge ratio dependent confinement | |
US20020063210A1 (en) | Mass spectrometers and methods of mass spectrometry | |
EP2756520B1 (en) | Performance improvements for rf-only quadrupole mass filters and linear quadrupole ion traps with axial ejection | |
EP1505635B1 (en) | Mass spectrometers and methods of mass spectrometry | |
GB2397690A (en) | AC tunnelion guide for a mass spectrometer | |
EP1220291B1 (en) | Mass spectrometer and method of mass spectrometry | |
GB2402807A (en) | Mass spectrometer | |
GB2480160A (en) | Ion guides comprising axial groupings of radially segmented electrodes |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
AC | Divisional application: reference to earlier application |
Ref document number: 1215712 Country of ref document: EP Kind code of ref document: P |
|
AK | Designated contracting states |
Kind code of ref document: A2 Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR |
|
AX | Request for extension of the european patent |
Extension state: AL LT LV MK |
|
RIN1 | Information on inventor provided before grant (corrected) |
Inventor name: GILES, KEVIN Inventor name: BATEMAN, ROBERT HAROLD |
|
PUAL | Search report despatched |
Free format text: ORIGINAL CODE: 0009013 |
|
AK | Designated contracting states |
Kind code of ref document: A3 Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR |
|
AX | Request for extension of the european patent |
Extension state: AL LT LV MK |
|
17P | Request for examination filed |
Effective date: 20070419 |
|
AKX | Designation fees paid |
Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR |
|
17Q | First examination report despatched |
Effective date: 20080312 |
|
RIC1 | Information provided on ipc code assigned before grant |
Ipc: H01J 49/06 20060101AFI20100414BHEP |
|
GRAP | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOSNIGR1 |
|
GRAS | Grant fee paid |
Free format text: ORIGINAL CODE: EPIDOSNIGR3 |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
AC | Divisional application: reference to earlier application |
Ref document number: 1215712 Country of ref document: EP Kind code of ref document: P |
|
AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR |
|
REG | Reference to a national code |
Ref country code: GB Ref legal event code: FG4D |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: EP |
|
REG | Reference to a national code |
Ref country code: IE Ref legal event code: FG4D |
|
REF | Corresponds to: |
Ref document number: 60143861 Country of ref document: DE Date of ref document: 20110224 Kind code of ref document: P |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R096 Ref document number: 60143861 Country of ref document: DE Effective date: 20110224 |
|
REG | Reference to a national code |
Ref country code: NL Ref legal event code: VDEP Effective date: 20110112 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: ES Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20110423 Ref country code: SE Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20110112 Ref country code: PT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20110512 Ref country code: GR Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20110413 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: CY Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20110112 Ref country code: NL Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20110112 Ref country code: FI Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20110112 Ref country code: BE Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20110112 Ref country code: AT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20110112 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: DK Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20110112 |
|
PLBE | No opposition filed within time limit |
Free format text: ORIGINAL CODE: 0009261 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT |
|
26N | No opposition filed |
Effective date: 20111013 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: IT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20110112 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: FR Payment date: 20111128 Year of fee payment: 11 |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R097 Ref document number: 60143861 Country of ref document: DE Effective date: 20111013 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: MC Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20111130 |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: PL |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: CH Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20111130 Ref country code: LI Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20111130 |
|
REG | Reference to a national code |
Ref country code: IE Ref legal event code: MM4A |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: IE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20111129 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: LU Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20111129 |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: ST Effective date: 20130731 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: TR Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20110112 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: FR Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20121130 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: DE Payment date: 20191021 Year of fee payment: 19 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: GB Payment date: 20201021 Year of fee payment: 20 |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R082 Ref document number: 60143861 Country of ref document: DE |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R119 Ref document number: 60143861 Country of ref document: DE |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: DE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20210601 |
|
REG | Reference to a national code |
Ref country code: GB Ref legal event code: PE20 Expiry date: 20211128 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: GB Free format text: LAPSE BECAUSE OF EXPIRATION OF PROTECTION Effective date: 20211128 |