DE10324839B4 - mass spectrometry - Google Patents

Abstract

mass spectrometry with an ion guide (1a, 1b, 1c), wherein the ion guide (1a, 1b, 1c) a stack of a plurality of parallel plate electrodes (2), wherein the plate electrodes (2) are formed are that curved or otherwise non-linear channels in each plate electrode (2) provided for ion guide and the plate electrodes (2) are parallel to the plane of ion motion are arranged, and the ion guide (1a, 1b, 1c) at least one input for receiving ions along a first axis and at least one output from which ions from the ion guide (1a, 1b, 1c) emerge along a second axis.

Description

The The present invention relates to a mass spectrometer having a ion guide and a method of operating such a mass spectrometer.

Multipole rod-set RF ion guides are known and are used to transport ions at relatively low pressures (eg, <10 ^-4 mbar) where ion collisions with background gas molecules are unlikely, and also to transport ions at medium pressures (e.g., 10 ^-4 - 10 mbar) at which ion-molecule collisions can be expected. Multipole rod set RF ion guides are used at medium pressures for a wide range of applications. Multipole rod set RF ion guides are used, for example, as collision cells in which ion-molecule collisions are intended to cause ion fragmentation, and as reaction cells in which ion-molecule collisions are intended to produce ion-molecule reactions. used. Multipole rod-set RF ion guides are also used as cooling devices in which ion-molecule collisions result in compensation for ion and gas molecule temperatures or their kinetic energies. Known multipole rod set RF ion guides have a straight central axis with a single ion input and a single ion output.

A mass spectrometer with a device for focusing and guiding the ions is known from WO 02/43105 A1. This device consists of parallel plate electrodes, which are arranged perpendicular to the ion movement. The ion movement takes place through apertures or recesses in the plate electrodes. To realize complex, in particular curvilinear ion paths, the apertures in the plate electrodes and / or the positions of the individual plate electrodes must be changed in such a device. This is associated with increased effort. Similar devices for ion guide are from the publications GB 2 341 270 A and US 5,206,506 A known.

The DE 196 29 134 C1 discloses a device for transferring ions generated in ion sources into a mass spectrometer, provided with rotatable curved multipole ion guides. The use of plate electrodes is not addressed here.

It is desired a mass spectrometer with an improved and easier to manufacture RF ion guide, especially for curvilinear ion pathways.

These The object is achieved by a mass spectrometer according to claim 1. advantageous Methods for operating such a mass spectrometer are in the claims 45 to 73 indicated.

According to one Aspect of the present invention is a mass spectrometer with an ion guide provided. The ion guide has a plurality of plate electrodes and an input for receiving of ions along a first axis and an exit from the Ions from the ion guide emerge along a second axis, on. The second axis is stationary at an angle θ to first axis, where θ> 0 °. Between the entrance opening and the exit opening the ion guide is an ion guide region provided. According to the preferred embodiment is the angle θ is preferably <10 °, 10-20 °, 20-30 °, 30-40 °, 40-50 °, 50-60 °, 60-70 °, 70-80 °, 80-90 °, 90 ° 100 °, 100-110 °, 110-120 °, 120-130 °, 130-140 °, 140-150 °, 150-160 °, 160-170 ° or 170-180 °. It will also considered angles> 180 °, the ion guide a spiral Ion guide region having. An angle of 0 ° corresponds a condition in which the second axis is parallel to the first axis is. An angle of 180 ° corresponds an embodiment, at a U-shaped ion guide region within the ion guide was provided so that in the ion guide Incoming ions deflected by 180 ° before going in the opposite direction to which the Ions into the ion guide have occurred from the ion guide escape.

In another aspect, the present invention provides a mass spectrometer comprising an ion guide having a plurality of plate electrodes, an input for receiving ions along a first axis, and an exit from which ions exit along a second axis. The ion guide further has a curved ion guide region between the input and the output. The curved ion guide region preferably has a single contiguous, preferably smoothly contiguous ion guide region, through which ions are conducted from the entrance to the exit. In the preferred embodiment, the ion guide region is substantially "S" shaped and / or has a single diffraction point. According to this particular embodiment, the term "curved ion guide region" should not be construed as a labyrinthine ion guide region or a labyrinthine ion guide region having one or more dead ends. The first axis can extend substantially parallel to the second axis and preferably laterally offset from this.

In In another aspect, the present invention provides a mass spectrometer ago, that an ion guide with several plate electrodes, one input for receiving Ions along a first axis, a curved ion guide region and an exit from which ions exit. At this ion guide the second axis is coaxial with the first axis.

A ion guide with a curved Ion guide region and a coaxial first and second axis provides a longer ion guide area, without it would be required that the Distance between the ion guide input and the ion guide output is enlarged. This is particularly advantageous when the ion guide is used as a collision, Fragmentation or reaction cell is used because the increased path length through the gas causes that the Increased probability is that collisions, Fragmentations or reactions occur. According to the preferred embodiment Removes the ion guide an on direction in the manner of a baffle, a plate or a Electrode on, at least partially outside the ion guide region is arranged to block neutral particles or photons, the directly from the entrance of the ion guide to their exit.

According to one In another aspect, the present invention provides a mass spectrometer ago, that a first ion guide with several plate electrodes, one input for receiving Ions and an exit from which ions emerge. The Mass spectrometer also has a second ion guide a plurality of plate electrodes, an input for receiving ions and an exit from which ions exit.

According to the preferred embodiment the mass spectrometer further includes a third ion guide a plurality of plate electrodes, an input for receiving ions and an exit from which ions exit. The mass spectrometer can also do a fourth ion guide with several plate electrodes, one input for receiving Ions and an exit from which ions emerge. According to others embodiments can five, six, seven, eight, nine, ten or more than ten ion guides be provided.

In an operating mode the first ion guide and the second ion guide when used on different DC potentials be held so that out the first ion guide emerging Ions into the second ion guide packed become. The second and the third ion guide may be in use different DC potentials are kept, so that from the second ion guide leaking ions are forced into the third ion guide. The third and the fourth ion guide can also when used on different DC potentials be held so that out the third ion guide leaking ions are forced into the fourth ion guide. It will too embodiments in which ions from the first to the second ion guide and / or from the second to the third ion guide and / or from the third in the fourth ion guide and / or from the fourth ion guide packed become.

In another or further operating mode, the second ion guide on a DC potential different from that of the first ion guide be held so that ions in the first ion guide be captured. The third ion guide can be on one of the one the second ion guide be held different DC potential, so that ions in the second ion guide be captured. The fourth ion guide can be on one of the one the third ion guide different DC potential are held so that ions trapped in the third ion guide become. There are also embodiments in which, for example, ions in the first, the second and the third ion guide or captured in the second and third ion guides.

It is also to be understood that the discussed above Embodiments, the urge of ions from an ion guide as discussed above embodiments can be combined which concern the trapping of ions within an ion guide.

According to one preferred embodiment can be either the first and / or the second and / or the third and / or the fourth ion guide Have ion storage areas. In a first operating mode these can Ion storage areas receive ions through a single opening, and in one second operating mode is enabled that ions through the same opening emerge from the ion storage area.

In In another aspect, the present invention provides a mass spectrometer ago, that an ion guide with multiple plate electrodes, two or more inputs to the Receiving ions and one or more outputs from which ions exit, having.

According to one preferred embodiment has the ion guide preferably two entrances for receiving ions and an exit from which ions emerge, on. According to one another embodiment has the ion guide three entrances for receiving ions and an exit from which ions emerge, on. The plate electrodes can have any shape such that ion beams under any one Angle or from any direction received by the ion guide can be or at any angle or in any direction from the ion guide can escape.

It become further embodiments where 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more than 10 are considered ion inputs 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more than 10 ion outputs are. For example, the ion guide three inputs and three outputs exhibit.

Preferably the mass spectrometer further has at least two equal or different ion sources. The ion sources are preferably at least one of an electrospray ion source ("ESI ion source"), a chemical Atmosphärendruckionisations ion source ("APCI ion source"), an atmospheric pressure photoionization ion source ("APPI ion source"), a matrix-assisted laser desorption ionization ion source ("MALDI ion source"), a laser desorption ionization ion source ("LDI ion source"), an inductive one coupled plasma ion source ("ICP ion source"), an electron impact ion source ("EI ion source"), a chemical ion Ionization ion source ("CI ion source"), an ion source with fast atom bombardment ("FAB ion source") and a liquid secondary ion mass spectrometry ion source ( "LSIMS") ion source.

It become embodiments in which, for example, two ion sources are provided. An ion source may be a continuous ion source in the art an APCI or electrospray ion source, and the other ion source may be a pulsed ion source, such as a MALDI ion source.

It also become embodiments in which more than two ion sources are provided. According to one embodiment can for example at least 3, 4, 5, 6, 7, 8, 9 or 10 APCI ion sources, Electrospray ion sources or any of the other ion sources mentioned above. The preferred ion guide can make it possible that ions from one or more selected ion sources taken as a sample and then mass analyzed.

In In another aspect, the present invention provides a mass spectrometer ago, that an ion guide with several plate electrodes, one or more inputs to the Receiving ions and two or more outputs from which ions emerge, having.

According to the preferred embodiment has the ion guide an input for receiving ions and two outputs, off which ions emerge on. According to one another embodiment becomes the ion beam entering an entrance of the ion guide divided into three or more beams, the third beam via a third exit from the ion guide exit. According to one another preferred embodiment has the ion guide two entrances for receiving ions and two outlets from which ions emerge, on. The mass spectrometer may further comprise at least two ion sources exhibit. An ion beam entering an entrance of the ion guide can be divided into two or more beams, with a first Beam over a first exit from the ion guide emerges and a second Beam over one second exit exits. Preferably, those are in an entrance the ion guide entering ions through one or more electrodes next to arranged at the entrance, one or more electrodes inside the ion guide are arranged, or one or more electrodes next to an output the ion guide are arranged, divided into two or more beams.

One in the ion guide entering ion beam can in a desired ratio in two or more beams are split. Preferably, at least a ray on a percentage of ions entering the ion guide, the 0-10 %, 10 - 20 %, 20 - 30 %, 30 - 40 %, 40 - 50 %, 50 - 60 %, 60 - 70%, 70-80 %, 80 - 90 % or greater than 90% is.

In the preferred embodiment, at least a portion of an ion beam entering the ion guide is switchable to or between one of a plurality of outputs. At least one electrode may be placed adjacent one or more of the outputs to either cause ions to exit the ion guide via this exit, or to substantially prevent ions from exiting the ion guide via that exit. One or more electrodes may be provided adjacent to the entrance or within the ion guide. In one embodiment, an ion beam may be switched between outputs by applying a blocking DC potential to an electrode adjacent an exit of the ion guide and then removing it.

The Mass spectrometer may further include a first ion detector, which is arranged is to receive ions emerging from a first exit, and a second ion detector arranged to be one of second ion output to receive exiting ions have. The mass spectrometer may further include a first mass analyzer, which is arranged to exit from the first exit ions to receive, and a second mass analyzer, which arranged is to receive ions emerging from the second ion exit, exhibit.

The Mass spectrometer may include one or more mass analyzers are arranged to over at least one first exit from the ion guide leaking ions receive, and one or more ion detectors arranged are about to over at least one second ion exit emerging from the ion guide To receive ions.

According to one another embodiment For example, the mass spectrometer includes a first and / or a second ion storage device each having a plurality of plate electrodes. In a first In operation mode, an ion beam enters an ion storage device via an opening and, in a second mode of operation, an ion beam exits through the same aperture of the ion storage device.

It also becomes an embodiment considered, in which the ion guide two outputs wherein an ion storage device is downstream of a Output is arranged and a mass analyzer downstream of the other output is arranged.

In In another aspect, the present invention provides a mass spectrometer with an ion guide before, the multiple plate electrodes, one or more inputs to the Receiving ions and one or more outlets from which ions emerge, having. In a first mode of operation, an ion beam passes over one first opening in the ion guide one and over a second opening from the ion guide out, and in a second mode of operation, an ion beam passes over the second opening into the ion guide.

According to the preferred embodiment In the second mode of operation, an ion beam exits via the first opening the ion guide out. Alternatively, the ion beam in a second mode of operation via a from the first and the second opening different third opening from the ion guide escape.

In In another aspect, the present invention provides a mass spectrometer with an ion storage device comprising a plurality of plate electrodes wherein, in a first mode of operation, an ion beam passes through an aperture in the ion storage device enters and in a second mode of operation an ion beam over the same opening exits the ion storage device.

It become other embodiments in which the ion storage device has two openings has, namely a first opening for receiving ions and a second opening, from which ions the ion storage device leave.

In In another aspect, the present invention provides a mass spectrometer with an ion guide before, the multiple plate electrodes, an input for receiving of ions and an exit from which ions exit. The entrance has a first cross-sectional profile and a first cross-sectional area, and the outlet has a second cross-sectional profile and a second cross-sectional area. The first cross-sectional profile is of the second cross-sectional profile different, and / or the first cross-sectional area is different from the second cross-sectional area.

The first and / or the second cross-sectional profile may be substantially circular, oval, rectangular or square. An ion beam received from the ion guide has a third cross-sectional profile and a third cross-sectional area. Preferably, the first cross-sectional profile and / or the first cross-sectional area are substantially equal to the third cross-sectional profile and / or the third cross-sectional area. The mass spectrometer may further include an ion optical device having a fourth cross-sectional profile and a fourth cross-sectional area downstream of the ion guide. The second cross-sectional profile and / or the second cross-sectional area may be substantially the same as the fourth cross-sectional profile and / or the fourth cross-sectional area. The ion optical device may include an ion guide or a quadrupole mass filter / analyzer having substantially circular cross-sectional profiles. The ion guide may comprise a quadrupole, hexapole, octopole rod set or higher order rod set, a multi-electrode ion tunnel having openings of substantially the same size, or an ion funnel having a plurality of electrodes having progressively smaller openings. The ion optical device may include a lateral acceleration time-of-flight mass analyzer or a magnetic sector analyzer having substantially square or rectangular cross-sectional profiles.

According to others embodiments For example, the ion optical device may include a Fourier transform ion cyclotron resonance mass analyzer ("FTICR mass analyzer") having a substantially circular cross-sectional profile, a two-dimensional (linear) quadrupole ion trap with an im essential circular Cross-sectional profile or a three-dimensional (Paul) quadrupole ion trap with a substantially circular Have cross-sectional profile.

above the "cross-sectional area" and the "cross-sectional profile" were mentioned. Although these are the physical cross-sectional area and the profile of a device or an ion beam, the terms should also as the practical acceptance range or profile of the device or the ion beam analogous to the numerical aperture of an optical Including device be understood.

According to one preferred embodiment indicates the ion guide area between at least one of the inputs and the outputs of ion guide a length on that are in size and / or the shape changes. The ion guide area can also be a length, a width or a height which are increasing in size decreases or whose shape is constantly changing.

Preferably has the ion guide further a second input for receiving ions and / or a second exit, over the ions from the ion guide emerge, with the second input a fifth cross-sectional profile and a fifth Cross sectional area and the second output has a sixth cross-sectional profile and a sixth cross-sectional area having the fifth Cross-sectional profile different from the sixth cross-sectional profile is and / or the fifth Cross sectional area from the sixth cross-sectional area is different.

Preferably are the first cross-sectional profile and the first cross-sectional area and / or the second cross-sectional profile and the second cross-sectional area and / or the fifth Cross-sectional profile and the fifth cross-sectional area and / or the sixth cross-sectional profile and the sixth cross-sectional area are different.

According to the above described embodiments can at least 50%, 60%, 70%, 80%, 90% or 95% of the plate electrodes to be essentially parallel. According to the preferred embodiment are the plate electrodes in a first (for example, horizontal) Plane arranged, and the ion guide is alike curved in the first (eg horizontal) plane. It but also become embodiments in which the plate electrodes are not flat but bent are. In these embodiments can the plates first be arranged in a first (for example, horizontal) plane, however, the plate electrodes then become in a second orthogonal (for example, vertical) plane bent. According to this embodiment can the plate electrodes therefore act rather like a periscope and Transfer ions from one (vertical) plane to another.

The Plate electrodes are preferably substantially the same intervals arranged from each other. According to less preferred embodiments However, the distance between the electrodes may be along the Change the ion guide. For example the distance between the electrodes can increasingly decrease (increase), so that ions funnel-shaped from a relatively large (small) entrance opening to a relatively small (huge) output port promoted become. There will be other embodiments considered, in which the distance between the electrodes along the ion guide changes nonlinearly.

The plurality of plate electrodes preferably include 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, or more than 20 plate electrodes. The plate electrodes of the preferred ion guide may have a thickness of less than or equal to 5 mm, less than or equal to 4.5 mm, less than or equal to 4 mm, less than or equal to 3.5 mm, less than or equal to 3 mm, less than or equal to 2.5 mm less than or equal to 2 mm, less than or equal to 1.5 mm, less than or equal to 1 mm, less than or equal to 0.8 mm, less than or equal to 0.6 mm, less than or equal to 0.4 mm, less than or equal to 0, 2 mm, less than or equal to 0.1 mm or less than or equal to 0.25 mm exhibit.

According to one embodiment can the plate electrodes by applying a conductive paint or of another substance are formed on a substrate. In these embodiments is the typical thickness of the applied conductive layer (electrode layer) in about 250 microns (0, 25 mm).

The Plate electrodes of the preferred ion guide can be spaced a smaller distance or equal to 5 mm, less than or equal to 4.5 mm, less than or equal to 4 mm, less than or equal to 3.5 mm, less than or equal to 3 mm, smaller or equal to 2.5 mm, less than or equal to 2 mm, less than or equal to 1.5 mm, less than or equal to 1 mm, less than or equal to 0.8 mm, smaller or equal to 0.6 mm, less than or equal to 0.4 mm, less than or equal to 0.2 mm, less than or equal to 0.1 mm or less than or equal to 0.25 mm apart.

According to the preferred embodiment AC or RF voltage is applied to the plate electrodes. neighboring Plate electrodes can opposite phases of the AC or RF voltage can be supplied. The change or HF voltage preferably has a frequency of <100 kHz, 100-200 kHz, 200-300 kHz, 300 - 400 kHz, 400 - 500 kHz, 0.5 - 1.0 MHz, 1.0 - 1.5 MHz, 1.5 - 2.0 MHz, 2.0 - 2.5 MHz, 2.5 - 3.0 MHz, 3.0 - 3.5 MHz, 3.5 - 4.0 MHz, 4.0 - 4.5 MHz, 4.5 - 5.0 MHz, 5.0 - 5.5 MHz, 5.5 - 6.0 MHz, 6.0 - 6.5 MHz, 6.5 - 7.0 MHz, 7.0 - 7.5 MHz, 7.5 - 8.0 MHz, 8.0 - 8.5 MHz, 8.5 - 9.0 MHz, 9.0 - 9.5 MHz, 9.5-10.0 MHz or> 10.0 MHz.

The AC or RF voltage is preferably <50 V from tip to tip, 50 - 100 V from tip to tip, 100 - 150 V from tip to tip, 150-200 V from tip to tip, 200 - 250 V from tip to tip, 250 - 300 V from tip to tip, 300 - 350 V from tip to tip, 350 - 400 V from tip to tip, 400 - 450 V from tip to tip, 450 - 500 V from tip to tip or> 500 V from tip to tip.

Preferably becomes the ion guide kept in use at a pressure that is from the following Group selected is: (i) greater or equal to 0.0001 mbar, (ii) greater than or equal to equal to 0.0005 mbar, (iii) greater or less equal to 0.001 mbar, (iv) greater or equal to 0.005 mbar, (v) greater or less equal to 0.01 mbar, (vi) greater than or equal to equal to 0.05 mbar, (vii) larger or equal to 0.1 mbar, (viii) greater or equal to 0.5 mbar, (ix) greater than or equal to 1 mbar, (x) larger or equal to 5 mbar and (xi) greater or equal to 10 mbar.

Preferably becomes the ion guide kept in use at a pressure that is from the following Group selected is: (i) less than or equal to 10 mbar, (ii) less than or equal to 5 mbar, (iii) less than or equal to 1 mbar, (iv) less than or equal to 0.5 mbar, (v) less than or equal to 0.1 mbar, (vi) less than or equal to 0.05 mbar, (vii) less than or equal to 0.01 mbar, (viii) smaller or equal to 0.005 mbar, (ix) less than or equal to 0.001 mbar, (x) smaller or equal to 0.0005 mbar and (xi) less than or equal to 0.0001 mbar.

Preferably becomes the ion guide kept in use at a pressure that is from the following Group selected is: (i) between 0.0001 and 10 mbar, (ii) between 0.0001 and 1 mbar, (iii) between 0.0001 and 0.1 mbar, (iv) between 0.0001 and 0.01 mbar, (v) between 0.0001 and 0.001 mbar, (vi) between 0.001 and 10 mbar, (vii) between 0.001 and 1 mbar, (viii) between 0.001 and 0.1 mbar, (ix) between 0.001 and 0.01 mbar, (x) between 0.01 and 10 mbar, (xi) between 0.01 and 1 mbar, (xii) between 0.01 and 0.1 mbar, (xiii) between 0.1 and 10 mbar, (xiv) between 0.1 and 1 mbar and (xv) between 1 and 10 mbar.

Preferably, in use, the ion guide is maintained at a pressure selected from the group consisting of: (i) greater than or equal to 1 × 10 ^-7 mbar, (ii) greater than or equal to 5 × 10 ^-7 mbar, (iii) greater or equal to 1 × 10 ^-6 mbar, (iv) greater than or equal to 5 × 10 ^-6 mbar, (v) greater than or equal to 1 × 10 ^-5 mbar and (vi) greater than or equal to 5 × 10 ^-5 mbar.

Preferably, in use, the ion guide is maintained at a pressure selected from the following group: (i) less than or equal to 1 × 10 ^-4 mbar, (ii) less than or equal to 5 × 10 ^-5 mbar, (iii) smaller or equal to 1 × 10 ^-5 mbar, (iv) less than or equal to 5 × 10 ^-6 mbar, (v) less than or equal to 1 × 10 ^-6 mbar, (vi) less than or equal to 5 × 10 ^-7 mbar and (vii ) is less than or equal to 1 × 10 ^-7 mbar.

Preferably, in use, the ion guide is maintained at a pressure selected from the following group: (i) between 1 x 10 ^-7 and 1 x 10 ^-4 mbar, (ii) between 1 x 10 ^-7 and 5 x 10 ^-5 mbar, (iii) is between 1 x 10 ^-7 and 1 x 10 ^-5 mbar, (iv) between 1 × 10 ^-7 and 5 × 10 ^-6 mbar, (v) between 1 × 10 ^-7 to 1 × 10 ^-6 mbar, (vi) between 1 × 10 ^-7 and 5 × 10 ^-7 mbar, (vii) between 5 × 10 ^-7 and 1 × 10 ^-4 mbar, (viii) between 5 × 10 ^-7 and 5 × 10 ^-5 mbar, (ix) between 5 × 10 ^-7 and 1 × 10 ^-5 mbar, (×) between 5 × 10 ^-7 and 5 × 10 ^-6 mbar, (xi) between 5 × 10 ^-7 and 1 × 10 ^-6 mbar, (xii) between 1 × 10 ^-6 and 1 × 10 ^-4 mbar, (xiii) between 1 × 10 ^-6 and 5 x 10 ^-5 mbar, (xiv) between 1 x 10 ^-6 and 1 x 10 ^-5 mbar, (xv) between 1 x 10 ^-6 and 5 x 10 ^-6 mbar, (xvi) between 5 x 10 ^-6 and 1 x 10 ^-4 mbar, (xvii) is between 5 × 10 ^-6 and 5 × 10 ^-5 mbar, (xviii) is between 5 × 10 ^-6 and 1 × 10 ^-5 mbar, (xix) is between 1 x 10 ^{- 5} and 1 × 10 ^-4 mbar, (xx) between 1 × 10 ^-5 and 5 × 10 ^-5 mbar and (xxi) between 5 × 10 ^-5 and 1 × 10 ^-4 mbar.

The ion guide preferably further comprises a first outer (for example top / top) plate electrode and one on a second side the ion guide arranged second (for example, lowest / lower) outer plate electrode on. According to less preferred embodiments no upper or lower plate electrode can be provided. In these embodiments may be due to AC or RF confinement caused by other means, how an adjacent set of rod assemblies is provided prevents be that ions emerge from the upper part or the lower part of the ion guide.

According to one another embodiment can from the center of the ion guide distant plate electrodes on constantly increasing positive or negative DC potentials be held so that ions, increasingly moving away from the central region of the ion guide to the middle of the ion guide be pushed back. According to this embodiment can no external plate electrodes be provided, which include the ion guide.

It can do that be taken care of that first outer plate electrode and / or the second outer plate electrode to a DC bias with respect to the mean voltage of Plate electrodes to which an AC or RF voltage is applied to be biased.

These Bias voltage is preferably less than -10 V, -9 to -8 V, -8 to -7 V, -7 to -6 V, -6 to -5 V, -5 to -4 V, -4 to -3 V , -3 to -2 V, -2 to -1 V, -1 to 0 V, 0 to 1 V, 1 to 2V, 2 to 3V, 3 to 4V, 4 to 5V, 5 to 6V, 6 to 7V, 7 to 8V, 8 to 9V, 9 to 10V or more than 10V.

According to one embodiment is the upper and / or lower plate, so the outer electrodes, fed a pure DC voltage (i.e., there is no change or HF voltage applied). According to one another embodiment the upper and / or the lower plate is a pure change or RF voltage supplied (i.e., the plates are not referenced with a DC voltage biased to the other plate electrodes). According to one another embodiment For example, the upper and / or lower plate becomes both a DC voltage as well as an AC or RF voltage (i.e., the outer electrodes are in relation to the other electrodes by a DC voltage biased, and they will also have an AC or RF voltage fed).

According to the above described embodiments can the ion guide further comprise an opening disposed in the upper and / or the lower plate. The opening can be used to enable that ions and / or a gas and / or a laser beam enter the ion guide and / or emerge from this.

According to one embodiment become one or more of the plate electrodes in use one different from that of the other plate electrodes Held DC potential, so that within the ion guide more discrete ion guide areas are formed. For example, you can one or more of the plate electrodes to the center of the stack of Plate electrodes held at a DC potential so they form a potential wall. According to one such arrangement can then two parallel and longitudinally extending ion guide regions within the ion guide are formed, for example, an upper ion guide region and a lower ion guide area is formed. According to others embodiments can formed more than two parallel ion guide regions become.

According to one another embodiment become multiple plate electrodes at significantly different DC potentials held. According to these embodiments can maintain a DC potential profile between the plates become. For example, between the plate electrodes, a V-shaped DC potential profile be maintained so that ions to the central region of the ion guide pushed become. According to this embodiment need upper and lower plate electrodes, which make the ion guide effective lock in, possibly are not provided, so that the ion guide of Upper part and appear from the lower part substantially open can.

Preferably, the ion guide has a first outer portion, a second outer Ab and an intermediate portion between the first and second outer portions, wherein the DC potential at which the plate electrodes are held is increased in the first and / or second outer portions with respect to the intermediate portion so that ions become a central region of the ion guide be returned.

It become further embodiments contemplated in which the applied to the plate electrodes DC voltage potentials can change over time. Preferably are on the plate electrodes have one or more transient DC potentials or one or more DC potential waveforms applied. This may preferably cause ions from a region (e.g. an upper portion) of the ion guide to another area (for example, a lower area) the ion guide packed become.

According to another embodiment, which is not part of the present application, a mass spectrometer with an ion guide is provided, wherein the ion guide comprises:
several electrode layers and
multiple insulator layers interspersed or interleaved between the electrode layers.

Preferably are at least 10%, 20%, 30%, 40%, 50 60%, 70%, 80%, 90 % or 95% of the electrode layers are arranged on the insulator layers or deposited on it.

According to another embodiment, which is not part of the present application, a mass spectrometer with an AC or RF ion guide is provided, wherein the ion guide comprises:
several electrodes and
a plurality of insulators interspersed between the electrodes, inserted or interleaved,
wherein the electrodes are mounted on or deposited on the insulators.

Preferably has the ion guide an ion input and an ion output, wherein substantially prevents gas molecules within the ion guide elsewhere than through the ion input or the ion output from the ion guide escape. It can be a gas opening be provided for introducing gas into the ion guide, however, it may be preferable to substantially prevent gas from passing therethrough gas opening from the ion guide exit.

In another embodiment not belonging to the present application is a mass spectrometer with a first ion guide, a Gaskollisions- / reaction cell and a second ion guide. The second ion guide has a plurality of plate electrodes, an input for receiving ions, an ion guide region, through the ion guide runs, and an exit from which ions exit. There are preferably no direct line of sight from the entrance to the exit of the second ion guide.

According to the preferred embodiment comprises the mass spectrometer further an electrospray ion source ("ESI ion source"), a chemical Atmospheric pressure ionization ion source ("APCI ion source"), an atmospheric pressure photoionization ion source ("APPI ion source"), a matrix-assisted laser desorption ionization ion source ("MALDI ion source"), a laser desorption ionization ion source ("LDI ion source"), an inductive coupled plasma ion source ("ICP ion source"), an electron impact ion source ("EI ion source"), a chemical Ionization ion source ("CI ion source"), an ion source with fast atom bombardment ("FAB ion source") or a liquid secondary ion mass spectrometry ion source ( "LSIMS") ion source.

The Mass spectrometers may also include a mass analyzer located downstream of the second ion guide. The mass analyzer may include a Time of Flight mass analyzer, a quadrupole mass analyzer, a Fourier transform ion cyclotron resonance mass analyzer ("FTICR mass analyzer") is a two-dimensional (linear) quadrupole ion trap, a three-dimensional (Paul) quadrupole ion trap or a magnetic sector mass analyzer exhibit.

ion guides according to the preferred embodiment can advantageously an ion guide region with at least one curved one or nonlinear section, and they may more than have an ion input and / or ion output. It would be very difficult and overly expensive, too try equivalent ion guides from conventional Multipole rod set RF ion guides manufacture and build.

The ion guide according to the preferred embodiment is constructed of a series of shaped plates or plate electrodes. The plates need not be straight, and you can have more than one ion input and / or ion output. The preferred ion guides are relatively easy They are considerably cheaper than conventional ones Multipole rod set ion guides. It can also easy ion guides be made with complicated shapes. For example, several identical ones Plates with complicated shapes easily and inexpensively through Pressure cutting or punching, photochemical etching, laser cutting, wire erosion, Spark erosion, etc. from thin Sections are made of sheet metal. Furthermore, the Plates stacked in an assembly or multiple array with the plates spaced and insulated, and with alternating ones Plates are electrically connected together, so that adjacent Plates out of phase by 180 ° held together.

According to one preferred embodiment is the RF ion guide off constructed of a series of shaped plates arranged in a stack are, with suitable DC potentials to a supreme or upper plate electrode and to a lower or lower flat Plate electrode are applied. This is a very simple one and cost-effective Type of building a complex RF ion guide. The top and the bottom plate can with an AC or RF voltage applied thereto or a combination of AC or DC and DC voltages are operated.

According to the preferred embodiment can the plates are manufactured with an input and an output, which are not aligned so that there is no line of sight through the ion guide gives, so that neutral Particles, big Particles or droplets or radiation, such as visible light or UV light just not through the ion guide pass.

According to a further aspect not belonging to the present application, a method for mass spectrometry is provided which comprises the following steps:
Generating ions from an atmospheric pressure ion source and
Guiding the ions through an ion guide, the ion guide comprising a plurality of plate electrodes, an input for receiving ions, and an exit through which ions exit the ion guide, wherein an ion guide channel is formed in the plate electrodes and extends substantially the length of the ion guide and wherein the plate electrodes are arranged in the plane of ion movement.

According to one Another aspect not belonging to the present application is a method for producing an ion guide for a Mass spectrometer provided in which multiple electrodes with multiple Insulators interspersed or nested to be arranged an ion guide with a plurality of electrodes arranged on the insulators, so that one Ion guide stack is formed.

According to one Another aspect not belonging to the present application is a method for producing an ion guide for a Mass spectrometer provided, in which several electrode layers on a plurality of insulator layers are deposited to an ion guide stack with a plurality of electrode layers arranged on the insulator layers to build.

Of the The term "plate electrode" as used in the present application should be interpreted broadly become. According to one preferred embodiment the plate electrodes are thin Metal sheets on. According to others embodiments can however, the plate electrodes have wire nets or grids and therefore openings to have. The term is also meant to include electrodes that have been applied to a substrate in the manner of an insulator.

According to the invention are the ion guide forming electrodes as opposed to an ion tunnel or ion funnel ion guide the ring electrodes in a plane perpendicular to the ion movement direction are arranged, arranged in the plane of ion movement.

The ion guides described above can either as an ion guide can be used per se, or they can be a fragmentation, Collision, reaction or collision cooling cell form.

Various embodiments The present invention will now be described by way of example only with reference to FIG the attached drawing, in which:

1A a plan view of an AC or RF ion guide according to an embodiment shows and 1B a sectional view of the ion guide 1A along a cross section AA,

2 shows an embodiment in which the plates have a C-shaped ion path, so that the ions are rotated by 90 ° from the input to the output,

3 shows an embodiment in which the plates have an S-shaped ion path, so that ions are laterally offset from the input to the output,

4 Fig. 5 shows an embodiment in which the plates have an Ω-shaped ion path so that there is no line of sight between the input and the output, but the ions are not offset laterally or obliquely as they emerge from the ion guide,

5 shows an embodiment in which an S-shaped ion path is formed of two plate stacks with C-shaped ion paths,

6 1 shows an embodiment in which an Ω-shaped ion path is formed from two plate stacks with S-shaped ion paths,

7 1 shows an embodiment in which an Ω-shaped ion path is formed from two plate stacks with C-shaped ion paths,

8th 1 shows an embodiment in which the ion guide has two inputs and one output,

9 another embodiment in which the ion guide has two inputs and one output,

10 another embodiment in which the ion guide has two inputs and one output,

11 another embodiment in which the ion guide has two inputs and one output,

12 an embodiment in which the ion guide has three inputs and one output,

13 shows an embodiment in which the ion guide has an input and two outputs,

14 an embodiment in which the ion guide has an input and three outputs,

15 shows an embodiment in which the ion guide has two inputs and two outputs,

16A an embodiment in which the ion guide has three openings that can be used selectively as inputs and outputs, and 16B shows the same ion guide used in another mode of operation,

17 shows an embodiment of a three-hole ion guide combined with an RF ion guide having an aperture and an ion capture region,

18A shows an embodiment of an ion guide with three ion paths of different size and shape and

18B shows a cross section of an ion guide with a non-rectangular cross-sectional profile,

19A shows an embodiment in which an ion guide has a total of six openings, and 19B another embodiment in which an ion guide has a total of six openings,

20 shows a mass spectrometer having a preferred ion guide,

21A shows an embodiment of an ion guide operated with a DC voltage applied to the top and bottom plates, 21B shows an embodiment of an ion guide, which is operated with an applied to the top and bottom plate alternating or RF voltage, and 21C shows an embodiment of an ion guide, which is operated with both a DC voltage and with an AC or RF voltage applied to the top and bottom plate, and

22 shows an ion guide consisting of a stack of insulators attached or deposited on electrodes.

It be some different embodiments of the present invention. A common feature the various embodiments is, however, that a AC or RF ion guide is provided, which has a plurality of plate electrodes. The Plate electrodes are preferably relatively thin and may be made of metal sheets. Alternatively you can the plate electrodes from a non-conductive plate, for example made of glass or ceramic, which then at least partially with an electrically conductive coating is coated. The glass or Ceramic plate can be shaped in the same way as the metal plates be an ion guide area provide.

The Glass or ceramic plates are preferably contiguous, and Areas of their surface can with a conductive coating to be molded electrodes to lead to provide the ions.

The preferred plate electrodes differ from conventional ones Rod set electrodes having a circular cross-sectional profile and their length usually much bigger as their width. In contrast, the plate electrodes which guide the ion guide according to the before embodiment form, preferably a rectangular cross-sectional profile, and The width of the electrodes can be compared with the length of the electrodes to be (or even bigger as this).

1A shows a top view of an AC or RF ion guide 1a composed of a stack of plate electrodes such that an S-shaped ion path within the AC or RF ion guide 1a is formed. The AC or RF ion guide 1a preferably consists of a series of identical plates, each about 0.7 mm thick and preferably spaced 1.0 mm apart.

1B is a sectional view along AA of in 1A represented ion guide, and it is an AC or RF ion guide therein 1a shown a stack of six plate electrodes 2 with an upper plate electrode 3 and a lower plate electrode 4 having. The inner opening or ion guide area 5 within the ion guide 1a is preferably 11.2 mm high and 5 mm wide. The length of the through 1A illustrated ion guide 1a extending ionic path can be about 60 mm. The frequency of the RF supply connected to the ion guide 1a forming plates 2 . 3 . 4 can be 6 MHz, and the RF voltage can be 200 V peak to peak. The top or top plate electrode 3 and the bottom or bottom plate electrode 4 may, in one embodiment, be +3 volts versus the average voltage of the shaped plate electrodes 2 to which the AC or RF voltage was applied should be biased.

The preferred AC or RF ion guide 1a preferably has a plurality of plate electrodes arranged in a stack or a field 2 on. The ion guide 1a preferably has an upper plate electrode 3 and a lower plate electrode 4 on. The electrodes 2 not the top plate electrode 3 and the lower plate electrode 4 are preferably a channel provided in the plates substantially along their entire length. At the in 1A Example shown are the plate electrodes 2 and the upper plate electrode 3 and the lower plate electrode 4 S-shaped. The one in each of the plate electrodes 2 provided channel causes that in the ion guide 1a an ion guide region 5 provided.

After the basic arrangement of the ion guide 1a has been described, various embodiments will now be described in more detail.

A first main embodiment of the present invention will now be described with reference to FIGS 2 - 4 described in which various arrangements of an AC or RF ion guide 1a are shown. Curved or otherwise non-linear channels are in the plate electrodes 2 With Exception of the upper plate electrode 3 and the lower plate electrode 4 provided. The ion guide 1a has an entrance 6 and an exit 7 on, and the ion guide area 5 is arranged so that it is between the ion input port 6 and the ion exit port 7 no line of sight exists. This is advantageous in that radiation, neutral particles or droplets at the entrance 6 in the ion guide 1a enter, not obliquely or laterally from the ion guide 1a be offset and therefore in the in the 2 and 3 embodiments not shown by the output 7 from the ion guide 1a escape. At the in 4 illustrated embodiment, a device outside the ion guide region 5 be arranged to receive radiation, neutral particles or droplets coming directly from the entrance 6 to the exit 7 run, block. This device may comprise a baffle, a plate or an electrode.

The ion guide 1a may preferably be operated at average pressures of, for example, between 0.0001 and 10 mbar. Because of the presence of gas, frequent collisions between ions and molecules occur, which can cause ions to slow down and possibly even within the ion guide 1a come to a standstill.

A second main embodiment of the present invention will now be described with reference to FIGS 5 - 7 described. According to the second main embodiment, there are two or more AC or RF ion guides 1a . 1b provided, each ion guide 1a . 1b comprises a stack of plate electrodes. Each plate electrode 2 is shaped to provide a path for the ions to be passed therethrough. A DC potential may be applied to the region where the ions are an ion guide 1a leave and then into an adjacent ion guide 1b enter. The DC potential can create an axial field that helps to ionize in the presence of a gas as it passes through the ion guides 1a . 1b to keep moving.

At the in 7 In the embodiment shown, a potential well can be generated along the ion beam axis. For example, ions can be within the second ion guide 1b or the third ion guide 1c be captured. That in the area between the output of the first ion guide 1a and the entrance of the second ion guide 1b applied potential and that in the region between the output of the second ion guide 1b and the entrance of the third ion guide 1c applied potential can be chosen so that in a first operating mode ions within the second ion guide 1b be captured. Similarly, it could be ensured that ions in the third ion guide 1c be captured. Other embodiments are envisioned where ions within the second ion guide 1b and the third ion guide 1c be captured. Ions can be within a specific ion guide 1a . 1b . 1c be captured by the downstream ion guide 1b . 1c . 1d is held at a different DC potential.

A third main embodiment of the present invention will now be described with reference to FIGS 8th - 12 described. According to the third main embodiment, two or more inputs of the ion guide 1a be provided, which has one or more outputs. Alternatively, the ion guide 1a have one or more inputs and two or more outputs. In contrast, conventional multipole rod set ion guides have only a single ion input and a single ion output.

The 8th - 11 show embodiments in which the ion guide 1a two entrances 6a . 6b and wherein it is possible to receive ions from an input 6a for receiving ions from another input 6b switch. Alternatively, two or more ion beams may be merged. The ion inputs may be at angles in the range 0 - 10 °, 10 - 20 °, 20 - 30 °, 30 - 40 °, 40 - 50 °, 50 - 60 °, 60 - 70 °, 70 - 80 °, 80 - 90 °, 90 ° to 100 °, 100 ° to 110 °, 110 ° to 120 °, 120 ° to 130 °, 130 ° to 140 °, 140 ° to 150 °, 150 ° to 160 °, 160 ° to 170 ° or 170 ° to 180 ° to each other ,

The ion guide 1a may be used with a first ion source (not shown) for analyzing analyte ions and a second ion source (not shown) for generating reference ions. Alternatively, the ion guide may be used with two different types of ion sources and may be used, for example, in conjunction with an atmospheric pressure ionization ion source ("API ion source") and a matrix assisted laser desorption ionization ion source ("MALDI ion source"). The plate electrodes may be made in any shape so that ion beams can be received by the ion guide at any angle or direction, or exit the ion guide at any angle or in any direction.

At the in 8th illustrated embodiment, the plate electrodes of the ion guide are so ge forms that the two inputs are on opposite sides of the disks and the output is on a third side. The plate electrodes may be substantially rectangular or square. 9 shows an embodiment in which the plates are shaped so that the inputs are at right angles to each other so that in use the ion beams received by the inputs are both oblique to the ion beam emanating from the ion guide. Alternatively, the inputs may be on the same side of the disc, with the output on a second side, as in FIG 10 is shown. 11 shows another embodiment in which one of the inputs and the output are on opposite sides of the plate, directly opposite each other, and a second input is on a third side.

12 shows an embodiment in which the AC or RF ion guide 1a three entrances 6a . 6b . 6c having. Other embodiments are contemplated in which four or more inputs may be provided. In the 12 illustrated ion guide 1a can be used to switch between or combine ion beams, for example from two different ion sources to analyze analyte ions, and a third ion beam to generate reference ions.

An AC or RF ion guide 1a with several ion inputs 6a . 6b . 6c can be used to multiplex between different ion sources within a multiple array of ion sources. Such an arrangement allows parallel analysis of a large number of sample streams, for example from four to eight different liquid or gas streams from four to eight different liquid or gas chromatography columns.

A fourth main embodiment of the present invention will now be described with reference to FIGS 13 - 16 described. There are ion guides 1a in the way of in 13 considered that have more than one exit 7a . 7b so that an ion current can be split between two or more outputs or switched between two or more outputs. Such an embodiment can be used, for example, to split or switch ions between two detectors. For example, ions may be split or switched between a Faraday cup detector and an ion counting detector to provide a detection system that has a very wide dynamic range and yet is capable of detecting and counting individual ions.

Alternatively, such an ion guide 1a used to divide or switch ions between a detector and another analyzer in the manner of a mass analyzer. For example, ions may be split so that a portion of the ion signal is monitored on a detector while the remainder is passed to a device for further analysis, such as a collision cell and mass analyzer for ionic structure studies or for more specific ion monitoring.

Alternatively, such an ion guide 1a used to split or switch ions between two mass analyzers. For example, ions can be split between two mass analyzers operating at different resolutions, or between two mass analyzers tuned for different masses.

In the 13 The illustrated embodiment may be used to divide an ion beam into two ion beams to be routed to two or more different mass analyzers, and may provide a means for measuring isotopic ratios. Two mass analyzers can be tuned to the appropriate masses to measure any desired isotope ratio. This embodiment is the inverse of in 8th illustrated embodiment, in which an AC or RF ion guide 1a with two entrances 6a . 6b and a single outlet 7 is provided.

All in the 8th - 12 The illustrated embodiments may be reversed to include a single input and two (or more) outputs.

14 shows an embodiment in which an AC or RF ion guide 1a three outputs 7a . 7b . 7c having. Other embodiments are contemplated in which more than three outputs are provided. In the 14 illustrated embodiment with three outputs 7a . 7b . 7c allows an ion current to be switched or split between various detectors and / or mass analyzers in any combination.

Embodiments are contemplated wherein the AC or RF ion guide 1a has multiple inputs and multiple outputs. In 15 For example, an embodiment is shown in which an ion guide 1a with two entrances 6a . 6b and two outputs 7a . 7b is provided. According to this embodiment, the ion guide 1a Receive ions from two different ion sources, such as a thermionic ion source and an inductively coupled plasma ion source ("ICP ion source"). The ions can then be directed to two different mass analyzers, each tuned to two different isotopic mass-to-charge ratios.

Embodiments are contemplated wherein the AC or RF ion guide 1a can be used with multiple inputs and / or outputs, with ions going one way in one mode of operation and going the other way in another mode of operation. For example, acts in the in the 16A and 16B illustrated embodiment, the in 16A illustrated opening 7 in the 16A illustrated operating mode as an output port, the same opening (now with 6 ' however, as in 16B is shown to act as an input port in a subsequent operating mode. In the subsequent operating mode, ions pass through a third opening 7 ' from the ion guide 1a out.

There are ion guides 1a in which ion currents can be conducted back and forth within an overall array of ion sources, analyzers and detectors. For example, it may be an AC or RF ion guide 1a in an operating mode, allow ions to pass through from an ionization source to a mass analyzer and the ion guide 1a In another mode of operation, it may receive ions from the mass analyzer or an ion trap and direct them through a third orifice to a detector. Ions can be passed through an aperture or prevented from passing through an aperture by applying a suitable potential to an element adjacent a particular aperture. An AC or RF ion guide 1a with multiple openings can be used to direct an ion current in multiple directions.

17 shows a further embodiment with a first AC or RF ion guide 1a with three openings 6 . 7 . 8th and a second AC or RF ion guide 1b with a single opening 9 , Ions pass through the entrance opening 6 into the first AC or RF ion guide 1a and become 90 ° to the opening 8th directed. The ions then run over the opening 9 into the second AC or RF ion guide 1b , The second AC or RF ion guide 1b has a single opening 9 and an ion storage area 10 for receiving and storing ions. In an operating mode, it can be ensured that ions in the trapping or storage area 10 stored or captured over the opening 9 from the second AC or RF ion guide 1b exit and over the opening 8th , through which the ions have previously leaked, back into the first AC or RF ion guide 1a enter. The ions then become 90 ° to the exit opening 7 passed through which the ions from the first ion guide 1a escape.

The ions may be caused to be supported by a certain opening 6 . 7 . 8th . 9 to move by applying appropriate voltages to elements immediately adjacent to the opening, or this may not be the case. For example, ions may be caused to enter the second AC or RF ion guide 1b by entering or leaving the DC voltage potential applied to the second AC or RF ion guide with respect to the first AC or RF ion guide 1a applied DC potential is reduced or increased.

18A shows further embodiments in which an AC or RF ion guide 1a is used to change the cross-sectional beam profile of an ion beam or to change the cross-sectional area of the ion beam. According to one embodiment, the inlet opening 6 preferably both in size and the cross-sectional shape are adapted to the incoming ion beam. Similarly, the outlet openings 7a . 7b in size and cross-sectional profile to match the optimum size and cross-sectional profile of the ion optical devices located downstream of the AC or RF ion guide 1a located and the from the ion guide 1a to receive exiting ionic current. An entrance opening 6 and the two exit openings 7a . 7b can all have different cross-sectional areas and / or cross-sectional profiles. Preferably, the cross-sectional area of the entrance opening (s) is substantially equal to the sum of the cross-sectional areas of the exit openings. The guiding areas between the openings 6 . 7a . 7b may also have lengths whose size and / or shape is constantly changing.

18B shows an embodiment of an AC or RF ion guide 1a in which the plate electrodes 2 which carry the AC or RF voltage, have a channel whose width extends from an upper portion of the ion guide 1a to the lower portion of the ion guide 1a increasingly changing. According to the in 18B In the embodiment shown, the width of the channel in the plate electrodes 2 such that a through the ion guide 1a passing through the ion beam has a substantially circular cross-sectional profile.

Other embodiments are contemplated in which the shape and size of each aperture or ion path may be different from those of the others. Such AC or RF ion guides 1a can also be made with other than rectangular or circular cross-sectional shapes or profiles.

In the 19A and 19B Further embodiments are shown in which it is ensured that ions through the upper plate electrode 3 and / or through the lower plate electrode 4 into the AC or RF ion guide 1a enter and / or exit from this. The in the 19A and 19B illustrated embodiment is similar to those in the 12 . 14 and 15 illustrated embodiments, but with an additional opening 11 in the upper plate electrode 3 is provided and an additional opening 12 in the lower plate electrode 4 is provided. The additional openings 11 . 12 can be used to allow ions (or gas or a laser beam) into the AC or RF ion guide 1a introduced or to allow ions or gas or a laser beam) from the AC or RF ion guide 1a escape. In the in the 19A and 19B Example shown has the AC or RF ion guide 1a a total of six openings.

20 shows a top view of a preferred embodiment, in which an AC or RF ion guide 1a downstream of a collision cell 34 in a mass spectrometer 30 is provided. For ease of illustration, various horizontally extending vacuum ports are shown, while according to the preferred embodiment, the vacuum ports are preferably vertically below the mass spectrometer 30 run. The mass spectrometer 30 preferably has an inductively coupled plasma ion source ("ICP ion source") (not shown). A number of sampling cones 31 and vacuum pumps may be provided to allow a portion of the ions emitted by the ion source to enter a vacuum chamber 32 entry. It is then ensured that the ions in an HF-hexapole ion guide 33 enter, preferably an enclosed section 34 having. Gas is preferably in the enclosed section 34 initiated so that through the enclosed section 34 running ions with the in the enclosed section 34 collide introduced gas. These collisions cause the ions to lose energy. Argon ions and other ions from the plasma can be significantly attenuated, preferably by charge exchange with the collision gas in the ion beam. The remaining analyte ions then emerge from the hexapole ion guide 33 and enter an S-shaped AC or RF ion guide 1a which displaces ions laterally. These ions then emerge from the S-shaped AC or RF ion guide 1a off and run through an intermediate chamber opening 36 into the next vacuum chamber (analyzer vacuum chamber) 35 , The ions then pass through a quadrupole mass filter 37 with a pre-filter 38 and a postfilter 39 for mass analysis and then to a detector 40 which is preferably cylindrical in shape and arranged along the horizontal axis.

ICP ion sources usually generate high levels of fast neutral atoms and molecules and an intense beam of visible and UV radiation. The collision / reaction cell 34 can also lead to a background of faster neutral atoms and molecules. The visible radiation and ultraviolet radiation and the fast particles result in a continuum of background noise, if allowed to pass to the detector. This noise interferes with the measurement of analyte signals and limits their detection. The S-shaped RF ion guide 1a advantageously eliminates any line of sight, thereby preventing fast neutral particles and radiation from blocking the detector 40 while ions are still for subsequent mass analysis and detection by the mass spectrometer 30 be guided.

The ionic signal for uranium ions (m / z 238) was determined using the in 20 measured embodiment. An ICP burner was the source of the ions to be analyzed by an analyzer with a low mass resolution of 12.6 and a high mass resolution of 15.6. The ICP burner was set so that the x-axis was 2.54, the y-axis was -0.69, and the z-axis was 1.10. The pressure in the analyzer was kept 10 ^-5 mbar at 5.1 x, and it was a collision gas of hydrogen and helium in the collision cell 34 available. A cone lens 31 was at a potential of 50V A hexapole output lens was placed at a potential of 190 V, and the hexapole 33 was biased by 0V. The ions were in the quadrupole mass analyzer 37 an energy of 2 eV and were detected by a photomultiplier with a gain of 450. The measurements indicated that the transmittance of ions through the S-shaped AC or RF ion guide 1a between 50% and 100%, while substantially eliminating the transmission of fast neutral particles, visible radiation and UV radiation.

In the 21A - C are shown three different configurations involving an AC or RF ion guide 1a either a DC bias, an AC or RF voltage, or a combination of DC bias and AC or RF voltage applied to the top plate electrode 3 or the lower plate electrode 4 are created, operated. If an AC or RF voltage to the top plate electrode 3 and the lower plate electrode 4 is created, as in the 21B and 21C is shown, the upper plate electrode 3 and the lower plate electrode 4 either directly with the next but one plate electrode 2 be coupled or via a capacitor with another plate electrode 2 be coupled so that between adjacent electrodes 2 . 3 . 4 a 180 ° phase shift is maintained.

The transmission of atomic ions for beryllium, cobalt, indium and uranium for the three different in the 21A . 21B respectively. 21C The configurations shown and for various DC voltages were tested and the results are shown in the table below.

It can be seen from the above table of relative sensitivity measurements for the four elements that it is beneficial to the plates 3 . 4 apply an AC or RF voltage instead of or in addition to a DC bias. It appears that when applied primarily an AC or RF voltage, as in 21B which gives the best overall transmission over a wide mass range. However, it appears that by applying a combination of AC or RF voltage and DC bias, the transmission is increased over a more limited mass range. The combination of an AC or RF voltage and a DC voltage of 10 V, as in 21C , provided a transmission for uranium that was about twice as large as the one previously used for the in 20 mass spectrometer was recorded when the output of the HF-hexapole ion guide 33 next to the quadrupole mass analyzer 37 leading intermediate chamber opening 36 was arranged.

22 shows an embodiment in which the electrodes 2 on insulators 2 ' or attached to these. According to one embodiment, the insulators 2 ' Bakellite (RTM), a ceramic or a plastic such as PTFE, polyethylene, PEEK or Kapton (RTM). The electrodes 2 can be between the insulators 2 ' be interspersed or nested. According to one embodiment, the electrodes 2 on the insulators 2 ' be applied, and they may for example have electrically conductive paint. According to this embodiment, the electrode layers preferably have a thickness of about 250 μm. A particularly advantageous feature of in 22 illustrated embodiment is that it is between the electrodes 2 and the insulators 2 ' preferably there are no air gaps. Accordingly, advantageously prevents gas inside the ion guide 1a except at the entrance and at the exit of the ion guide emerges from this. In the 22 illustrated ion guide 1a is therefore particularly suitable for use as a collision or reaction cell, with gas in the ion guide 1a is initiated. A gas inlet opening may be in an upper plate electrode 3 or a lower plate electrode 4 However, the gas preferably does not pass through this opening from the ion guide 1a out. Because the in 22 illustrated ion guide 1a is considerably less leaking than embodiments in which an air gap between electrodes is present, which can be in the ion guide 1a introduced gas at a relatively high pressure, without it being necessary to use larger vacuum pumps. Similarly, as compared to other embodiments, a greater pressure differential may be conducted along the ion 1a be maintained.

Although the present invention with reference to preferred embodiments Those skilled in the art will understand that various changes are made can be made on the form and the details, without from that in the appended claims to depart from the scope of the invention.

Claims (73)

Mass spectrometer with an ion guide ( 1a . 1b . 1c ), wherein the ion guide ( 1a . 1b . 1c ) a stack of several parallel plate electrodes ( 2 ), wherein the plate electrodes ( 2 ) are formed such that curved or otherwise non-linear channels in each plate electrode ( 2 ) are provided for guiding the ions and the plate electrodes ( 2 ) are arranged parallel to the plane of ion movement, and the ion guide ( 1a . 1b . 1c ) at least one input for receiving ions along a first axis and at least one output from which ions from the ion guide ( 1a . 1b . 1c ) emerge along a second axis. The mass spectrometer of claim 1, wherein the second Axis at an angle θ to first axis and where θ> 0 °. A mass spectrometer according to claim 2, wherein θ is within of the following range: (i) <10 °, (ii) 10-20 °, (iii) 20-30 °, (iv) 30-40 °, (v) 40-50 °, (vi) 50-60 °, (vii) 60 - 70 °, (viii) 70 - 80 °, (ix) 80 - 90 °, (x) 90 - 100 °, (xi) 100 - 110 °, (xii) 110 - 120 °, (xiii) 120 - 130 °, (xiv) 130 - 140 °, (xv) 140 - 150 °, (xvi) 150 - 160 °, (xvii) 160 - 170 ° and (xviii) 170 - 180 °. A mass spectrometer according to claim 1, wherein the ion guide region ( 5 ) Is "S" -shaped. A mass spectrometer according to claim 1 or 4, wherein the first axis is parallel to the second axis. A mass spectrometer according to claim 1, 4 or 5, wherein the second axis laterally opposite the first axis is offset. The mass spectrometer of claim 5, wherein the second Axis coaxial with the first axis. A mass spectrometer as claimed in claim 7, further comprising means at least partially external to the ion guide region (12). 5 ) to block particles and / or photons passing directly from the entrance to the exit. A mass spectrometer according to claim 8, wherein the device a baffle, a plate or an electrode. Mass spectrometer according to one of the preceding claims with a second ion guide ( 1 . 1b . 1c ). A mass spectrometer according to claim 10, which further comprises a third ion guide ( 1a . 1b . 1c ) having. A mass spectrometer according to claim 11, which further comprises a fourth ion guide ( 1a . 1b . 1c ) having. Mass spectrometer according to one of claims 10 to 12, wherein either the first and / or the second and / or the third and / or the fourth ion guide ( 1a . 1b . 1c ) an ion storage area ( 10 ) having. A mass spectrometer according to claim 1, having two or more inputs for receiving ions and one or more outputs from which ions are emitted from the ion guide (10). 1a . 1b . 1c ) exit. Mass spectrometer according to claim 14, wherein the ion guide ( 1a . 1b . 1c ) two inputs for receiving ions and one output from which ions from the ion guide ( 1a . 1b . 1c ) exit. Mass spectrometer according to claim 14, wherein the ion guide ( 1a . 1b . 1c ) three inputs for receiving ions and one output from which ions from the ion guide ( 1a . 1b . 1c ) exit. A mass spectrometer according to claim 1, having one or more inputs for receiving ions and two or more outputs from which ions are emitted from the ion guide (10). 1a . 1b . 1c ) exit. Mass spectrometer according to claim 17, wherein the ion guide ( 1a . 1b . 1c ) an input for receiving ions and two outputs from which ions from the ion guide ( 1a . 1b . 1c ) exit. Mass spectrometer according to claim 17, wherein the ion guide ( 1a . 1b . 1c ) an input for receiving ions and three outputs from which ions from the ion guide ( 1a . 1b . 1c ) exit. Mass spectrometer according to claim 14 or 17, wherein the ion guide ( 1a . 1b . 1c ) at least two inputs for receiving ions and at least two outputs from which ions from the ion guide ( 1a . 1b . 1c ) exit. Mass spectrometer according to claim 14, 15, 16, 20 which further comprises at least two ion sources, wherein ions enter from a first ion source in a first input and Ions from a second ion source into a second input and wherein the first and / or the second ion source from the group selected are, which includes: (i) an electrospray ion source, (ii) an atmospheric atmospheric pressure ionization ion source, (iii) an atmospheric pressure photoionization ion source, (iv) a matrix-assisted Laser desorption ion source, (v) a laser desorption ionization ion source, (vi) an inductively coupled one Plasma ion source, (vii) an electron impact ion source, (viii) a chemical ionization ion source, (ix) an ion source with fast Atomic shot and (x) a liquid secondary ion mass spectrometry ion source. Mass spectrometer according to one of claims 14 to 21, which further comprises a first ion detector arranged to receive ions emitted from a first exit, and a second ion detector arranged to be a second one Ion output to receive exiting ions has. Mass spectrometer according to one of claims 14 to 22, which further comprises a first mass analyzer arranged is to receive ions emerging from a first exit, and a second mass analyzer arranged to be one of second ion output to receive exiting ions has. The mass spectrometer of any one of claims 14 to 21, further comprising a mass analyzer arranged to exit the ion guide (16) via a first exit. 1a . 1b . 1c ) and an ion detector which is arranged to connect via a second output from the ion guide ( 1a . 1b . 1c ) to receive leaking ions. The mass spectrometer of any one of claims 14 to 21, further comprising: an ion storage device arranged to communicate through a first exit from the ion guide (10). 1a . 1b . 1c ), wherein the ion storage device comprises a plurality of plate electrodes, wherein in a first mode of operation an ion beam enters the ion storage device via an opening and wherein in a second mode of operation an ion beam exits the ion storage device via the opening and a mass analyzer disposed to connect via a second exit from the ion guide ( 1a . 1b . 1c ) to receive leaking ions. A mass spectrometer according to claim 25, wherein the ion storage device comprises a plurality of plate electrodes ( 2 ), which are arranged parallel to the plane of ion movement. The mass spectrometer of claim 1, wherein the input has a first cross-sectional profile and a first cross-sectional area, the output having a second cross-sectional profile and a second cross-section surface, wherein the first cross-sectional profile is different from the second cross-sectional profile and / or the first cross-sectional area is different from the second cross-sectional area. The mass spectrometer of claim 27, wherein the first Cross-sectional profile and / or the second cross-sectional profile a circular or oval cross-section. The mass spectrometer of claim 27, wherein the first Cross-sectional profile and / or the second cross-sectional profile a have rectangular or square cross-section. The mass spectrometer of any one of claims 27 to 29, further comprising an ion optical device downstream of the ion guide (12). 1a . 1b . 1c ), wherein the input of the ion optical device has a fourth cross-sectional profile and a fourth cross-sectional area, wherein the second cross-sectional profile and / or the second cross-sectional area are the same as the fourth cross-sectional profile and / or the fourth cross-sectional area. The mass spectrometer of claim 30, wherein the ion optical device comprises a device selected from the group consisting of: (i) an ion guide ( 1a . 1b . 1c (ii) a quadrupole mass filter / analyzer having a circular cross-sectional profile, (iii) a transverse acceleration time-of-flight mass analyzer having a square or rectangular cross-sectional profile, (iv) a magnetic sector analyzer having a rectangular cross-sectional profile, (v) a Fourier transform ion cyclotron resonance mass analyzer ("FTICR mass analyzer") having a circular cross-sectional profile, (vi) a two-dimensional (linear) quadrupole ion trap having a circular cross-sectional profile, and (vii) a three-dimensional (Paul) quadrupole ion trap having a circular cross-sectional profile cross-sectional profile. A mass spectrometer according to any one of claims 27 to 31, wherein an ion guide region ( 5 ) between the input and the output (i) its size and / or its shape along the ion guide region ( 5 ) or (ii) has a width and / or a height whose size decreases progressively. Mass spectrometer according to one of claims 27 to 32, wherein the ion guide ( 1a . 1b . 1c ) further comprises a second input for receiving ions and / or a second output, via which ions from the ion guide ( 1a . 1b . 1c ), wherein the second input has a fifth cross-sectional profile and a fifth cross-sectional area and the second output has a sixth cross-sectional profile and a sixth cross-sectional area, the fifth cross-sectional profile being different from the sixth cross-sectional profile and / or the fifth cross-sectional area being different from the sixth cross-sectional area is different. The mass spectrometer of claim 33, wherein the first Cross-sectional profile and the first cross-sectional area and / or the second cross-sectional profile and the second cross-sectional area and / or the fifth Cross-sectional profile and the fifth Cross sectional area and / or the sixth cross-sectional profile and the sixth cross-sectional area are different are. A mass spectrometer according to any one of the preceding claims, wherein at least 50%, 60%, 70%, 80%, 90% or 95% of the plates are arranged in a first plane and the ion guide ( 1a . 1b . 1c ) is curved in the first plane. A mass spectrometer according to any one of the preceding claims, wherein at least 50%, 60%, 70%, 80%, 90% or 95% of the plates are located at an entrance of the ion guide ( 1a . 1b . 1c ) are arranged in a first plane and the ion guide ( 1a . 1b . 1c ) is curved in a second plane orthogonal to the first plane. Mass spectrometer according to one of the preceding claims, wherein at least 50%, 60%, 70%, 80%, 90% or 95% of the plates have the same distance. Mass spectrometer according to one of the preceding claims, wherein the plate electrodes have a thickness consisting of the following Group selected is: (i) less than or equal to 5 mm, (ii) less than or equal to 4.5 mm, (iii) less than or equal to 4 mm, (iv) less than or equal to 3.5 mm, (v) less than or equal to 3 mm, (vi) less than or equal to 2.5 mm, (vii) less than or equal to 2 mm, (viii) less than or equal to 1.5 mm, (ix) less than or equal to 1 mm, (x) less than or equal to 0.8 mm, (xi) less than or equal to 0.6 mm, (xii) less than or equal to 0.4 mm, (xiii) less than or equal to 0.2 mm, (xiv) less than or equal to 0.1 mm and (xv) is less than or equal to 0.25 mm. Mass spectrometer according to one of the preceding claims, wherein the plate electrodes are spaced apart from the following Group selected is: (i) less than or equal to 5 mm, (ii) less than or equal to 4.5 mm, (iii) less than or equal to 4 mm, (iv) less than or equal to 3.5 mm, (v) less than or equal to 3 mm, (vi) less than or equal to 2.5 mm, (vii) less than or equal to 2 mm, (viii) less than or equal to 1.5 mm, (ix) less than or equal to 1 mm, (x) less than or equal to 0.8 mm, (xi) less than or equal to 0.6 mm, (xii) less than or equal to 0.4 mm, (xiii) less than or equal to 0.2 mm, (xiv) less than or equal to 0.1 mm and (xv) is less than or equal to 0.25 mm. Mass spectrometer according to one of the preceding claims, wherein an alternating or HF voltage source is provided, which is connected to the plate electrodes ( 2 ) connected. Mass spectrometer according to one of the preceding claims, wherein the ion guide ( 1a . 1b . 1c ) further comprises a first outer plate electrode ( 3 ) located on a first side of the ion guide ( 1a . 1b . 1c ), and a second outer plate electrode (FIG. 4 ) located on a second side of the ion guide ( 1a . 1b . 1c ) is arranged. A mass spectrometer according to claim 41, wherein a DC voltage source is provided, comprising the first outer plate electrode ( 3 ) and / or the second outer plate electrode ( 4 ) is biased to a DC bias with respect to a mean voltage of the plate electrodes to which an AC or RF voltage is applied. Mass spectrometer according to one of claims 41 or 42, which further comprises an ion and / or gas and / or laser beam opening, those in the first outer plate electrode is arranged. Mass spectrometer according to one of claims 41 to 43, which further comprises an ion and / or gas and / or laser aperture, in the second outer plate electrode is arranged. Method for operating a mass spectrometer with the features according to claim 10, 11 or 12, wherein in an operating mode the first ion guide ( 1a . 1b . 1c ) and the second ion guide ( 1a . 1b . 1c ) are held at different DC potentials, so that from the first ion guide ( 1a . 1b . 1c ) exiting ions into the second ion guide ( 1a . 1b . 1c ). Method for operating a mass spectrometer having the features of claim 11 or 12, wherein in an operating mode the second ion guide ( 1a . 1b . 1c ) and the third ion guide ( 1a . 1b . 1c ) are held at different DC potentials, so that from the second ion guide ( 1a . 1b . 1c ) leaking ions into the third ion guide ( 1a . 1b . 1c ). A method of operating a mass spectrometer having the features of claim 12, wherein in an operating mode the third ion guide ( 1a . 1b . 1c ) and the fourth ion guide ( 1a . 1b . 1c ) are held at different DC potentials, so that from the third ion guide ( 1a . 1b . 1c ) exiting ions into the fourth ion guide ( 1a . 1b . 1c ). Method for operating a mass spectrometer having the features according to claim 10, 11 or 12, wherein in an operating mode the second ion guide ( 1a . 1b . 1c ) on one of those of the first ion guide ( 1a . 1b . 1c ) holding different DC potential, so that ions in the first ion guide ( 1a . 1b . 1c ). Method for operating a mass spectrometer having the features of claim 11 or 12, wherein in an operating mode the third ion guide ( 1a . 1b . 1c ) on one of those of the second ion guide ( 1a . 1b . 1c ) holding different DC potential, so that ions in the second ion guide (1a, 1b . 1c ). A method of operating a mass spectrometer having the features of claim 12, wherein in an operating mode the fourth ion guide ( 1a . 1b . 1c ) on one of those of the third ion guide ( 1a . 1b . 1c ) is held at different DC potential, so that ions in the third ion guide ( 1a . 1b . 1c ). Method for operating a mass spectrometer having the features of claim 13, wherein in a first operating mode the ion storage area ( 10 ) Receives ions through a single orifice and in a second mode of operation, ions from the ion storage region (FIG. 10 ) through the single opening. A method of operating a mass spectrometer having the features of any one of claims 14 to 21, wherein in use, a probe is inserted into the ion guide ( 1a . 1b . 1c ) is split into two or more beams, wherein the first beam via a first output from the ion guide ( 1a . 1b . 1c ) and the second jet via a second exit from the ion guide ( 1a . 1b . 1c ) exit. The method of claim 52, wherein, in use, the into an input of the ion guide ( 1a . 1b . 1c ) entering through one or more electrodes, which are arranged adjacent to the input, one or more electrodes, which within the ion guide ( 1a . 1b . 1c ) or one or more electrodes adjacent to an exit of the ion guide ( 1a . 1b . 1c ) are divided into two or more beams. A method according to any one of claims 52 or 53, wherein at least a part of one into the ion guide ( 1a . 1b . 1c ) entering ion beam to or between one of several outputs is switchable. The method of claim 54, wherein, in use, the into an input of the ion guide ( 1a . 1b . 1c ) entering through either one or more electrodes disposed adjacent to the input, or one or more electrodes disposed within the ion guide (FIG. 1a . 1b . 1c ) or one or more electrodes adjacent to an exit of the ion guide ( 1a . 1b . 1c ), are switchable to or between one of a plurality of outputs. A method of operating a mass spectrometer having the features of claim 1, wherein in a first mode of operation an ion beam is introduced via a first opening into the ion guide (10). 1a . 1b . 1c ) and via a second opening from the ion guide ( 1a . 1b . 1c ) and wherein in a second mode of operation, an ion beam via the second opening in the ion guide ( 1a . 1b . 1c ) entry. The method of claim 56, wherein in the second mode of operation, the ion beam is directed across the first opening of the ion guide (10). 1a . 1b . 1c ) exit. The method of claim 56, wherein in the second mode of operation, the ion beam is separated from the ion guide by a third orifice other than the first and second apertures. 1a . 1b . 1c ) exit. Method for operating a mass spectrometer with the features of claim 40, wherein adjacent plate electrodes opposite phases of the AC or RF voltage can be supplied. A method of operating a mass spectrometer having the features of any one of claims 1 to 44, wherein one or more of the plate electrodes are held in use at a different DC potential from the other plate electrodes so that multiple discrete ion guide regions within the ion guide ( 1a . 1b . 1c ) are formed. Method for operating a mass spectrometer with the features of any one of claims 1 to 44, wherein a plurality the plate electrodes at different DC potentials being held. The method of claim 61, wherein the ion guide ( 1a . 1b . 1c ) has a first outer portion, a second outer portion and an intermediate portion between the first and second outer portions, and wherein the DC potential on which the plate electrodes are held increases in the first and / or second outer portions with respect to the intermediate portion is such that ions to a central region of the ion guide ( 1a . 1b . 1c ) are returned. Method for operating a mass spectrometer with the features of any one of claims 1 to 44, wherein one or several transient DC potentials or one or more DC potential waveforms applied to the plate electrodes are. The method of claim 63, wherein the one or more transient DC potentials or the one or more DC potential waveforms comprises ions from a region of the ion guide (10). 1a . 1b . 1c ) into another region of the ion guide ( 1a . 1b . 1c ). Method for operating a mass spectrometer having the features according to one of claims 1 to 44, wherein the ion guide ( 1a . 1b . 1c ) is maintained in use at a pressure selected from the group consisting of: (i) greater than or equal to 0.0001 mbar, (ii) greater than or equal to 0.0005 mbar, (iii) greater than or equal to 0.001 mbar, (iv) greater than or equal to 0.005 mbar, (v) greater than or equal to 0.01 mbar, (vi) greater than or equal to 0.05 mbar, (vii) greater than or equal to 0.1 mbar, (viii ) greater than or equal to 0.5 mbar, (ix) greater than or equal to 1 mbar, (x) greater than or equal to 5 mbar and (xi) greater than or equal to 10 mbar. Method for operating a mass spectrometer having the features according to one of claims 1 to 44, wherein the ion guide ( 1a . 1b . 1c ) is maintained in use at a pressure selected from the following group: (i) less than or equal to 10 mbar, (ii) less than or equal to 5 mbar, (iii) less than or equal to 1 mbar, (iv) less than or equal to equal to or less than 0.5 mbar, (v) less than or equal to 0.1 mbar, (vi) less than or equal to 0.05 mbar, (vii) less than or equal to 0.01 mbar, (viii) less than or equal to 0.005 mbar, (ix ) less than or equal to 0.001 mbar, (x) less than or equal to 0.0005 mbar and (xi) less than or equal to 0.0001 mbar. Method for operating a mass spectrometer having the features according to one of claims 1 to 44, wherein the ion guide ( 1a . 1b . 1c ) is maintained in use at a pressure selected from the following group: (i) between 0.0001 and 10 mbar, (ii) between 0.0001 and 1 mbar, (iii) between 0.0001 and 0, 1 mbar, (iv) between 0.0001 and 0.01 mbar, (v) between 0.0001 and 0.001 mbar, (vi) between 0.001 and 10 mbar, (vii) between 0.001 and 1 mbar, (viii) between 0.001 and 0.1 mbar, (ix) between 0.001 and 0.01 mbar, (x) between 0.01 and 10 mbar, (xi) between 0.01 and 1 mbar, (xii) between 0.01 and 0.1 mbar, (xiii) between 0.1 and 10 mbar, (xiv) between 0.1 and 1 mbar and (xv) between 1 and 10 mbar. A method according to claim 59 or for operating a mass spectrometer having the features of any one of claims 1 to 40, wherein the ion guide (16) 1a . 1b . 1c ) is maintained in use at a pressure selected from the group consisting of: (i) greater than or equal to 1 × 10 ^-7 mbar, (ii) greater than or equal to 5 × 10 ^-7 mbar, (iii) greater than or equal to 1 × 10 ^-6 mbar, (iv) greater than or equal to 5 × 10 ^-6 mbar, (v) greater than or equal to 1 × 10 ^-5 mbar and (vi) greater than or equal to 5 × 10 ^-5 mbar. A method according to claim 59 or for operating a mass spectrometer having the features of any one of claims 1 to 40, wherein the ion guide ( 1a . 1b . 1c ) is maintained in use at a pressure selected from the group consisting of: (i) less than or equal to 1 × 10 ^-4 mbar, (ii) less than or equal to 5 × 10 ^-5 mbar, (iii) less than or equal to 1 × 10 ^-5 mbar, (iv) less than or equal to 5 × 10 ^-6 mbar, (v) less than or equal to 1 × 10 ^-6 mbar, (vi) less than or equal to 5 × 10 ^-7 mbar and (vii) smaller or equal to 1 × 10 ^-7 mbar. A method according to claim 59 or for operating a mass spectrometer having the features of any one of claims 1 to 40, wherein the ion guide ( 1a . 1b . 1c ) is maintained in use at a pressure selected from the following group: (i) between 1 × 10 ^-7 and 1 × 10 ^-4 mbar, (ii) between 1 × 10 ^-7 and 5 × 10 ^-5 (iii) between 1 × 10 ^-7 and 1 × 10 ^-5 mbar, (iv) between 1 × 10 ^-7 and 5 × 10 ^-6 mbar, (v) between 1 × 10 ^-7 and 1 × 10 ^{. 6} mbar, (vi) between 1 × 10 ^-7 and 5 × 10 ^-7 mbar, (vii) between 5 × 10 ^-7 and 1 × 10 ^-4 mbar, (viii) between 5 × 10 ^-7 and 5 × 10 ^-5 mbar, (ix) is between 5 × 10 ^-7 and 1 x 10 ^-5 mbar, (x) is between 5 × 10 ^-7 and 5 × 10 ^-6 mbar, (xi) is between 5 × 10 ^-7 to 1 × 10 ^-6 mbar, (xii) between 1 × 10 ^-6 and 1 × 10 ^-4 mbar, (xiii) between 1 × 10 ^-6 and 5 × 10 ^-5 mbar, (xiv) between 1 × 10 ^-6 and 1 X 10 ^-5 mbar, (xv) between 1 × 10 ^-6 and 5 × 10 ^-6 mbar, (xvi) between 5 × 10 ^-6 and 1 × 10 ^-4 mbar, (xvii) between 5 × 10 ^-6 and 5 x 10 ^-5 mbar, (xviii) is between 5 × 10 ^-6 and 1 x 10 ⁵ mbar, (xix) is between 1 × 10 ^-5 and 1 x 10 ^-4 mbar, (xx) between 1 × 10 ^-5 and 5 × 10 ^-5 mbar and (xxi) is between 5 × 10 ^-5 and 1 x 10 ^-4 mbar. sMethod for operating a mass spectrometer with the features of claim 41, wherein the first outer plate electrode and / or the second outer plate electrode a pure DC voltage is applied. Method for operating a mass spectrometer with the features of claim 41, wherein the first outer plate electrode and / or the second outer plate electrode a pure AC or RF voltage is applied. Method for operating a mass spectrometer with the features of claim 41, wherein the first outer plate electrode and / or the second outer plate electrode a DC voltage and an AC or RF voltage applied is.