CLEANING ION OPTIC MULTIPOLE DEVICES

Abstract

A cleaning device for cleaning electrodes of an ion optical multipole device comprises at least one substantially longitudinal cleaning section, at least one handling section extending axially from the at least one cleaning section and at least one direction section extending axially from the at least one cleaning section. The at least one cleaning section has a larger cross section than the at least one handling section. The at least one direction section is capable of allowing a longitudinal movement of the cleaning device in a first axial direction and resisting a longitudinal movement of the cleaning device in a second, opposite axial direction

Claims

1. A cleaning device for cleaning multiple elongate electrodes of an ion optical multipole device, the cleaning device comprising at least one substantially longitudinal cleaning section, at least one handling section extending axially from the at least one cleaning section and at least one direction section extending axially from the at least one cleaning section, wherein the at least one cleaning section has a larger cross section than the at least one handling section and the at least one direction section is capable of allowing a longitudinal movement of the cleaning device in a first axial direction and resisting a longitudinal movement of the cleaning device in a second, opposite axial direction.

2. The cleaning device according to claim 1, wherein at least one cleaning section has a substantially polygonal cross-sectional shape, such as square, hexagonal or octagonal.

3. The cleaning device according to claim 1, wherein at least one cleaning section has a substantially circular cross-sectional shape.

4. The cleaning device according to claim 1, wherein at least one cleaning section has a substantially elliptical cross-sectional shape.

5. The cleaning device according to claim 1, comprising at least two cleaning sections, wherein two cleaning sections have different cross-sectional shapes and/or different cross-sectional dimensions.

6. The cleaning device according to claim 1, comprising at least two cleaning sections, wherein two cleaning sections have identical cross-sectional shapes and/or cross-sectional dimensions.

7. The cleaning device according to claim 1, comprising two or more cleaning sections separated by at least one spacing section, wherein the at least one spacing section has a smaller cross section than the cleaning sections.

8. The cleaning device according to claim 1, wherein at least one cleaning section comprises a series of cleaning elements protruding from a body.

9. The cleaning device according to claim 8, wherein the cleaning elements comprise cleaning flanges.

10. The cleaning device according to claim 9, wherein at least some cleaning flanges protrude from the body substantially perpendicularly.

11. The cleaning device according to claim 9, wherein at least some cleaning flanges protrude from the body at an acute angle.

12. The cleaning device according to claim 9, wherein at least some cleaning flanges are substantially planar.

13. The cleaning device according to claim 9, wherein at least some cleaning flanges are curved.

14. The cleaning device according to claim 1, wherein at least one cleaning section is arranged to be compressible.

15. The cleaning device according to claim 1, wherein at least one cleaning section is capable of absorbing and releasing a cleaning liquid.

16. The cleaning device according to claim 1, wherein at least one cleaning section comprises cellulose, natural or artificial sponge, leather and/or cloth.

17. The cleaning device according to claim 1, comprising three cleaning sections separated by spacing sections.

18. The cleaning device according to claim 1, wherein the direction section comprises at least one flexible element protruding from the body and at least one blocking element arranged adjacent the flexible element for blocking any bending of the flexible element in the direction of the blocking element.

19. The cleaning device according to claim 18, wherein the flexible element comprises a flange having a larger cross section than the blocking element.

20. The cleaning device according to claim 1, wherein the at least one handling section is substantially longer than the cleaning sections combined.

21. The cleaning device according to claim 20, wherein the handling section comprises a substantially stiff rod.

22. The cleaning device according to claim 20, wherein the handling section comprises a substantially flexible element, such as a cord or rope.

23. The cleaning device according to claim 1, comprising two handling sections, wherein one handling section at one end of the cleaning sections is at least five times as long as the other handling section at the opposite end of the one or more cleaning sections, preferably at least ten times as long.

24. The cleaning device according to claim 1, wherein at least one handling section has a length exceeding the length of the electrodes to be cleaned.

25. The cleaning device according to claim 1, wherein at least one cleaning section has a cross-section exceeding the inscribed diameter of the electrodes to be cleaned.

26. A method of cleaning electrodes of an ion optical multipole device, the method comprising the use of a cleaning device according to claim 1.

27. The method according to claim 26, further comprising using at least one cleaning liquid to be applied to the at least one cleaning section of the cleaning device.

28. A method of cleaning electrodes of an ion optical multipole device, the method comprising the use of a cleaning device comprising one substantially longitudinal cleaning section, at least one handling section extending axially from the at least one cleaning section and at least one further cleaning section, wherein the one substantially longitudinal cleaning section has a larger cross section than the at least one handling section and the method further comprising using at least two different cleaning liquids to be applied to at least two respective cleaning sections of the cleaning device.

29. The method according to claim 28, wherein at least one cleaning liquid comprises water, either substantially pure water or water containing a soap, a solvent or another cleaning enhancing substance.

30. The method according to claim 28, wherein at least one cleaning liquid comprises a solvent.

31. The method according to claim 30, wherein the solvent is hydrophobic.

32. The method according to claim 30, wherein the solvent is hydrophilic.

33. The method according to claim 28, wherein the cleaning device comprises at least three consecutive cleaning sections, wherein water is applied to the first cleaning section, a solvent is applied to the second cleaning section and no liquid is applied to the third cleaning section.

34. The method according to claim 28, comprising inserting the cleaning device, with a handling section first, into one end of a spacing between electrodes of an ion optical multipole device, passing the cleaning device through the spacing so that the handling section protrudes from the spacing at its other end, and pulling the cleaning device from the spacing at said other end.

35. The method according to claim 28, wherein the ion optical multipole device is a quadrupole device, a hexapole device, an octopole device or another multipole device.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0033] FIG. 1 shows, in a side view, an exemplary embodiment of a cleaning device according to the invention.

[0034] FIG. 2 schematically shows, in a cross-sectional view, how a cleaning device according to the invention can be inserted between the electrodes of an ion optical multipole device.

[0035] FIG. 3 schematically shows, in front view, the space between the electrodes of an ion optical multipole device.

[0036] FIG. 4 schematically shows, in a perspective view, part of an exemplary embodiment of a cleaning device according to the invention.

[0037] FIG. 5 schematically shows, in a cross-sectional view, an alternative embodiment of a cleaning section of a cleaning device according to the invention.

[0038] FIGS. 6A-6D schematically show, in front view, various embodiments of cleaning sections of a cleaning device according to the invention.

[0039] FIGS. 7A & 7B schematically show alternative embodiments of a cleaning device according to the invention.

[0040] FIG. 8 schematically shows how different liquids may be applied to a cleaning device according to the invention.

[0041] FIG. 9 schematically shows an exemplary embodiment of a cleaning method according to the invention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0042] The exemplary embodiment of a cleaning device 1 according to the invention which is schematically illustrated in FIG. 1 comprises various sections having different functions. The cleaning device 1 shown has three cleaning sections 20, two handling sections 30, three spacing sections 40, a direction section 50 and a connection section 60. The cleaning sections 20 serve to clean the surfaces of multipole device electrodes, the handling sections 30 serve to handle the cleaning device 1, the spacing sections 40 serve to space the cleaning sections 20 apart, the direction section 50 serves to impose a preferred direction-of-use upon the cleaning device 1, while the connection section 60 serves to releasably connect one handling section, which in this embodiment is the longest handling section, to the other sections of the device.

[0043] The cleaning device 1 is shown to have a body constituted by a longitudinal shaft 10 which extends from the first handling section 30 to the connection section 60, through the intermediate cleaning sections 20, spacing sections 40 and direction section 50. The longitudinal shaft 10 may consist of a single piece of material, for example plastic or metal. It can be seen in the example shown that the shaft 10 has a smaller cross-sectional diameter than all other parts of the cleaning device 1.

[0044] In the embodiment shown in FIG. 1, handling sections 30 are provided at both ends of the device 1. In this embodiment, one handling section is considerably longer than the other handling section. In particular, a relatively short handle 31 constitutes the handling section bordering the direction section 50, while a relatively long handle 32 (of which only a part is shown) is connected via the connection section 60. The relatively short handle 31 may have a length of, for example, between 1 and 5 cm, such as 1.5 or 2 cm, while the relatively long handle 32 may have a length of, for example, between 20 cm and 50 cm, for example approximately 35 cm or 40 cm. As the relatively long handle 32 serves to pull the device 1 through an ion optical multipole device or other mass spectrometer component having longitudinal electrodes, its length should be such that the total length of the device 1 is at least be equal to the length of the electrodes to be cleaned but preferably greater. Thus, if the electrodes to be cleaned have a length of 40 cm, for example, the length of the cleaning device 1 should be more than 40 cm, for example 50 cm. Preferably, the length of the longest handle (32 in the example shown) should be at least equal to the length of the electrodes to be cleaned, or even at least equal to the length of the multipole device, if the multipole device has a greater length than its electrodes. The person skilled in the art will therefore select a suitable handle length dependent on the length of the electrodes and/or the multipole device to be cleaned.

[0045] The cross-sectional diameter of the handles 31 and 32 is in the embodiment shown greater than the cross-sectional diameter of the shaft 10 but smaller than the cross-sectional diameter of the cleaning sections 20. Having a smaller cross-sectional diameter than the cleaning sections avoids any unnecessary friction to be caused by the handles.

[0046] Embodiments can be envisaged in which a handling section is provided at one end of the device only. However, having a handle at both ends of the device makes the device easier to use. The handles may be made of plastic, for example.

[0047] In the embodiment shown, the cleaning device 1 has three cleaning sections 20. In some embodiments, the device may have less or more cleaning sections, for example only one or two cleaning sections, or four or more cleaning sections. Having at least three cleaning sections provides advantages for certain applications, as will be explained later.

[0048] In the embodiment of FIG. 1 each cleaning section 20 comprises a series of flanges 21 which extend substantially perpendicularly from the shaft 10 which constitutes the body of the cleaning device 1. The flanges 21 of each cleaning section are spaced apart so as to allow them to bend when in use. The mutual spacing of the flanges within each cleaning section is, in the embodiment shown, greater than the thickness of the flanges, to allow bending of the flanges 21. It has been found that cellulose is a particularly suitable material for the flanges 21. However, other materials, such as leather, cloth and/or sponge (either artificial or natural) may also be used. Suitable materials may be able to absorb liquid to some extent and release the liquid when the cleaning device is inserted into the internal channel of a multipole device.

[0049] As can be seen, the flanges 21, when not in use, have a greater cross-sectional diameter than all other parts of the device 1. This ensures that in use other parts of the device will not make contract with the electrodes to be cleaned and will therefore cause no unnecessary friction or damage.

[0050] In the embodiment of FIG. 1, all three cleaning sections 20 have a similar structure of about six to ten flanges each, the cleaning section 20 nearest to the handle 31 having the largest number of flanges. The number of flanges per cleaning section may range from about four to about twenty and is preferably about ten to fifteen. The cleaning sections 20 may have mutually different structures. For example, only one or two cleaning sections could have flanges, while one or more other cleaning sections may have another structure, for example one without flanges, such as a tubular compressible structure. Such a tubular compressible structure may be made of cellulose, foam or leather, for example. In some embodiments, all cleaning sections may have another structure than shown in FIG. 1 and may for example have no flanges, although flanges have been shown to be effective. Structures having a similar effect to flanges, such as ribbed resilient structures, may alternatively or additionally be used. The cleaning sections 20 have in the embodiment shown identical cross-sectional diameters, but this is not necessary. In some embodiments, therefore, the cross-sectional diameters of the cleaning sections may vary between and/or within sections.

[0051] The cleaning sections 20 are spaced apart by spacing sections 40 which, in the embodiment shown, each comprise a spacing element 41. The spacing elements 41 may be constituted by tubular elements through which the shaft 10 passes, or by widened parts of the shaft 10, for example. The spacing sections 40 serve to facilitate applying any liquids to the cleaning sections and to provide a time delay between the use of the various liquids when the cleaning device is passed between electrodes.

[0052] The direction section 50, which provides a preferred direction D in which the device 1 may be passed between electrodes, is shown to comprise a flange 51 and a blocking element 52. The flange is flexible and may therefore bend when the device is used, but due to the blocking element 52, which is arranged immediately adjacent the flange 51, the flange can bend in one direction only, away from the blocking element 52. As a result, the flange 51 will cause little friction when bent away from the blocking element 52 but significantly more friction when bent towards the blocking element 52. In this way, a preferred direction-of-use D is obtained.

[0053] A direction section 50 may comprise more than one flange 51 and more than one blocking element 52. The cross-sectional diameter of the flange 51 may be identical to the cross-sectional diameter of the flanges 21, but may also differ, for example be greater so that the directional effect is greater.

[0054] In an embodiment, the diameter of a flange 21 may be approximately 9 mm, while a spacing section has a diameter of approximately 7 mm and the body 10 may have a diameter of approximately 4 mm. Other diameters are of course possible, and the outer cross-sectional diameter of the flanges 21 will depend on the dimensions of the ion optical multipole device to be cleaned, in particular on the diameter of the internal channel defined by the electrodes.

[0055] A connection section 60 connects the handle 32 with the body 10 of the device. The connection section 60 comprises a connection element 61 which may contain a screw thread so that the handle 32 can be removable. In some embodiments the handle 32 may be integrally formed with the body 10, in which case the connection section 60 is omitted. In some embodiments, the further spacing element 41 adjacent the connection section may be omitted. In some embodiments, therefore, the handle 32 may be arranged immediately adjacent a cleaning section 20.

[0056] FIG. 2 schematically illustrates how a cleaning device according to the invention may be used to clean electrodes of an ion optical multipole device, such as a mass filter or similar device. A cleaning device 1 is passed between electrodes 100 of an ion optical multipole device in a forward direction D. As the cleaning device 1 enters the space (that is, the internal channel) between the electrodes 100, the flanges 21 of the cleaning device 1 are bent so that they press against the outer surfaces of the electrodes. This pressure increases the contact surface area between the flanges 21 and the electrodes 100 and improves the cleaning action of the flanges.

[0057] It can also be seen from FIG. 2 that the overall length of the cleaning device 1 should be at least equal to the overall length of the electrodes 100, but that preferably a handle of the cleaning device 1 should be longer than the electrodes, so as to allow an easy handling of the cleaning device.

[0058] FIG. 3 is a front view of electrodes 100, in the case shown a quadrupole arrangement. The dimensions of the circular space between the electrodes are defined by the so-called inscribed diameter, which is twice the so-called inscribed radius r0. A circle having a diameter equal to twice the inscribed radius r0 will fit exactly between the electrodes 100. Referring to FIG. 2 again, it will be clear that a cleaning device having a cross-sectional diameter equal to twice the inscribed radius r0 will not exert any significant force on the electrodes 100. For this reason, the cross-sectional diameter of the cleaning sections of the cleaning device should in use be larger than the inscribed diameter, for example at least 5% larger, but preferably at least 10% larger. The extent to which the cross-sectional diameter of the cleaning device exceeds the inscribed diameter may also depend on the material of the cleaning sections. Cleaning sections made of softer materials and/or materials having a low resilience may need to exceed the inscribed diameter by a greater amount than harder materials and/or materials having a high resilience, for example. Cleaning sections on which a liquid is applied before use may swell due to absorption of the liquid and may, when dry, not exceed the inscribed diameter. Other cleaning sections may shrink due to the application of a liquid, in which case their diameters, when dry, should exceed the inscribed diameter.

[0059] One end of a cleaning device 1 according to the invention is shown in more detail in FIG. 4. The cleaning device 1 is shown to comprise a cleaning section 20 having flanges 21, a direction section comprising a flange 51 and a blocking element 52, and a handle 31. It can be seen that the direction section flange 51 is arranged immediately adjacent the blocking element 52, thus preventing the flange 51 to bend towards the blocking element 52. As can be seen, the flange 51 is capable of bending the other way, away from the blocking element 52. Although only a single direction section is shown in FIGS. 1 and 4, in some embodiments more than one direction section may be provided, for example two, three or four direction sections, to increase the directional preference of the device and to avoid inserting the device in the incorrect direction.

[0060] In FIG. 4, both the direction section flange 51 and the cleaning section flanges 21 are shown to consist of substantially flat discs which extend substantially perpendicularly from the body 10 of the device 1. However, this is not essential and in other embodiments, the flanges may have different shapes and/or may extend at another angle than approximately 90 from the body of the cleaning device. The angle at which flanges, or other objects, may protrude from the body may be less than 90, for example between approximately 30 and 60, for example approximately 45.

[0061] An example of flanges extending at another angle than 90 is shown in FIG. 5, where flanges 21 extend at an angle of approximately 45 from the body 10 of the cleaning device 1 (of which for the sake of clarity of the drawing only part is shown). In the embodiment shown, the flanges 21 are not constituted by substantially flat discs but by substantially conical structures. In such an embodiment, the flanges 21 provide a preferred direction of insertion, in which case the direction section (50 in FIG. 1) may be omitted. However, in some embodiment both flanges providing a preferred direction and a direction section may be present.

[0062] In some embodiments, at least one cleaning section may not have flanges but may have an alternative structure, for example consisting of a tubular sheath of a suitable material, such as cellulose, foam or leather.

[0063] Examples of various cross-sectional shapes of cleaning sections and/or their flanges are schematically illustrated in FIGS. 6a to 6D. FIG. 6A shows a substantially circular cross-section of a flange 21 arranged on a body 10. The advantage of this cross-sectional shape is that it is suitable for cleaning various electrode arrangements, such as quadrupoles, hexapoles and octopoles, for example. The embodiment of FIG. 6B, having a basically square cross-sectional shape from which the four corners have been replaced with concave cut-outs, is particular suitable for cleaning a quadrupole arrangement as it will be able to reach a larger part of the surface of the quadrupole electrodes.

[0064] The substantially square cross-sectional shape of the embodiment of FIG. 6C is also suitable for cleaning quadrupole devices. The substantially hexagonal cross-sectional shape of the embodiment of FIG. 6D is particularly suitable for cleaning hexapole arrangements. It will be understood that other cross-sectional shapes are also possible.

[0065] The embodiment of the cleaning device shown in FIG. 1 has three cleaning sections (20 in FIG. 1). As mentioned above, other embodiments may have more or less than three cleaning sections. The exemplary embodiment of FIG. 7A, for example, has two cleaning sections 20, but is otherwise identical to the embodiment of FIG. 1. The exemplary embodiment of FIG. 7B has only a single cleaning section 20 but is also otherwise identical to the embodiment of FIG. 1.

[0066] A particular advantageous use of the cleaning device of the invention is illustrated by FIG. 8, in which a cleaning device 1 according to the invention is shown to comprise a first handle 31, a direction section 50, cleaning sections 20, spacing elements 41 and a second handle 32 (of which only part is shown). In the embodiment shown, the device 1 comprises three cleaning sections 20 which have no flanges but are constituted by tubes of absorbing material, such as foam or leather. The use of the cleaning device illustrated in FIG. 8 is equally well possible with a cleaning device of which at least one cleaning section comprises flanges, for example.

[0067] Advantageously, the device 1 is used together with a water supply 210 and a solvent supply 220. The direction section 50 is arranged in such a way that the preferred direction of insertion of the device between electrodes of an ion optical multipole device is with the (second) handle 32 first, so in the direction D. Water is applied to the first cleaning section 20A which is to be in contact with the electrodes, while a solvent is applied to the second cleaning section 20B. The cleaning sections 20A and 20B are therefore arranged to absorb some liquid and are made of a liquid absorbing material. In the embodiment shown, no liquid is applied to the third cleaning section 20C, although in some embodiments a third liquid may be applied to the third cleaning section 20C.

[0068] When the device 1 is inserted in the space between electrodes (see FIG. 2, for example), the compression of the cleaning sections by the electrodes of the multipole device leads to at least some release of the respective absorbed liquid. Thus, in the embodiment shown, first the water is applied to the electrodes, then the water is replaced with solvent, and subsequently the electrodes are dried by the dry cleaning section, that is, the cleaning section 20C to which no liquid was applied.

[0069] It will be understood that the invention is not limited to applying two liquids and using a single dry cleaning section. Only a single liquid may be applied on a single cleaning section, one other cleaning section being used for drying. When using a device having only a single cleaning section, the drying may be dispensed with.

[0070] The solvent may be a suitable organic solvent (that is, a carbon-based solvent) such as an alcohol, ether, or ester, an aliphatic or aromatic solvent, or any other suitable solvent. The water may be distilled high-purity water. In some embodiments, the cleaning liquids are mixtures of water and a solvent, with various mixing ratios. Cleaning liquids, such as water, may contains surfactants. Cleaning liquids containing surfactants are preferably followed by pure water and are preferably then followed by a solvent.

[0071] Solvents may be selected on the basis of their compatibility with the materials from which the cleaning device is made, and vice versa.

[0072] The exemplary embodiment of a method 300 according to the invention which is schematically illustrated in FIG. 9 starts at step 301 when the method is initiated. At step 302, a first cleaning liquid, such as a water, is applied to a first cleaning section of a cleaning device according to the invention, as discussed above with reference to FIG. 8. At step 303, a second cleaning liquid, such as a solvent, is applied to a second cleaning section. In this embodiment, no liquid or other substance is applied to a third cleaning section of the device, if present. This concludes the preparation of the cleaning device.

[0073] At step 304, the cleaning device is inserted into the space between the electrodes of an ion optical multipole device or similar device. It is inserted so far that one end of the cleaning device emerges at the far end of the electrodes, so that the cleaning device can be passed through the space between the electrodes of the multipole device at step 305.

[0074] These steps may be carried out more than once, for example two, three, four, five or more than five times, such as ten times or even fifty times. The steps 304 and 305 may be carried out as many times as necessary to get a certain result, which may be determined by visual detection or automatic detection (involving image processing, for example). In a preferred embodiment, a predetermined number of iterations is carried out, preferably three. Each time the cleaning device emerges from the multipole device, at step 306 it is checked whether the predetermined number of iterations has been reached. If this is the case (Yes), the method ends at step 307. If the predetermined number of iterations has not been reached (No), the method returns to step 304 where the cleaning device is inserted into the multipole device. In some embodiments, not only steps 304 and 305 may be repeated, but steps 302 (applying the first cleaning liquid) and 303 (applying the second cleaning liquid) as well. In some embodiments, therefore, step 302 may follow a No decision in step 306. In certain embodiments, a No decision in step 306 leads back to step 302 if a first condition is fulfilled (for example an even number of iterations has been carried out) and leads back to step 304 if a second condition is fulfilled (for example an odd number of iterations has been carried out). This results in cleaning liquids being applied, but not each time the cleaning device is inserted into the multipole arrangement. Other variants of the method of the invention are also possible.

[0075] After cleaning the electrodes of a multipole device, the cleaning device may be discarded. Some embodiments of the cleaning device may be suitable for multiple use.

[0076] This embodiment of the method according to the invention is given by way of example only. It will therefore be understood by those skilled in the art that the invention is not limited to the embodiments described above and that many additions and modifications may be made without departing from the scope of the invention as defined in the appending claims.