WO2013178806A2

WO2013178806A2 - Light guide device for an ionization apparatus, and method for ionizing atoms and/or molecules

Info

Publication number: WO2013178806A2
Application number: PCT/EP2013/061312
Authority: WO
Inventors: Martin Sklorz; Ralf Zimmermann
Original assignee: Helmholtz Zentrum München
Priority date: 2012-06-01
Filing date: 2013-05-31
Publication date: 2013-12-05
Also published as: WO2013178806A3; DE102012209324A1

Abstract

The invention relates to a light guide device (10) for an ionization apparatus (32), comprising a light conducting unit (12) that has a wall (20) which extends along a longitudinal direction (14) from a light incidence section (16) of the light conducting unit (12) to a light emergence section (18) of the light conducting unit (12). A light-conducting cavity (22), inside which an internal atmosphere can be set, is formed within the wall (20). At least radiation (24) in a partial ultraviolet region and/or partial vacuum ultraviolet region can be guided through said internal atmosphere. The light guide device (10) can be arranged on a through-hole (34) in an ionization chamber wall (36) in such a way that at least a portion of the light conducting unit (12) protrudes into the ionization chamber and in an operating position, the light emergence section (18) of the light conducting unit (12) can be adjusted to a pressure reduction unit (38) of the ionization chamber. The invention further relates to a method for ionizing atoms and/or molecules.

Description

Optical fiber device for an ionization device and method for ionizing atoms and / or molecules

The present invention relates to a

Optical fiber device for an ionization device. Of

Furthermore, the present invention relates to a method for ionizing atoms and / or molecules.

In US 7, 109, 476 B2 is a detection device, which

for example, may be formed as a mass spectrometer described. The detection device has a plurality of ion sources for atmospheric pressure photoionization. In particular, the detection device should have an electrostatic ionizer and a photoionizer, both of which should be designed for ionization at atmospheric pressure.

Frequently, ultraviolet light (ultraviolet light), especially vacuum ultraviolet light (vacuum ultraviolet light), is used to ionize atoms and / or molecules

prefers. However, the ionization of atoms and / or molecules with ultraviolet light, especially with

Vacuum ultraviolet light, often hardly / not feasible, since the ultraviolet light or vacuum ultraviolet light is already absorbed before reaching an ionization site of the atoms to be ionized and / or molecules from its environment.

The object of the present invention is therefore to improve the possibility of using ultraviolet light, in particular vacuum ultraviolet light for ionizing atoms and / or molecules.

The object is achieved by a light guide device for an ionization device having the features of claim 1, an ionization device having the features of claim 11, a spectrometer having the features of claim 13, a A method for ionizing atoms and / or molecules with the features of claim 14 and a method for

Detecting atoms and / or molecules having the features of claim 15.

The present invention is based on the basic idea that by introducing the radiation of the ultraviolet partial spectral region to a preferred ionization site via the optical fiber device, absorption of the ultraviolet partial spectral region radiation through an environment of the ionization site can be reliably minimized / prevented. In particular, by means of the optical fiber device, it is possible to supply vacuum ultraviolet light to the atoms and / or molecules to be ionized such that undesired interaction of the vacuum ultraviolet light with non-ionizable molecules / ions can be minimized. The

The present invention thus effects a targeted ionization of only the desired atoms and / or molecules, while the conventionally often occurring interaction of the light used for the ionization with matrix atoms / matrix molecules can be prevented.

The present invention thus causes a

Negligible matrix dependence in ionizing atoms and / or molecules. In addition, it is also possible by means of the present invention to ionize non-polar compounds and / or compounds with a high ionization potential (IP), such as, for example, aliphatic compounds (directly via photoionization).

The present invention thus realizes a light guide, by means of which radiation of an ultraviolet spectral range, in particular of a vacuum ultraviolet spectral range, within the light guide device along a path at least partially through a

Ionisierungskammer is feasible without a unwanted absorption of the guided radiation while passing along the path is to be feared.

It should be noted that the present invention also relates to ionization by means of a vacuum ultraviolet

Light at an atmospheric pressure is applicable. The vacuum ultraviolet light can only close to the

Pressure reduction can be supplied. The photoions formed can then be passed within milliseconds through an aperture (e.g., skimmer aperture, aperture, capillary aperture, or so-called ion guide) into lower pressure ranges. Alternatively, the direct photoionization under reduced

Pressure conditions by Jetexpansion and / or carried out in a so-called "Ion Funnel". However, the applicability of the present invention is not limited to the application examples mentioned herein.

The wall of the light guiding device extending along the longitudinal direction may be non-conductive or partially conductive. The wall is thus for one

Variety of different applications individually customizable. Under the pressure reduction device

(Pressure reduction opening, pressure reduction stage) may be a Skimmereinrichtung, a diaphragm or a capillary

(Capillary opening) are understood. However, the design of the pressure reduction device is not limited to the examples listed here. Advantageous embodiments and further developments of the present invention are set out in the dependent claims and in the description of the figures.

In an advantageous embodiment, an inner atmosphere is adjustable within the light guide cavity, through which at least radiation of a vacuum ultraviolet partial spectral range can be conducted. By means of the advantageous Optical fiber device can thus also vacuum ultraviolet light over a distance through the ionization by the light guide device a desired

Ionisierungsort be supplied so that the unwanted absorption of vacuum ultraviolet light by (in the

Ionization chamber present) matrix molecules / matrix atoms is prevented. Thus, the present invention is also applicable to the use of vacuum ultraviolet light to ionize atoms and / or molecules.

For example, the optical waveguide device may additionally comprise a gas purging device, by means of which at least one ultraviolet-transmitting gas and / or at least one vacuum ultraviolet-transmitting gas through the

Lichtführungshohlräum are leitbar. Under the at least one ultraviolet transmitting gas and / or

Vacuum ultraviolet transmitting gas may be

Ultraviolet non-absorbing gas and / or a

Vacuum ultraviolet non-absorbing gas. The gas purging device can be designed, for example, to purging the Lichtführungshohlräum with nitrogen, hydrogen and / or a noble gas. Such a design of the gas purging device is inexpensive

executable.

Alternatively, the optical fiber device

additionally comprise a vacuum pump, by means of which an internal pressure below 50 mbar in the light guide cavity

is adjustable. In particular, by means of the vacuum pump, an internal pressure below 1 mbar in the Lichtführungshohlräum be adjustable. Also by means of an equipment of

Lightguide device with such a vacuum pump is an unwanted absorption of ultraviolet light,

in particular vacuum ultraviolet light, within the

Lichtführungshohlraums the light guide device

reliably preventable. The ion source side opening of the light guide cavity may preferably have a window or a lens. The window or the lens may in particular be at least partially made of a material that is transparent to the ionization radiation, such as LiF and / or MgF 2. In this way, a gas inlet from the ionization space in the light guide cavity can be reliably prevented.

In a further advantageous embodiment can

at least one electrode on the wall of the

Light guide device and / or in the

Lichtführungshohlräum be formed. In addition, the optical waveguide device may additionally have an electronic device, by means of which at least one potential at the at least one electrode and / or at least one

Alternating field between at least two of the electrodes can be applied. In this way, for example, a static electrical charge of the light pipe device

preventable. In an easily realizable embodiment, the light guide device can additionally a

electron beam pumped Excimer vacuum ultraviolet lamp (VUV lamp) whose emission from the

Light entry section is conductive to the light exit portion of the light guide device. The

Optical fiber device is not limited to an equipment with such a light source. By way of example, the optical waveguide device can also comprise a gas discharge lamp. Both described in this paragraph

Embodiments of an optical fiber device with a light source ensure one for ionizing

Atoms and / or molecules advantageously usable radiation in the vacuum ultraviolet spectral range. As an alternative or as a supplement to this, the

Fiber optic device also have a Nd: YAG laser.

In addition, the optical fiber device can additionally one Optics include by means of which a ninefold Nd: YAG laser radiation (by 118 μm) on the

Light entry section can be introduced into the light guide device, while a tripled radiation of the NdrYAG laser (around 355 nm) is filterable out. This also ensures a reliable ionization of atoms

and / or molecules.

Likewise, at the light exit section, a window or a lens comprising LiF and / or MgF2 may be formed. The light used for the ionization can thus transmit through the window or the lens, while an undesired intrusion of atoms / molecules from the ionization chamber into the light guide cavity is prevented.

In an advantageous development, the

Optical fiber device additionally comprise a cleaning device, by means of which at least one photolytic

Radical forming substance on a surface of the window or the lens can be applied. In this way, the window or lens can be reliably cleaned.

The advantages enumerated in the upper paragraphs are also with an ionizing device with such

Optical fiber device ensures.

In an advantageous embodiment of the

Be light emitting portion of the light guide device at a distance of less than 1 mm to an opening of the ionization device on the outside and / or the inside to be adjustable. Under the outside, a first side of the opening can be understood with a first pressure present there, while the inside a second side of the opening with a present there compared to the first pressure

reduced second pressure is. The opening may, in particular, be a skimmer opening, an aperture or a capillary

(Capillary opening). In this way, that can be done over the Optical guided ultraviolet light, in particular the guided vacuum ultraviolet light, are introduced directly to a favorable ionization site for ionizing the atoms and / or molecules.

The advantages described above also result in a spectrometer with such a light guide device or with a corresponding ionization device.

In addition, the advantages outlined above can also be realized by means of a corresponding method for ionizing atoms and / or molecules.

In an advantageous development, a method for detecting atoms and / or molecules on the

Method for ionizing atoms and / or molecules based. Also in this way, the advantages already mentioned above can be effected.

Hereinafter, exemplary embodiments of the

Invention with reference to the figures described in more detail. Show it :

Figure 1 is a schematic representation of a first

Embodiment of the light guide device;

Figure 2 is a schematic representation of a second

Embodiment of the light guide device;

Figure 3 is a schematic representation of a third

Embodiment of the light guide device;

Figure 4 is a schematic representation of a fourth

Embodiment of the light guide device;

and FIG. 5 is a flowchart for illustrating a

Embodiment of the method for ionizing atoms and / or molecules. Unless otherwise stated, the same apply

Reference numerals to corresponding elements of the

Characters .

Figure 1 shows a schematic representation of a first embodiment of the light guide device.

The schematically illustrated in Figure 1

Optical fiber device 10 includes a

Light guide device 12, which along a

Longitudinal direction 14 of a light entry section 16 of

Light guide device 12 extends to a light exit portion 18 of the light guide device 12. A width of the light guide 12 perpendicular to the longitudinal direction 14 increases from the light entrance portion to the

Light exit section 18 from. In the embodiment illustrated in FIG. 1, the light guiding device 12 can thus also be described as a light guiding finger and / or finger-shaped light guiding unit. It should be noted, however, that the light guide device 12 is not limited to a finger-shaped training.

The light guide device 12 has a wall 20

(Outer wall) on. The wall 20 may be at least partially

be designed conductive. For example, the wall 20 may be a gold or other metal coated

Include plastic wall scaffolding. However, the wall 20 may also be non-conductive. Within the wall 20, a light guide cavity 22 is formed, in which a

Inner atmosphere is adjustable, through which at least one radiation 24 of an ultraviolet partial spectral range

(This also radiation of a vacuum ultraviolet partial spectral range is understood) is conductive. As below more precisely, this ensures the advantageous usability of the optical fiber device 10 for ionizing atoms and / or molecules. The radiation 24 of the ultraviolet partial spectral range can be understood as meaning light with at least one wavelength between 1 nm and 380 nm, or with a frequency between 789 THz and 300 PHz. The radiation 24 of the ultraviolet partial spectral region may be a Gaussian

Have wavelength distribution. Likewise, the radiation 24 of the ultraviolet partial spectral range may have a

Have wavelength distribution with multiple maxima.

Preferably, an inner atmosphere is adjustable within the light guide cavity 22, through which at least radiation 24 of a vacuum ultraviolet partial spectral range can be conducted. The literature uses several spectral boundaries of vacuum ultraviolet light over ultraviolet light. It is noted here that the

Radiation 24 of the vacuum ultraviolet partial spectral range can be within the vacuum ultraviolet spectral range between 100 nm and 200 nm as well as in the extreme ultraviolet spectral range, also widely reported in the literature, of 1 nm to 100 nm. Frequently, the literature also specifies a spectral range from 5 nm to 180 nm for vacuum ultraviolet light. However, the radiation 24 of the vacuum ultraviolet partial spectral region, for which the internal atmosphere is set within the light guide cavity 22, may also be in only one

Spectral range from 1 nm to 100 nm or between 100 nm and 200 nm.

In the embodiment illustrated in FIG. 1, the optical waveguide device 10 comprises a (schematically reproduced) gas purging device 26, by means of which at least one

Ultraviolet transmitting gas and / or at least one vacuum ultraviolet transmittive gas through the Lichtführungshohlräum 22 are conductive. One can also rewrite this so that the Lichtführungshohlräum 22 by means of the gas purging device 26 with at least one

ultraviolet transmitting gas and / or a

Vacuumultravioletttransmittierenden gas is flushable.

For example, for purging the light guide cavity 22, nitrogen, hydrogen and / or a noble gas, such as

in particular helium can be used. You can enter

Such gas also as ultraviolet radiation-conducting gas, or as vacuum ultraviolet radiation-conducting gas

rewrite. By means of the flushing device formed on the light guiding device 12, a (virtually) loss-free conduction of the radiation 24 along the longitudinal direction 14 through the

Light guide device 12 effected. It should be noted, however, that the practicability of the

Optical fiber device 10 is not limited to an equipment with the gas purging device 26.

Optionally, the light guide device 10 may comprise a light source 28 which is designed to emit the radiation 24 of the ultraviolet partial spectral range, in particular the vacuum ultraviolet partial spectral range.

In addition, the optical waveguide device 10 may include at least one optical device 30 / at least one optical element

comprise, by means of which / which is emitted by the light source 28 radiation 24 at the light inlet portion 16 in the light guide device 12 is introduced, or the emission of the light source 28 from the light entry portion 16 to the light exit portion 18 of the light guide device 12 is conductive. The at least one optical device 30 may be, for example, a lens, a mirror, a beam splitter, a diaphragm and / or a filter. As the light source 28, for example, a laser can be used. Advantageously, the light source 28 is a pulsed Nd: YAG laser, in this case, by means of the at least one

Optical device 30 a ninefold radiation of the Nd: YAG laser to 118 nm at the light entry section 16 in the Light guide device 12 can be introduced, while a tripled radiation of the Nd: YAG laser can be filtered out by 355 rrm. However, instead of a Nd: YAG laser, another type of laser may be used as the light source 28. In addition, other embodiments of a non-laser suitable light source 28 will be described below.

The light guide device 10 can also be on its own

Dispel 28 light source. For example, too

different laser pulses external laser alternately or in any sequence in the light guide device 12 are coupled. The injectable laser pulses can have different wavelengths in the ultraviolet spectral range, in particular in the vacuum ultraviolet spectral range.

The optical fiber device 10 is designed for cooperation with an ionization device 32. This is the

Optical fiber device 10 in such a continuous

Opening 34 in a Ionisierungskammerwand 36 a

Ionization of the ionization device 32 can be arranged that at least a portion of the light guide device 12 protrudes into the ionization chamber. In addition, the

Light exit section 18 of the light guide device 12 in an operating position on a Skimmereinrichtung 38 of the ionization chamber adjustable.

It should be noted that the skimming device 38 represents only one example of a pressure reduction device, on which the light guide device 12 is adjustable. As an alternative to the skimming device 38, the pressure reduction device can also be designed, for example, as a diaphragm or capillary (capillary opening).

In particular, at the light guide device 10 or at the ionization device 32 a (not sketched) Adjusting device may be formed, by means of which the light exit section 18 of the optical waveguide device 10 at a distance of less than 1 mm to a Skimmeröffnung the

Skimmereinrichtung 38 / a skimmer of the ionization device 32 is adjustable. The adjustment of the light exit section can take place on an outer side and / or on an inner side of the skimming device 38. (Below the outside of the skimmer device 38, a side with a higher pressure compared to a lower pressure side can be understood.) Thus, the light exit section can be arranged / adjusted so close to an advantageous ionization site 40 that absorption the radiation 24 in an environment of the ionization site 40 is negligible. This can also be described in such a way that the radiation 24 can be brought (directly) to the preferred ionization location 40 by means of the optical waveguide device 10 and an adjustment that can be carried out, whereby path losses are negligible. In addition, in this way by means of the ultraviolet or

vacuum ultraviolet radiation 24 a trouble-free

Photoionization or light-induced chemical ionization of atoms and / or molecules on the preferred

Ionisierungsort executable with a comparatively high efficiency.

The applicability of the light guide device 10 is not limited to a particular design of the adjusting device

limited. For example, the adjusting device can be designed so that the light guide device 12 is pivotable. In particular, the distance between the skimmer device 38 and the light exit section 18 may be variably adjustable in at least two spatial directions. In an advantageous embodiment, a first pitch between the opening of the Skimmereinrichtung 38 and the

Light exit portion 18 along the longitudinal direction 14 to a value below an absorption path of the at

Light exit section 18 exiting light adjustable while a second pitch between the opening of the skimming means 38 and the light exit portion 18 perpendicular to the longitudinal direction 14 is adjustable to a value below a reaction path of the ionized atoms / molecules. Since the absorption path and the reaction path depend on various parameters, such as the

Wavelength of the light exit section 18

exiting light, the pressure in the ionization chamber and / or the atoms / molecules to be ionized, no figures are given here.

The with the light guide device 10th

cooperating / equipped ionization device 32 may include a vacuum pump 42, by means of which a negative pressure in an ionization chamber of the ionization device 32nd

adjustable. For example, within the

Ionization a pressure of 1 bar to 1 mbar by means of the vacuum pump 42 be adjustable. The Indian

Ionization chamber present pressure may also be less than 1 mbar. As an alternative to ionization in a

Underpressure by means of the optical fiber device 10, however, also an ionization at atmospheric pressure advantageously carried out. In particular, due to the advantageous introduction of the radiation 24 (almost) directly to the ionization site 40, path losses can be minimized despite an atmospheric pressure present at the ionization site.

It should be noted that (for example by means of a vacuum pump and / or the gas purging device 24) in the light guide cavity 22, an internal pressure may be adjustable, which corresponds to the pressure at the ionization 40. Alternatively, however, an internal pressure slightly above the pressure at the ionization site 40 may be adjustable in the light guide cavity 22, e.g. one

Gas entry from the ion source region in the

Lichtführungshohlräum 22 to prevent. Optionally, on or in the ionization chamber, a beam catcher 44 for absorbing the through the

Ionisierungsort 40 transmissive radiation 24 may be formed. However, the ionization chamber is also without the

Beam catcher 44 can be realized.

The light guide device 12 or the ionization device 32 equipped therewith may be a subunit of a

Be spectrometer 46. Preferably, the spectrometer 46 is designed for carrying out mass spectrometric analysis methods, as a result of which analytes 48 present in a liquid phase can be detected / determined. In Fig. 1 is the

Design for liquid samples by way of example only

shown. Alternatively, the inlet may be designed for gaseous samples. To carry out the analysis method, the analyte 48 dissolved in a solvent may first be passed through an LC capillary 50 with one attached thereto

Heaters 52 and a preferably formed with a nitrogen supply sprayer 54 are transferred into a solvent-analyte spray 56. The solvent analyte spray 56 is then added along a main spray direction 58 to the

Ionization 40 sprayed and ionized there. The analyte molecules are converted into ions. The ionized atoms and / or molecules can be aspirated by means of a skimmer device 38 and along a Hauptansaugrichtung 60, which may be the Hauptprührichtung 58, to a

Detector 62 are transferred. The detection device 62 may, for example, a mass spectrometer and / or a

Be ion mobility spectrometer. However, the feasibility of the detection device 62 is not limited to the spectrometers listed here.

Figure 2 shows a schematic representation of a second embodiment of the light guide device.

The schematically shown in Figure 2

Optical fiber device 10 and the cooperating Ionization device 32 already has some of the above

described components. A re-description of these components is therefore omitted here. As a supplement to the light exit section 18 a

Window 70 is formed, which comprises LiF and / or MgF2. Instead of or in addition to the ones mentioned here

Materials, the window 70 may also include at least one other material. Likewise, instead of the window 70, a lens may also be formed on the light exit section 18.

The window 70 or the correspondingly formed lens may also be referred to as an ultraviolet-transparent optical element or as a vacuum ultraviolet-transparent optical element. By means of such an optical element, in particular an undesired penetration of atoms or molecules from the ionization chamber in the

Lichtführungshohlraum 22 and / or an undesirable leakage of one of the gas purging device 26 through the

Lichtführungshohlraum 22 guided purge gas in the

Ionization chamber prevented / prevented.

As an alternative or in addition to the window 70 or the lens, the light guide device 12, or the

Lichtführungshohlraum 22, be mirrored inside. In this way, the light output can in particular at little

brilliant light sources can be improved. For example, when using vacuum ultraviolet light, the mirroring may consist of a (thin) layer of MgF 2 and / or LiF. The (thin) layer of MgF 2 and / or LiF may in particular be applied to aluminum.

In addition, the optical fiber device 10 may additionally comprise at least one cleaning device 72, by means of which at least one photolytic radical forming

Substance, such as chlorine, oxygen and / or water, on a surface of the mirror coating, the window 70 and / or the lens can be applied. The addition of the substance can

continuously or occasionally. In this way, the presence of the window 70 or lens is in an ultraviolet transmissive state and / or in one

vacuum ultraviolet-permeable state reliably

gewährleistbar. Likewise, it can be ensured that in particular the purified mirroring has its purpose with a

comparatively high efficiency.

In FIG. 2, a preferred position of the cleaning device 72 for cleaning the reflective coating of an inside of the

Light guide device 12, or the light guide cavity 22, shown. For cleaning the window 70 or the lens, the cleaning device 72 on the

Ion chamber side of the light guide device 12, which is contacted by the analyte molecules, and thus possibly contaminated, be arranged. FIG. 3 shows a schematic representation of a third embodiment of the optical waveguide device.

The reproduced schematically in Figure 3

Optical fiber device 10 has two complementary electrodes 80 formed in the Lichtführungshohlräum 22 as a supplement.

Instead of forming the electrodes 80 in the

Lichtführungshohlraum 22, at least one electrode may also be formed on the wall 20 of the light guide device 12. The optical waveguide device 10 additionally comprises an electronic device 81, by means of which at least one potential at the at least one electrode 80 and / or at least one alternating field between at least two of the

Electrode 80 can be applied. In this way, by means of the at least one electrode 80 and the electronic device 82, a static electrical charge of the

Light guide device 12 can be prevented. In an advantageous development, the at least two electrodes 80 and the electronic device 82 can also be used for a plasma discharge for the generation of ultraviolet radiation, in particular for the production of vacuum ultraviolet radiation. By means of the at least two electrodes 80 and the electronic device 82 is thus also a

Light source of the light guide device 10 can be realized.

Figure 4 shows a schematic representation of a fourth embodiment of the light guide device.

The reproduced schematically in Figure 4

Optical fiber device 10 has a cone-shaped light guide device 12. As the light source 28, the light guide device 10 has an ultraviolet-emitting

Lamp, preferably a vacuum ultraviolet-emitting lamp. In an advantageous embodiment, the

Optical fiber device 10 an electron beam pumped

Excimer vacuum ultraviolet lamp on. Instead of a

However, such light source 28, the light guide device 10 may also have a deuterium lamp, a gas discharge lamp and / or a laser.

The cooperating with the optical fiber device 10

Ionization device 32 is designed in this embodiment so that the main suction 60 along the

Longitudinal direction 14 extends. In contrast, the

Main spray direction 58 inclined to the main suction 60, preferably at an angle of 90 ° aligned. In this way, only the targeted by means of the radiation 24

recovered ions are transferred to the detection device 62, while non-ionized residues of the solvent-Anlytsprays 50 can be pumped off by means of the vacuum pump 42. It should be noted that the advantageous inclined orientation of the main suction direction 60 to the main spray direction 58 can also be implemented in the previously described embodiments. The above-described embodiments include the gas purging device 24 for adjusting the internal atmosphere transmissible to the radiation 24 in the

Light guide cavity 22 on. It is, however, on it

pointed out that the feasibility of

Optical fiber device 10 is not limited to an equipment with the gas purging device 24. Instead of

Gas purging device 24, for example, any of the embodiments described above, a vacuum pump

include, by means of which an internal pressure below 50 mbar in the light guide cavity 22 is adjustable. In particular, by means of the vacuum pump, an internal pressure below 1 mbar in the light guide cavity 22 may be adjustable. In one development, several can

Fiber optic devices 10 protrude into an ionization chamber. Each of the optical fiber devices 10 may have a different wavelength to the ionization site 40

emit. Thus, by means of the advantageous

Technology also ionization process with multiple and / or optionally different wavelengths are performed.

It is again pointed out that the

Optical fiber device 10 is useful in various methods for transferring analyte molecules into ions. The usability of the optical fiber device 10 is not limited to atmospheric pressure vacuum ultraviolet (ATI) ionization or ionization using ultra-violet pressure laser ionization (APLI).

FIG. 5 shows a flowchart for illustrating a

Embodiment of the method for ionizing atoms and / or molecules. The method described below can be implemented, for example, using the above-described embodiments of the optical waveguide device and / or the ionization device. However, the feasibility of the method is not based on the use of at least one of these

Devices limited.

In a method step Sl becomes

Light exit portion of a light guide means at a through opening in one

Ionisierungskammerwand an ionization chamber arranged light guide device in an operating position at a pressure reduction stage (pressure reduction device,

Pressure reduction opening) of the ionization chamber. The optical fiber device is so on the through

Opening arranged that at least a portion of the

Light guide device in the ionization chamber

protrudes. The pressure reduction stage can be, for example, a skimmer device, a diaphragm or a capillary. For the adjustment of the light exit section, an adjustment device arranged on the ionization chamber and / or the light guide device can be used. In addition, at least one air-tight seal between the

through opening and the arranged thereon

Fiber optic device are formed.

In a method step S2, an internal atmosphere is set in a light guide cavity formed within a wall of the light guide device. The

Inner atmosphere is adjusted so that at least radiation of an ultraviolet partial spectral range and / or a vacuum ultraviolet partial spectral range (almost

Absorbent) through the inner atmosphere is conductive. (Hereinafter, the ultraviolet partial spectral range will be so

understood that he also used the vacuum ultraviolet

Partial spectral range includes.) The inner atmosphere can be adjusted, for example, by a negative pressure, in particular a vacuum, in which Lichtführungshohlräum is applied by means of a vacuum pump. Also, for adjusting the inside atmosphere, the light guide cavity can be filled with an ultraviolet transmitting gas or with a

be flushed vacuum ultraviolet-transmitting gas.

Examples of usable gases are already above

indicated.

Furthermore, in a method step S3, atoms and / or molecules are ionized by means of the radiation of the ultraviolet partial spectral range guided by the light guide device. Preferably, the radiation is through such a light exit portion / a tip of

Guided light guide device that the radiation directly at the light exit section / the tip with the

ionizing atoms / molecules can interact and these photoionisiert. Since it is usually a

One photon ionization, which is e.g. At atmospheric or relatively high pressure, the ionization technique may also be referred to as APSPI (Atmospheric Pressure Single Photon

Ionization). With an APSPI ionization directly in front of a vacuum inlet, those in the

Atmospheric pressure or the relatively high pressure generated ions quickly drawn into the vacuum / vacuum area, so that only a few potentially reactive shocks occur.

Likewise, the ionization can be carried out in an ionization chamber in which (despite the use of a spray method) an internal pressure of less than 50 mbar,

especially less than 1 mbar, is present. The

However, photoionization can also take place at a relatively high pressure, wherein the contact number of the ions formed with the surrounding gas can be minimal, for example less than 100 ms, despite the high pressure due to an immediately following expansion. The photoionization can be carried out in one channel. For example, photoionization can occur directly in the

Expansion channel done. Likewise, the photoionization can be carried out in an ion Funnel, which the ions formed at a pressure between 1 to 10 mbar

electric fields leads. In addition, the photoionization can be operated directly before a critical or uncritical

Inlet opening (expansion nozzle, aperture, Skimmer) take place, which is the transition from a high pressure area in one

Low pressure range of a mass spectrometer represents.

In addition, the photoionization in a heated

Vacuum ion source, for example, for a

Electron ionization is designed to be performed. The preferably with a miniaturized spray unit

(Nanospray) equipped vacuum ion source can

if necessary be closed. The pressure in the

Vacuum ion source may be less than 0.1 mbar. It should be noted, however, that even at a higher pressure due to the use of the optical fiber device itself, a vacuum ultraviolet light can be reliably supplied to the ionization site. In addition, the ionization in one

controlled temperature regime above 100 ° C. Due to the advantageous use of

Optical fiber device and the alignment of the light exit section carried out in step S1, in carrying out each embodiment of step S3 described above, a trouble-free photoionization or light-induced chemical ionization of the atoms and / or molecules with ultraviolet or vacuum ultraviolet light ensured. The absorption of the ultraviolet or

Vacuum ultraviolet light due to undesired interaction with non-ionizable atoms / molecules is negligible. In an advantageous development, a plurality of optical fiber devices for ionizing the atoms and / or molecules can also be used. Also this training

makes it possible to bring ultraviolet or vacuum ultraviolet light directly to the preferred ionization site or

Ultraviolet or vacuum ultraviolet light near the ionization site.

The method described above may be part of a method for detecting atoms and / or molecules.

For example, for this purpose, the ionized atoms and / or molecules can be passed into a spectrometer after carrying out the method steps S1 to S3. Before ionizing, the atoms to be detected and / or molecules which may be dissolved in a solvent can be sprayed by means of a spray process such as, for example, a thermospray, a nanospray or a nanospray

Electrospray method to be evaporated from the liquid phase. In this case, the atoms and / or molecules to be detected are during ionization as

Gas phase molecules, clusters, particles or as sprayed droplets (analytes).

Claims

claims

Optical fiber device (10) for an ionization device (32) comprising: a light guide device (12) having a longitudinal direction (14) from a light entry portion (16) of the light guide means (12) to a

Light exit section (18) of the light guide device (12) extending wall (20), wherein within the wall (20) a Lichtführungshohlräum (22) is formed, in which an inner atmosphere is adjustable, through which at least radiation (24) of a

Ultraviolet partial spectral range and / or a

Vacuum ultraviolet partial spectral range is conductive; and wherein the optical waveguide device (10) can be arranged on a through opening (34) in an ionization chamber wall (36) of an ionization chamber such that at least a portion of the light guide device (12) projects into the ionization chamber and the light exit section (18) of the light guide device (12) in a

Operating position on a pressure reduction device (38) of the ionization chamber is adjustable.

2. optical fiber device (10) according to claim 1, wherein

within the light guide cavity (22) a

Inner atmosphere is adjustable, through which at least

Radiation (24) of a Vakuumultraviolett-Teilspektralbereichs is conductive.

3. optical fiber device (10) according to claim 1 or 2, wherein the optical fiber device (10) in addition to a

Gas purging device (26), by means of which at least one ultraviolet-transmitting gas and / or at least one vacuum ultraviolet transmissive gas through the

Light guide cavity (22) are conductive.

4. optical fiber device (10) according to claim 1 or 2, wherein the optical fiber device (10) additionally comprises a vacuum pump, by means of which an internal pressure below 50 mbar in the light guide cavity (22) is adjustable.

5. optical fiber device (10) according to claim 4, wherein means of the vacuum pump, an internal pressure below 1 mbar in the

Light guide cavity (22) is adjustable.

6. optical fiber device (10) according to any one of the preceding claims, wherein at least one electrode (80) on the wall (20) of the light guide device (12) and / or in the

Light guide cavity (22) is formed, and the

Optical fiber device (10) in addition to a

Electronic device (82) comprises, by means of which

at least one potential at the at least one electrode - (80) and / or at least one alternating field between at least two of the electrodes (80) can be applied.

7. Optical fiber device (10) according to one of the preceding claims, wherein the optical fiber device (10) additionally comprises an electron beam pumped Excimer Vakuumultraviolett-

Lamp whose emission from the light entry portion (16) to the light exit portion (18) of the

Light guide device (12) is conductive.

8. The optical waveguide device according to claim 1, wherein the optical waveguide device comprises an Nd: YAG laser, and wherein the optical waveguide device additionally comprises an optical device by means of which X-fold radiation of the Nd: YAG laser around 118 nm at the light entry section (16) in the

Light guide device (12) can be introduced while a tripled radiation of the Nd: YAG laser can be filtered out by 355 nm.

9. optical fiber device (10) according to any one of the preceding claims, wherein at the light exit portion (18) a

Window (70) or a lens comprising LiF and / or MgF2 is formed.

10. optical fiber device (10) according to claim 9, wherein the optical fiber device (10) in addition to a

Cleaning device (72), by means of which

at least one photolytic radical-forming substance can be applied to a surface of the window (70) or the lens.

11. Ionization device (32) with an optical waveguide device (10) according to one of the preceding claims.

12. Ionization device (32) according to claim 11, wherein the

Light exit portion (18) of the light guide device (10) at a distance of less than 1 mm to an opening of the

Ionizing device (32) on the outside and / or the inside of which is adjustable.

13. spectrometer (46, 62) with a light guide device (10) according to one of claims 1 to 10 and / or with a

Ionization device (32) according to claim 11 or 12.

14. A method of ionizing atoms and / or molecules comprising the steps of:

Adjusting a light exit section (18) of a

Light guide device (12) one at a through opening (34) in a Ionisierungskammerwand (36) of a

Ionization chamber arranged light guide device (10), wherein at least a portion of the light guide means (12) protrudes into the ionization chamber, in a Operating position at a pressure reduction stage (38) of the ionization chamber (Sl);

Adjusting an interior atmosphere through which at least radiation (24) of an ultraviolet partial spectral region and / or a vacuum powder partial spectral region is conductible, in one within a wall (20) of

Light guide device (12) formed

Lichtführungshohlräum (22) (S2); and

Ionizing atoms and / or molecules by means of the radiation (24) of the ultraviolet partial spectral range and / or the light guided by the light guiding device (12)

Vacuum ultraviolet partial spectral region (S3).

15. A method of detecting atoms and / or molecules comprising the steps of:

Ionizing the atoms and / or molecules according to the method of claim 14; and

Introducing the ionized atoms and / or molecules into

Spectrometer (62).