A device for inserting a sample carrier rotor into an NMR probe

Abstract

The present invention relates to a device for inserting a sample (E) into a sealed enclosure (1), the device comprising: a sample carrier (10) for holding a sample; an insertion rod (7) with an elongated portion (8) suitable for carrying a sample carrier (10); an exterior door (20) intended to be closed in a watertight manner and to open into the environment (M) outside the sealed enclosure; an internal door (21) intended to be closed in a watertight manner and to open inside the sealed enclosure; a sealed chamber (19) defined between the outer door and the inner door when in a sealed configuration, the sealed chamber (19) configured to accommodate a sample carrier inserted by an insertion rod; and a transfer airlock (14) comprising a fluid medium contained therein, a sample carrier housed in a sealed chamber and a system for sample purification; Equipped with.

Description

[Technical Field]

[0001] The present invention relates to a device for transferring an object from one fluid environment to another, the two environments having different fluids and / or temperatures and / or pressures.

[0002] Although the present invention is described for the application of nuclear magnetic resonance (NMR) spectroscopy, the present invention can be implemented in any other application requiring sealed transfer of an object from one fluid environment to another, more particularly in an environment having controlled pressure and / or humidity and / or particle contamination and / or radiation levels. [Background technology]

[0003] Nuclear magnetic resonance (NMR) spectroscopy is a non-destructive analytical method that uses the phenomenon of nuclear magnetic resonance (NMR), particularly to resolve molecular structure. NMR is performed when atomic nuclei with non-zero spin are placed in a static magnetic field and excited by electromagnetic radiation. This method is used, among other things, in organic chemistry, inorganic chemistry, biology, and materials science.

[0004] In solid state NMR spectroscopy, the sample to be analyzed is conventionally placed in a rotor to rotate the sample around an axis tilted by 54° 44′, known as the magic angle, relative to the static magnetic field.

[0005] It is also known that increasing the strength of the magnetic field, increasing the frequency of rotation of the rotor and / or using the phenomenon of dynamic nuclear polarization (DNP) makes it possible to improve the sensitivity and resolution of NMR spectroscopy.

[0006] It has been proven that the lower the temperature during NMR analysis, the greater the signal-to-noise ratio and the greater the gain caused by the DNP phenomenon. Therefore, high-resolution NMR spectrometers generally operate at low temperatures, in particular around 100 K. In the article "Non-Patent Document 1," an NMR spectrometer using the DNP phenomenon and operating at temperatures below 100 K is described.

[0007] To achieve low temperatures, for example, below about 100 K, the NMR spectrometer preferably operates autonomously in a closed loop. An autonomously operating device is one that does not require a cryogenic fluid supply. A closed loop device is one in which the working fluid circulates without exposure to the external environment and without the fluid reaching outside the loop.

[0008] In this type of closed-loop autonomous device, it is important to maintain a very pure working fluid, i.e., the working fluid should be as free as possible from impurities, regardless of its nature (gas, solid in particulate form, derived from hydrocarbons, etc.).

[0009] In an NMR spectrometer, contamination of the working fluid can be caused by placing the sample to be analyzed in a fixed position within the NMR probe.

[0010] 1A to 1E illustrate the various steps of placing a sample in position in the probe 1 of an NMR spectrometer according to the prior art.

[0011] The probe 1 comprises a base wall 2 , a cover 3 and a stator 4 .

[0012] To be able to open the probe 1, it is first necessary to heat the internal environment 5 defined by the base wall 2 and the cover 3 assembled together in a sealed manner (FIG. 1A).

[0013] The probe 1 is then manually opened by lifting the sealing cover 3 (FIG. 1B).

[0014] Next, the rotor 6, which contains the sample to be analyzed, is manually placed into position within the stator 4 (FIG. 1C).

[0015] The cover 3 is then put back into place in a sealing manner once again to close the probe 1 (FIG. 1D).

[0016] The internal environment 5 is then cooled and then a series of purification cycles of the working fluid are applied to remove impurities introduced during the period when the probe 1 was opened and the rotor 6 was inserted into the stator 4 (Figure 1E).

[0017] The total duration of the described steps, which involves placing the sample in place in the probe 1, is about 8 hours, which is particularly time-consuming. In addition, the cleaning cycle is complicated to perform. [Prior art documents] [Non-patent literature]

[0018] [Non-Patent Document 1] Yoh Matsuki, Toshimichi Fujiwara, "Cryogenic Platforms and Optimized DNP sensitivity", eMagRes, 2018, Vol 7: 9~24 Summary of the Invention [Problem to be solved by the invention]

[0019] Therefore, there is a need for a solution that makes it possible to reduce the period during which the sample to be analyzed is placed in position in the NMR probe and to simplify the implementation of existing processes.

[0020] More generally, there is a need for a solution that allows for simple and rapid transfer of a sample from an external environment to a controlled environment, while limiting the introduction of impurities into the controlled environment.

[0021] It is an object of the present invention to at least partially satisfy this need. [Means for solving the problem]

[0022] To this end, the present invention relates to a device for inserting a sample into a sealed enclosure, said device comprising: a sample carrier for carrying the sample; an insertion rod with an elongated portion, the end of which is designed to carry a sample carrier; - a transfer airlock, * an exterior door that is closed in a sealed manner and is designed to open to the environment outside the sealed enclosure; * an internal door that is closed in a sealed manner and is designed to open directly or indirectly into the interior of the sealed enclosure by means of at least one sealed duct; a sealed chamber defined between an outer door and an inner door, the sealed chamber being configured to accommodate a sample carrier inserted by an insertion rod when the outer door and the inner door are in a sealed closed configuration; a transfer airlock comprising: - A system for purifying a sample carrier and a sample housed in a contained fluid environment and a sealed chamber Equipped with.

[0023] The purification system according to the invention serves the purpose of reducing the level of impurities and / or radioactivity in the fluid environment contained in the sealed chamber and therefore in the sample carrier and the sample to be analyzed that it carries.

[0024] By "level of impurities in a fluid environment" is meant in this specification and in the context of the present invention the ratio, generally expressed in ppm (parts per million), of the mass fraction of the impurity contained in the fluid environment to the total mass of said fluid environment.

[0025] Radioactive elements and / or impurities are any gaseous, liquid, or solid element in particulate form that is undesirable in the intended fluid environment, i.e., does not correspond to the level of fluid purity and / or level of radioactivity required to fill the sealed enclosure. For example, the level of impurities may be 100 ppm or less.

[0026] Preferably, the exterior door comprises a gland configured to be compressed in a sealing manner by the elongated portion of the insertion rod while leaving the insertion rod translatable.

[0027] Preferably, the purification system comprises: a discharge valve configured to discharge the fluid contained in the chamber down to a nominal pressure, known as the underpressure; - a fill valve configured to fill the chamber with a predefined fluid, which is intended to fill the sealed enclosure up to another rated pressure known as high pressure; Equipped with.

[0028] Preferably, the low pressure is below 10 mbar and / or the high pressure is above 1 bar, or 1.1 bar, preferably between 1 bar and 3 bar.

[0029] Preferably, the fill valve is configured to passively close when the pressure in the chamber reaches a high pressure.

[0030] Preferably, the predefined fluid is a pure gas, preferably helium, which is at least 99.999% pure.

[0031] Preferably, the elongated portion extends along a length of between 15 cm and 30 cm. Preferably, the elongated portion has a cylindrical shape, preferably with a diameter of between 0.3 cm and 1.0 cm.

[0032] Preferably, the end of the elongated portion opposite that carrying the sample carrier is provided with a gripping handle. Preferably, the gripping handle has a diameter larger than the diameter of the opening in the exterior door, for example by 10 mm or more.

[0033] Preferably, the sample carrier comprises a cavity into which the sample is intended to be inserted. Preferably, the cavity has a cylindrical shape, preferably with a diameter between 0.8 mm and 3.3 mm and / or a height between 12 mm and 20 mm, for example 18 mm.

[0034] Preferably, the sample carrier comprises a slot that opens into the cavity and is configured to allow injection of a fluid into the cavity so as to force the sample out of the cavity.

[0035] Preferably, the internal door is a sliding valve configured to slide between a closed position in which the internal door is closed in a sealed manner and an open position in which the internal door is open to allow passage of the sample carrier and the elongated portion of the insertion rod.

[0036] Preferably, the interior door is 1.10 -5 The seal is configured to maintain its closure at a pressure of 0.1 mbar or less.

[0037] Preferably, the gland comprises at least one, preferably at least two, sealing portions, a clamping ring and a screw, and is configured such that when the screw is screwed, the clamping ring compresses the sealing portion, which in turn compresses the elongated portion, thereby ensuring sealing of the exterior door closure.

[0038] Preferably, the screw is hollow and has an inner diameter that is larger than the diameter of the sample carrier and the elongated portion.

[0039] Preferably, the gland comprises an annular chamber in which the seal is partially housed, the annular chamber having a diameter of 1.10 mm. -3 The pressure is below mbar.

[0040] Preferably, the chamber is 3000 mm 3 and 7000mm 3 It has a volume between

[0041] Preferably, the chamber has a tubular shape with an inner door at one end of the tube and an outer door at the other end of the tube.

[0042] Preferably, the distance between the outer door and the inner door is between 0 cm and 20 cm.

[0043] The invention also relates to a system comprising a sealed enclosure and a device according to the invention, wherein the outer door of the transfer airlock is designed to open to the environment outside the sealed enclosure and the inner door of the transfer airlock is designed to open into the interior of the sealed enclosure, directly or indirectly, via a sealed duct.

[0044] Preferably, the system is a nuclear magnetic resonance (NMR) spectrometer and the sealed enclosure is a probe configured to excite atomic nuclei of a sample. Preferably, the probe is configured to perform a dynamic nuclear polarisation phenomenon.

[0045] Preferably, the internal environment of the probe consists of a fluid in which the sample is intended to be immersed, and the probe is configured to maintain said fluid at a temperature below 100 K, and preferably said fluid is helium that is at least 99.999% pure.

[0046] Preferably, the system comprises a rotor on which a sample is intended to be mounted and configured to be carried by a sample carrier, and the probe comprises a stator configured to rotate the rotor.

[0047] Preferably, the probe comprises an air tube connecting the transfer airlock to the stator and configured to displace the rotor of the sample carrier by propulsion to the stator when inserted into the probe, or vice versa.

[0048] The present invention also relates to a method for the operation of a system according to the invention, comprising the following steps: a) placing a sample in position on a sample carrier of an insertion rod; b) inserting the sample carrier and sample into the chamber of the transfer airlock through an outer door, the inner door being closed in a sealing manner; c) clamping the gland to compress the strip so as to sealably close the exterior door; d) purifying the fluid contained in the chamber by a purification system; e) opening the inner door and inserting the sample carrier and sample into the sealed enclosure through the inner door, the gland remaining clamped to compress around the elongated portion to maintain the outer door sealed closed; The present invention relates to a method comprising:

[0049] According to the present invention, "purifying" a fluid means reducing its level of impurities.

[0050] Preferably, the purification system of the device comprises: a discharge valve configured to discharge the fluid contained in the chamber down to a nominal pressure, known as the underpressure; - a fill valve configured to fill the chamber with a predefined fluid, which is intended to fill the sealed enclosure up to another rated pressure known as high pressure; Equipped with Step d) comprises the following sub-steps: d1) opening the exhaust valve to exhaust the fluid, e.g., gas, contained in the chamber down to a nominal pressure, known as the underpressure, while the fill valve is closed; d2) closing the discharge valve; d3) opening a fill valve to fill the chamber with a fluid that constitutes the internal environment of the sealed enclosure, for example, helium that is at least 99.999% pure, to another rated pressure, known as high pressure; d4) closing the filling valve; It includes at least one repetition of

[0051] Preferably, the low pressure is below 10 mbar and / or the high pressure is between 1 bar and 3 bar.

[0052] Preferably, step d) comprises at least three repetitions of sub-steps d1) to d4).

[0053] Preferably, the system is a nuclear magnetic resonance (NMR) spectrometer, the sealed enclosure is a probe configured to excite atomic nuclei of the sample, and the method includes, after step e), step g) of performing nuclear magnetic resonance spectroscopy of the sample.

[0054] Preferably, the probe of the system comprises a pneumatic tube connecting the transfer airlock to the stator and is configured to displace the rotor of the sample carrier by propulsion when inserted into the probe to the stator, and vice versa, and step g) is preceded by step f) of placing the rotor, on which the sample is mounted, in position in the stator by propulsion of said rotor in the pneumatic tube.

[0055] Preferably, the method comprises a subsequent step h) during which the sample is removed from the sealed enclosure, said step h) comprising the following sub-steps: h1) withdrawing the insertion rod to place the sample carrier and sample in position in the chamber of the transfer airlock, the gland remaining clamped to compress the elongated portion so as to keep the sample carried by the sample carrier and the outer door sealed closed; h2) sealing and closing the interior door; h3) optionally opening the fill valve; h4) opening the gland to open the exterior door sufficiently to allow the sample carrier and sample to pass through; h5) Removing the sample carrier and sample from the transfer airlock through the exterior door; h6) optionally placing the sample carrier back into position in the chamber of the transfer airlock, the sample being removed from the sample carrier, then closing the fill valve, if applicable, and clamping the gland to compress the strip so as to sealably close the exterior door; Includes.

[0056] Thus, the present invention essentially consists of a device comprising a transfer airlock and an insertion rod with a sample carrier for easily inserting a biological sample or material sample to be analyzed into a sealed enclosure such as an NMR probe.

[0057] When a sample carrier carrying a sample is housed in a chamber of the transfer airlock defined by two doors that are closed in a sealed manner, a purification system can purify impurities introduced into the chamber by the sample carrier inserted into the chamber.

[0058] Once the impurity levels and / or radioactivity levels of the fluid environment contained in the chamber have reached a sufficiently low level for the sealed enclosure, the inner door of the airlock can be opened and the sample carrier with the sample can be inserted by the rod into the sealed enclosure without contaminating it.

[0059] Handling for insertion of a sample into the sealed enclosure is simple, a simple translation of the insertion rod is sufficient. According to an advantageous embodiment, the elongated portion of the rod is compressed by the gland while it remains translatable, which ensures that the exterior door is sealed closed throughout the entire translation process of the insertion rod.

[0060] The present invention advantageously allows the transfer of a sample from an external fluid environment to a fluid environment contained in a sealed enclosure, the transfer being simple and rapid to perform while limiting the introduction of impurities into the fluid environment of the sealed enclosure. In particular, the sample can be transferred in a few minutes. For example, in an NMR spectrometer, the step of placing the rotor, to which the sample is attached, in the stator of the probe of the NMR spectrometer can be performed in 5 minutes thanks to the present invention, compared to 8 hours in an NMR spectrometer according to the prior art.

[0061] Additionally, the purification system may be configured to set the fluid environment contained in the sealed chamber to a given pressure, which advantageously allows the insertion of a sample into the sealed enclosure to have no or very little effect on the pressure of the fluid environment of the sealed enclosure.

[0062] Other advantages and characteristics will become more apparent on reading the detailed description given by way of non-limiting example and with reference to the following drawings, in which: [Brief explanation of the drawings]

[0063] [Figure 1A] 1 is a schematic view of a probe according to the prior art with the probe cover closed; [Figure 1B] 1B is a schematic view of the probe according to FIG. 1A with the probe cover open; [Figure 1C] 1B is a schematic diagram of a probe according to FIG. 1A, with the cover of the probe open and the rotor with the sample mounted thereon being placed in the stator of the probe. [Figure 1D] 1B is a schematic diagram of a probe according to FIG. 1A, with the cover of the probe closed and the rotor with the sample mounted thereon placed in the stator of the probe. [Figure 1E] 1B is a schematic diagram of a probe according to FIG. 1A, with the cover of the probe closed and the rotor with the sample mounted thereon placed in the stator of the probe. [Figure 2A]FIG. 1 shows a side view of the insertion rod of a device according to the invention, without the rotor with the sample mounted thereon inserted into the insertion rod. [Figure 2B] FIG. 2 shows a side view of the insertion rod of the device according to the invention, in which the rotor with the sample mounted thereon is inserted. [Figure 3] 1 is a schematic longitudinal cross-sectional view of a portion of an NMR spectrometer with an airlock for the transfer of a device according to the invention, connected to a probe for NMR spectroscopy; [Figure 4] 1 is a schematic longitudinal cross-sectional view of a portion of an NMR spectrometer comprising a device according to the invention, a transfer airlock of the device connected to a probe for NMR spectroscopy, and an insertion rod of the device partially inserted into the transfer airlock, with a sample carrier housed in the chamber of the airlock; [Figure 5] 1 is a schematic longitudinal cross-sectional view of an NMR spectrometer comprising a device according to the invention, a transfer airlock of the device connected to a probe for NMR spectroscopy, and a sample carrier of an insertion rod of the device inserted into the probe. [Figure 6] 1 is a schematic longitudinal cross-sectional view of a portion of an NMR spectrometer comprising a device according to the invention, a transfer airlock of the device connected to a probe for NMR spectroscopy, a sample carrier of the insertion rod of the device inserted into the probe, and a rotor extruded from the sample carrier. [Figure 7A] FIG. 1 is a schematic diagram of a probe of an NMR spectrometer connected to an airlock for the transfer of a device according to the invention, the probe comprising an air tube through which the rotor is propelled towards the stator of the probe. [Figure 7B] FIG. 7B is a schematic diagram of the probe and transfer airlock according to FIG. 7A, with the rotor inserted into the stator of the probe. DETAILED DESCRIPTION OF THE INVENTION

[0064] For the sake of clarity, the various elements of the drawings are drawn to scale and the true dimensions of the various parts are not necessarily adhered to.

[0065] 1A to 1E have already been mentioned in the preamble and will not be mentioned further below.

[0066] FIG. 2A illustrates a portion of an insertion rod 7 of a device according to the invention, the end of which carries a rotor 6 intended to contain a sample E to be analyzed.

[0067] The insertion rod 7 comprises an elongated portion 8 extending along a longitudinal axis X, one of whose longitudinal ends is in the form of a gripping handle 9 and the other of whose longitudinal ends can carry a sample carrier 10. The elongated portion 8 may be cylindrical with a length of 180 mm and a diameter of 6 mm. The handle 9 may, for example, be cylindrical with a length of 20 mm and may be provided with a groove to facilitate gripping of the insertion rod 7.

[0068] The sample carrier 10 comprises a cavity 11 for receiving and supporting the rotor 6, and a slot 12 opening into the cavity 11 between the longitudinal ends of the elongated portion 8 and the cavity 11. The cavity 11 has a cylindrical shape with a diameter between 0.8 mm and 3.3 mm, for example equal to 3.3 mm, and / or a height between 12 mm and 20 mm, for example equal to 18 mm. These dimensions are suitable for cryogenic NMR spectroscopy. The cavity 11 can thus have a shape complementary to that of the rotor 6, which is, for example, cylindrical with a diameter between 0.7 mm and 3.2 mm, for example equal to 3.2 mm, and / or a height between 12 mm and 20 mm, for example equal to 17 mm.

[0069] The end of the elongate portion 8 and / or the sample carrier 10 may support an O-ring seal 13 around its periphery.

[0070] In FIG. 2B, the rotor 6 is housed in a cavity 11 .

[0071] FIG. 3 illustrates an NMR spectrometer with an airlock 14 for the transport of a device according to the invention assembled with a probe 1 for NMR spectroscopy by means of a sealed duct 15 .

[0072] The probe 1 is a sealed enclosure with a sealed wall 2, the internal environment 5 of which consists of helium that is at least 99.999% pure.

[0073] 1 to 1D in that it comprises an air tube 16 arranged in a sealed housing and a connection 17 opening into the interior of the air tube 16 so that gas, preferably helium with a purity of at least 99.999%, can be injected into the air tube 16. A passage 18 connects the sealed duct 15 to the air tube 16 in a sealed manner.

[0074] When in a sealed closed configuration, transfer airlock 14 comprises a chamber 19 defined by an outer door 20 and an inner door 21. The outer door is openable to the environment M outside the sealed enclosure, and the inner door 21 is openable to the sealed duct 15. The distance between outer door 20 and inner door 21 is less than the length of elongated portion 8.

[0075] In the example described, the chamber 19 preferably has a hollow cylindrical shape with a diameter of 45 mm or less.

[0076] The inner door 21 is a sliding valve that can be closed in a sealing manner and can be opened sufficiently to allow the passage of the sample carrier 10 and elongated portion 8 .

[0077] The exterior door 20 includes a gland 25 configured to compress the elongated portion 8 in a sealing manner while leaving the insertion rod 7 translatable for insertion into the transfer airlock 14.

[0078] The gland 25 comprises two clamp rings 26, two seals 27, and a hollow screw 28. The inner diameter of the hollow screw 28, which is smaller than the diameter of the handle 9, is sufficient to allow the passage of the sample carrier 10 with the sample E and the elongated portion 8. When the hollow screw 28 is tightened, it compresses the clamp ring 26 against the seal 27, which in turn compresses. The compression of the seal 27 reduces its inner diameter, which may therefore be smaller than the outer diameter of the elongated portion 8. In this way, the seal 27, which is compressed while surrounding the elongated portion 8, is compressed around the elongated portion 8, thereby achieving a sealed closure of the exterior door 20.

[0079] The gland 25 also includes an annular chamber 29 around the clamp ring 26 and the seal 27. The annular chamber 29 is filled with a vacuum, typically 1.10 -3 The pressure is then pumped to a pressure of 1.10 mbar or less. Thus, the volume between the clamp ring 26 and the sealing portion 27 and the volume between the two sealing portions 27 are increased to 1.10 mbar or less. -3 This results in a pressure of less than mbar, which makes it possible to ensure a better compression of the seal and a better sealing of the exterior door closure.

[0080] The exterior door 20 also includes a clamp flange 30 that compresses a seal 31 to ensure a seal between the gland 25 and the interior of the chamber 19 .

[0081] The chamber 19 is configured to receive a sample carrier 10 having an elongated portion 8 compressed by a gland 25, such that the chamber 19 is closed in a sealed manner. The chamber 19 is also configured such that the sample carrier 10 passes through the chamber 19 through an outer door 20 and an inner door 21.

[0082] The transfer airlock 14 also includes a drain valve 23 configured to drain the fluid contained in the chamber 19, and a fill valve 24 configured to fill the chamber 19 with helium that is at least 99.999% pure. Thus, the purge fluid may be the same fluid as that of the internal environment 5.

[0083] A method for the insertion of a sample E into a probe 1 with a device according to the invention will now be described.

[0084] First, the method comprises step a) of placing the sample E in position on the insertion rod 7. During this step a), the sample E is mounted in the rotor 6, which is then inserted into the cavity 11 of the sample carrier 10, as illustrated in FIG.

[0085] The method then comprises step b) of inserting the rotor 6 and the sample carrier 10 into the chamber 19. During this step b), the inner door 21 is sealingly closed, and the valves 23 and 24 are also sealingly closed. The insertion is carried out by translation of the insertion rod 7 through the outer door 20, without clamping the gland 25. After insertion, the gland 25 is positioned without compression around the elongated portion 8, and the rotor 6 and the sample carrier 10 are entirely housed within the chamber 19 (FIG. 4).

[0086] Step b) is followed by step c), during which the gland 25 is clamped in compression around the elongated portion 8, thus sealingly closing the outer door 20. The chamber 19 is then hermetically closed with the rotor 6 and sample carrier 10 housed therein.

[0087] Step d) then carries out the purification of the fluid contained in chamber 19. This step d) comprises the following sub-steps: d1) opening the exhaust valve 23 to exhaust the fluid, e.g., gas, contained in the chamber to a nominal pressure, known as the underpressure, while the fill valve 24 is closed; d2) closing the discharge valve 23; d3) opening the fill valve 24 to fill the chamber 19 with the fluid that constitutes the internal environment 5 of the probe 1 up to another rated pressure, known as high pressure; d4) closing the filling valve 24, which can be performed passively when the pressure inside the chamber 19 reaches a high pressure; It includes at least one repetition of

[0088] This purification step d) makes it possible to eliminate, by dilution, the impurities introduced during the insertion of the rotor 6 and the sample carrier 10 into the chamber 19. In particular, during step b), the chamber 19 is filled with the atmosphere of the external environment M. Step d) then makes it possible to dilute the contaminating gases with the fluid constituting the internal environment 5 sufficiently so that, after purification, the level of impurities contained in the chamber 19 is less than 0.00001%, which corresponds to 100 ppm.

[0089] Step d) may comprise at least three repetitions of substeps d1) to d4). The ratio between the volume of the chamber 19 and the volume of the sealed enclosure 1 may be 1 / 100,000 or less. This advantageously makes it possible to improve the dilution of contamination with each repetition of substeps d1) to d4) and, consequently, to increase the rate at which the level of impurities in the fluid environment of the chamber 19 decreases. The level of dilution of impurities with each repetition of substeps d1) to d4), i.e., the ratio between the level of impurities after a repetition and the level of impurities before said repetition, may in particular be 1% or less, or 0.9% or less.

[0090] Step d) is followed by step e), during which the inner door 21 opens and the insertion rod 7 slides along its elongated portion 8 to insert the rotor 6 and sample carrier 10 into the air tube 16. The gland 25 remains clamped throughout step e) to maintain the outer door 20 sealed closed. The clamping during step e) may be lower than during step d) to facilitate translation of the insertion rod 7. Specifically, during step d), the clamping of the gland 25 may be such that any translation of the insertion rod 7 is blocked by the clamp, thus maintaining the rotor 6 and sample carrier 10 in a fixed position in the chamber 19. During step e), the gland 25 may be slightly opened to allow translation of the insertion rod 7 along the longitudinal axis X while the outer door 20 remains sealed closed.

[0091] 5 illustrates an NMR spectrometer with rotor 6 and sample carrier 10 inserted into air tube 16 of probe 1 by means of the rod of a device according to the invention. In this configuration, handle 9 abuts external door 20. O-ring seal 13 is housed in passage 18 to ensure sealing between duct 15 to be sealed and air tube 16. Slot 12 is aligned with connection 17.

[0092] Step e) is followed by step f) of placing the rotor 6, on which the sample E is attached, in position in the stator 4 of the probe 1. In particular, step f) is carried out by the propulsion of the rotor 6 in the air tube 16. As illustrated in Figure 6, a fluid F, preferably helium with a purity of within 99.999%, circulates in the connection 17 by means of the slot 12 as far as into the cavity 11. Under the propulsion of the fluid F, the rotor 6 is pushed out of the cavity 11 and guided along the air tube 16.

[0093] During the navigation through the air tube 16 and the NMR probe, the insertion rod 7 remains inserted into the transfer airlock 14 with the outer door 20 sealed closed.

[0094] FIG. 7A illustrates the guidance of the rotor 6 along the air tube 16 under impetus by the fluid F to the stator 4 of the probe 1 .

[0095] 7B illustrates the rotor 6 being introduced into the stator 4 of the probe 1. During step g), the sample E is then observed by NMR spectroscopy. During step g), the rotor 6 rotates the sample E in the stator 4 around an axis tilted at 54° with respect to the magnetic field for NMR spectroscopy. The rotation speed of the sample E may be greater than one million revolutions per minute. The stator 4 may comprise an aerostatic bearing supplied with helium of at least 99.999% purity to guide the rotating rotor 6. The sample E may be rotated by a flow of helium of at least 99.999% purity.

[0096] Preferably, during step g), the internal environment 5 of the probe 1 is at a pressure between 1 bar and 3 bar and / or at a temperature below 100 K. In particular, the probe 1 can operate autonomously in a closed loop, for example, it can be equipped with a heat exchanger and at least one cold source, for example a refrigerator / freezer. The internal environment 5 is made of helium with a purity of at least 99.999%, which facilitates controlling the internal environment 5 at the above-mentioned pressure and temperature. The stator 4 can be supplied with helium with a purity of at least 99.999% and a temperature below 100 K, and this flow of cold helium makes it possible to maintain the sample E at a temperature below 100 K.

[0097] After NMR spectroscopy, during step h), rotor 6 and sample E can be removed from probe 1. To this end, step h) comprises sub-step h1), during which rotor 6, on which sample E is mounted, is pushed out of stator 4 and guided along pneumatic tube 16 until rotor 6 is inserted into cavity 11 of sample carrier 10. Insertion rod 7 is then pulled to place sample carrier 10 and sample E in position in chamber 19 of transfer airlock 14, while outer door 20 remains closed in a sealing manner by elongated portion 8 and gland 25.

[0098] Substep h1) is followed by substep h2), during which the inner door 21 is sealed and closed, and substep h2) is followed by substep h3), which opens the fill valve 24 and then fills the chamber 19 with helium of at least 99.999% purity.

[0099] Next, during substep h4), the gland 25 is opened so that the exterior door 20 allows the passage of the sample carrier 10 and the sample E. Then, during substep h5), the insertion rod 7 is pulled outward in order to remove the sample carrier 10 and the sample E from the transfer airlock 14 through the exterior door 20.

[0100] Step h) comprises a further sub-step h6), during which the sample E is removed from the cavity of the sample carrier 10, which is then returned to its original position in the chamber 19 without the sample E. The gland 25 is then clamped to compress the elongated portion 8 and sealably close the outer door 20. The filling valve 24 is then sealed.

[0101] Other variations and improvements can be devised without departing from the scope of the invention as defined by the appended claims.

[0102] Although application to NMR spectroscopy is specifically described, the invention can be applied to any system requiring the transfer of an object from one fluid environment to another, particularly a controlled environment. [Explanation of symbols]

[0103] 1 probe 2 Basic walls 3 Cover 4 Stator 5 Internal environment 6 rotors 7 Insertion Rod 8. Long, thin section 9 Grasping Handle 10 sample carriers 11 Cavity 12 slots 13 O-ring seal 14 Transfer Airlock 15 Sealed ducts 16 Air Tube 17 Connection 18 aisles 19 Chamber 20 Exterior Door 21 Interior Door 23 Discharge valve 24 Filling valve 25 grand 26 Clamp ring 27 Sealing part 28 Hollow screw 29 Annular Chamber 30 Clamp flange 31 Sealing part

Claims

1. A device for inserting a sample (E) into a sealed enclosure (1), comprising: a sample carrier (10) for carrying said sample; an insertion rod (7) with an elongated portion (8), the end of which is designed to carry said sample carrier (10); an exterior door (20) that is closed in a sealing manner and is designed to open to the environment (M) outside said sealed enclosure; an internal door (21) that is closed in a sealed manner and is designed to open directly or indirectly into the interior of said sealed enclosure by means of at least one sealed duct (15); a sealed chamber (19) defined between the outer door and the inner door, the sealed chamber configured to accommodate the sample carrier inserted by the insertion rod when the outer door and the inner door are in a sealed closed configuration; a transfer airlock (14) comprising: a fluid environment contained in the sealed chamber and a system for cleaning the sample carrier and the sample housed in the sealed chamber; A device comprising:

2. 2. The device of claim 1, wherein the exterior door comprises a gland (25) configured to be compressed in a sealing manner by the elongated portion of the insertion rod while allowing the insertion rod to move translationally.

3. The purification system comprises: a discharge valve (23) configured to discharge the fluid contained in said chamber down to a nominal pressure known as underpressure; a fill valve (24) configured to fill the chamber with a predefined fluid intended to fill the sealed enclosure up to another rated pressure known as high pressure; 3. The device according to claim 1 or 2, comprising:

4. 4. Device according to any one of claims 1 to 3, wherein the sample carrier comprises a cavity (11) into which the sample is intended to be inserted.

5. 5. The device of claim 4, wherein the sample carrier comprises a slot (12) that opens into the cavity and is configured to allow injection of a fluid into the cavity so as to force the sample out of the cavity.

6. 6. The device of claim 1, wherein the internal door is a sliding valve configured to slide between a closed position in which the internal door is closed in a sealed manner and an open position in which the internal door is open to allow passage of the sample carrier and the elongated portion of the insertion rod.

7. The interior door is 1.10 －５ 7. The device of claim 1, configured to maintain its closure sealed at a pressure of 1000 psi or less.

8. the gland comprises at least one, preferably at least two, sealing portions (27), clamping rings (26) and screws (28); 8. The device of claim 1, wherein the clamping ring is configured to compress the sealing portion when the screw is screwed in, which in turn compresses the elongated portion, thereby ensuring the sealing of the closure of the exterior door.

9. 9. A system comprising a sealed enclosure (1) and a device according to any one of claims 1 to 8, wherein the outer door (20) of the transfer airlock (14) is designed to open into the environment (M) outside the sealed enclosure, and the inner door (21) of the transfer airlock is designed to open directly or indirectly into the interior of the sealed enclosure via a sealed duct (15).

10. 10. The system of claim 9, wherein the system is a nuclear magnetic resonance (NMR) spectrometer and the sealed enclosure is a probe configured to excite atomic nuclei of a sample (E), preferably the probe configured to perform a dynamic nuclear polarization phenomenon.

11. 11. The system according to claim 10, comprising a rotor (6) on which the sample (E) is intended to be mounted, the rotor (6) being configured to be carried by the sample carrier, and the probe comprising a stator configured to rotate the rotor.

12. 12. The system of claim 11, wherein the probe comprises an air tube (16) connecting the transfer airlock to the stator and configured to displace the rotor of the sample carrier by propulsive force to the stator when inserted into the probe, and vice versa.

13. The following successive steps: a) placing a sample (E) in position on the sample carrier (10) of the insertion rod (7); b) inserting the sample carrier and the sample into the chamber (19) of the transfer airlock (14) through the outer door (20) with the inner door (21) sealed and closed; c) clamping the gland (25) to compress the elongated portion (8) so as to sealably close the exterior door; d) purifying the fluid contained in said chamber by said purification system; e) opening the inner door and inserting the sample carrier and the sample through the inner door into the sealed enclosure, the gland remaining clamped to compress around the elongated portion so as to maintain the outer door sealed closed; A method for operation of a system according to any one of claims 9 to 12, comprising:

14. The device for the insertion of the sample (E) is as claimed in claim 3 or as claimed in any one of claims 4 to 10 dependent on claim 3, wherein step d) comprises the following sub-steps: d １ ) opening the discharge valve (23) while the fill valve (24) is closed in order to discharge the fluid, e.g. gas, contained in the chamber (19) down to a nominal pressure, known as underpressure; d ２ ) closing the discharge valve (23); d ３ ) opening the fill valve (24) to fill the chamber with the fluid that constitutes the internal environment (5) of the sealed enclosure, for example, helium, having a purity of at least 99.999%, up to another rated pressure, known as high pressure; d ４ ) closing the fill valve (24); 14. The method of claim 13, comprising at least one repetition of

15. 15. The method according to claim 13 or 14, wherein the system is a system according to any one of claims 10 to 12 and comprises, after step e), a step g) of performing nuclear magnetic resonance spectroscopy of the sample (E).

16. and a subsequent step h) in which the sample (E) is removed from the sealed enclosure, said step h) comprising the following sub-steps: h １ a.) withdrawing the insertion rod to place the sample carrier and the sample in position in the chamber of the transfer airlock, the gland remaining clamped to compress the elongated portion so as to keep the sample carried by the sample carrier and the exterior door sealed closed; h ２ ) sealing the interior door closed; h ３ Optionally, opening the fill valve; h ４ a.) opening the gland to open the exterior door sufficiently to allow the sample carrier and the sample to pass through; h ５ a.) removing the sample carrier and the sample from the transfer airlock through the exterior door; and h ６ Optionally, placing the sample carrier back into position in the chamber of the transfer airlock, the sample being removed from the sample carrier, then closing the fill valve, if applicable, and clamping the gland to compress the elongated portion to sealably close the exterior door.

16. The method of any one of claims 13 to 15, comprising:

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