Attachment for HPLC capillary screw head

Abstract

An attachment for an HPLC capillary screw head, the attachment being configured to transfer torque from a torque tool to the HPLC capillary screw head, the HPLC capillary screw head being seated on an HPLC capillary, an HPLC capillary column, or an HPLC blind plug.

Description

[0001] The present invention relates to an attachment for an HPLC capillary screw head.

[0002] This attachment is used for the professional installation of capillaries for high performance liquid chromatography (HPLC), in particular Thermo(OR) Viper™ and nanoViper™ capillaries.

[0003] In high performance liquid chromatography (HPLC), HPLC capillaries, hereinafter referred to as "capillaries," are used to transport liquids, for example, into or out of an HPLC column. To secure such a capillary at its destination, the capillary has a fitting with an HPLC capillary screw head that sits on the capillary and is screwed to a counterpart at the destination. When screwed together, a sealing element of the fitting, e.g. an O-ring, which is located at the end of the capillary and the fitting, is pressed together to ensure the necessary tightness for HPLC operation. For this purpose, the end of the capillary, i.e. the corresponding part of the fitting, is usually designed to be relatively stable, for example as a metal end piece and / or a plunger. The counterpart to the fitting is also called a "port."

[0004] The capillaries may only be tightened to a specific torque to avoid damaging the system and to achieve a sufficient seal. For this purpose, the capillaries are tightened by hand, following the manufacturer's instructions, which can lead to varying tightening behavior depending on the user. For this purpose, some manufacturers offer a handle that can be attached to the capillary screw head. This handle is intended to facilitate manual tightening of the HPLC capillary screw head because it is easier to grip than the capillary screw head itself. Only the correct hand-tight pressing of the sealing element (such as an O-ring made of PEEK and / or other plastics) using the HPLC capillary screw head onto the port of a valve, an HPLC separation column, or another capillary creates a seal that is designed to withstand pressures of up to 1000 bar or even 1500 bar.

[0005] In practice, it is often observed that capillaries are not installed properly, for example, they are tightened too loosely and therefore do not seal properly. Users often subsequently tighten excessively, damaging the seal: the sealing element is damaged and becomes leaky and / or comes loose. In the worst case, the port at the installation location is also clogged and / or blocked by the broken sealing element, making it impossible to install another sealing element. This renders the capillaries and possibly the component at the installation location to which the capillary was connected, e.g., an HPLC column or a valve, unusable and must be replaced, which places a strain on resources and financial resources.

[0006] The object of the present invention is to at least partially remedy the aforementioned problems. The invention is defined by the claims, with the dependent claims being preferred embodiments.

[0007] In a first aspect, the present invention relates to an attachment for an HPLC capillary screw head, wherein the attachment is configured to transmit torque from a torque tool to the HPLC capillary screw head, wherein the HPLC capillary screw head is seated on an HPLC capillary. Alternatively, the HPLC capillary screw head can be seated on an HPLC capillary column or an HPLC blind plug.

[0008] A "torque tool" refers to a tool, such as a torque screwdriver or torque wrench, that can be used to apply a defined tightening torque to a fastener, such as a screw, and / or to indicate when the torque is reached and / or exceeded. It can be an indicating torque tool or a triggering torque tool. The torque tool can have a blade, a bit, an adapter, or similar.

[0009] The term "torque function" refers to the function of applying a defined tightening torque to a fastener, such as a screw, and / or indicating when it has been reached and / or exceeded. Torque tools therefore have a torque function.

[0010] “HPLC”, as already mentioned, is the abbreviation for high performance liquid chromatography.

[0011] An HPLC capillary is a tubing used in an HPLC system. Typical specifications are: inner diameter: 10–500 µm; outer diameter: 300 µm–1.3 mm; length: 50 mm–200 cm; material: metal or plastic, and combinations thereof, e.g., PEEK, stainless steel, fused silica, fused silica with PEEK sleeve, fused silica coated with polyimide, stainless steel with PEEK inlay, or stainless steel with polymeric inlay.

[0012] An "HPLC capillary screw head" is a part of the HPLC fitting, namely a connecting element that sits on the HPLC capillary and with which the HPLC capillary can be connected to a suitable counterpart, e.g., the port of a valve, an HPLC separation column, or another capillary. By screwing the HPLC capillary screw head to its counterpart, the necessary clamping force is generated to ensure tightness at operating pressure, which can be, for example, 1000 bar or 1500 bar. To ensure tightness, the HPLC capillary screw head and / or its counterpart preferably have a sealing ring that is clamped between the HPLC capillary screw head and its counterpart by the clamping force. Typical specifications of an HPLC fitting are: screw head with 10-32 UNF (2A or 2B) thread with 4-10 threads (i.e. thread outer diameter: approx. 3 / 16" (0.19"); tapered at the distal end and merging into 1 / 16 punch (ferrule), approx.4.5 mm plunger length with PEEK seal (approximately 1 mm in addition to the 4.5 mm plunger length) at the distal end; HPLC fitting length: 5-30 mm; Material: metal, e.g., stainless steel, plastic, e.g., PEEK plastic, and / or glass and / or carbon fiber reinforced plastic, as well as combinations. The HPLC screw head is often mounted on the capillary so that the capillary extends through the HPLC screw head along a central longitudinal axis of the screw head.

[0013] The attachment may include a first engagement element configured to engage a compatible second engagement element of the HPLC capillary screw head and, when engaged, to transmit torque. The first and second engagement elements may be engagement elements that conform to an industry standard and / or norm. Alternatively, they may be engagement elements that do not conform to an industry standard and / or norm. The second engagement element may be provided by the manufacturer and / or configured to tighten the HPLC capillary screw head to a compatible counterpart using a handle for manual tightening, e.g., as described above.

[0014] The attachment may include a third engagement element configured to engage a compatible fourth engagement element of the torque tool and, when engaged, to transmit the torque. The third and fourth engagement elements may preferably be engagement elements that conform to an industry standard and / or norm. Alternatively, they may be engagement elements that do not conform to an industry standard and / or norm. The fourth engagement element of the torque tool may be part of a blade, a bit, a socket, or the like.

[0015] The attachment is preferably configured to guide the HPLC capillary such that engagement between the third and fourth engagement elements is possible and / or engagement between the first and second engagement elements is possible.

[0016] The attachment may have a feedthrough opening, e.g. a lateral opening, configured to guide the HPLC capillary such that engagement between the third and fourth engagement elements is possible and / or engagement between the first and second engagement elements is possible.

[0017] Preferably, the first engagement element comprises a portion of the through-opening.

[0018] The first engagement element may be a male engagement element. The first engagement element may have a base on the remaining attachment, with the engagement element extending from the base away from the remaining attachment.

[0019] The first engagement element, which is a component of the attachment according to the invention, can have a plurality of engagement element sections, wherein the engagement element sections can be arranged around the section of the through-opening.

[0020] The second engagement element, which is part of the HPLC capillary screw head or is mounted thereon, can be spaced from an outer periphery of the HPLC capillary screw head and / or can be a female engagement element. The second engagement element can be a recess and / or a through-opening in the HPLC capillary screw head.

[0021] The attachment may extend from a proximal side having the third engagement element to a distal side having the first engagement element.

[0022] Preferably, the first engagement element is spaced from an outer periphery of the distal side.

[0023] The attachment may have a first contact surface. The first contact surface is preferably arranged on the distal side of the attachment. The first contact surface is preferably formed between the outer periphery of the distal side and the first engagement element, e.g., its base, spaced therefrom.

[0024] The second engagement element may have a second contact surface. The second contact surface is preferably formed between the outer circumference of the HPLC capillary screw head and the second engagement element spaced therefrom.

[0025] Preferably, the first and second contact surfaces are at least partially complementary to one another. Preferably, the first and second contact surfaces are configured to be in contact with one another when the first engagement element is engaged with the second engagement element. The dimensions of the first and second engagement elements are preferably also adapted to this. Preferably, the first and second contact surfaces are configured to stabilize engagement of the first and second engagement elements in a predetermined orientation, for example along the longitudinal axis. In other words, the contact surfaces can counteract tilting of the attachment out of the predetermined engagement position. The shape and / or dimensions of the first and second contact surfaces and / or of the first and second engagement elements are preferably selected to ensure this anti-tilting function.

[0026] The terms "proximal" and "distal" are location and / or direction specifications relative to the user. "Proximal" refers to something that is closer to the user during the process of screwing the HPLC capillary with the HPLC screw head to an installation location, rather than something referred to as "distal."

[0027] The attachment may have any suitable shape and size. For example, the attachment may have a substantially cylindrical basic shape with a base surface, a top surface, and a shell extending from the base surface to the top surface, wherein the base surface corresponds to the proximal side and the top surface corresponds to the distal side, and wherein the feedthrough opening extends through the shell from a central position on the distal side.

[0028] A "basic cylindrical shape" is considered the shape of a general cylinder. A general cylinder can be oblique, and / or have a base and / or ceiling of any shape, and / or be truncated at an angle. Examples include a right cylinder, an oblique cylinder, and a truncated cone.

[0029] "Substantially cylindrical shape": can describe a cylindrical shape with certain deviations that do not detract from the overall appearance, e.g., a surface texture consisting of grooves and / or dents and / or elevations. Alternatively or additionally, it can include deviations of up to 10% from the cylindrical shape. The shell, base, and / or top surface can be textured and / or curved.

[0030] If the attachment is designed as a cylinder with a circular base and top surface, it can have a radius of at least 3.5 mm and / or a maximum of 10 mm. The radius is preferably between 6 mm and 7 mm. The height of the cylinder can be at least 12 mm, preferably 25 mm.

[0031] The attachment can be designed as a cuboid, which corresponds to a right cylinder with a rectangular, e.g., square, base and top surface. One side length of the base and / or top surface can be at least 7 mm and / or a maximum of 20 mm, preferably between 12 and 15 mm. The diameter of the base can be between 7 mm and 20 mm from edge to edge. The height of the rectangular cylinder can be at least 12 mm, preferably 25 mm.

[0032] The attachment can be designed as a straight cylinder with a hexagonal base and top surface. One side of the base and / or top surface can be at least 3.5 mm and / or at most 10 mm. The diameter of the base can be 7 mm to 20 mm from edge to opposite edge. The height of the hexagonal cylinder can be at least 12 mm, preferably 25 mm.

[0033] The attachment can be designed as a straight cylinder with an octagonal base and top surface. One side length of the base and / or top surface can be at least 2.9 mm and / or at most 8.5 mm. The diameter of the base can be 7 mm to 20 mm from edge to opposite edge. The height of the octagonal cylinder can be at least 12 mm, preferably 25 mm.

[0034] The attachment can have a textured surface. The textured surface can, for example, have elevations and / or depressions, e.g., grooves and / or nubs. The textured surface can make the attachment easier to handle or improve such that the attachment can be better gripped with the fingers and torque can be better applied by hand, should this be necessary, for example when first attaching the attachment and / or when first manually tightening the capillary on a port. This applies in particular if the attachment has a size configured for manual tightening, in particular a diameter configured for this purpose. This can, for example, be the case for the shapes and dimensions of the attachments described herein.

[0035] The attachment can have a flattened area that can act as a rolling protection.

[0036] The feedthrough opening is preferably dimensioned such that the HPLC capillary can be guided through the feedthrough opening while maintaining its functionality, i.e., so that, for example, no kink occurs in the capillary. The feedthrough opening preferably has a length of at least 10 mm. The feedthrough opening can have a bend, wherein the bend preferably has a radius of at least 4 mm, more preferably at least 5 mm, and particularly preferably 6 mm. The bend can extend along the feedthrough direction of the capillary. The feedthrough opening can have a diameter of at least 350 µm and / or up to 2 mm, preferably 1.5 mm. The feedthrough opening can have a depth corresponding to half the diameter of the attachment plus half the diameter of the capillary.

[0037] Depth: Can be measured from the surface of the attachment to the bottom of the feedthrough opening, e.g. from the lateral surface of the hexagonal engaging element to the opposite wall of the slot (i.e. the bottom).

[0038] Lateral surface of the hexagon engagement element: corresponds to the lateral surface of the hexagon cylinder.

[0039] The through-opening can be configured to accommodate a capillary section of at least 10 mm in length. In other words, the through-opening can be dimensioned, in particular have a corresponding length, such that it can accommodate a capillary section of at least 10 mm in length. The through-opening can be designed as a channel. Accommodating a minimum length of the capillary and / or designing the through-opening as a channel can facilitate threading of the capillary and / or protect the capillary from damage and / or kinking. The through-opening can have a length of at least 10 mm, wherein the length can be measured as the shortest connection along a wall of the through-opening from an opening at the distal end of the first engagement element to an opening in the jacket. The length can be measured along the feed-through direction of the capillary.The through-opening may have a width of at least 350 µm, at least 400 µm, or at least 500 µm, wherein the width is measured perpendicular to a longitudinal axis, preferably a central longitudinal axis, of the attachment and perpendicular to the depth direction.

[0040] The first engagement element may be a male hexagon engagement element. The first engagement element may be one of the following: - 5 / 16 inch hex engaging element; - 1 / 4 inch hex engaging element; - 3 / 16 inch; - 1 / 4 inch; - 1 / 2 inch.

[0041] All of the above-mentioned sizes of the first engagement element can be hexagonal, 12-tooth, or multi-tooth. All of the above-mentioned sizes and / or shapes of the first engagement element can be male or female. For example, the first engagement element can be a male 3 / 16-inch hex engagement element.

[0042] The portion of the through-opening provided by the first engagement element may be formed as a slot extending from a lateral surface of the first engagement element toward the center axis of the first engagement element and optionally up to the center axis of the first engagement element and / or beyond, preferably up to the center axis plus half the diameter of the capillary.

[0043] The portion of the through-opening provided by the first engagement element may be formed as a slot extending from a lateral surface of the hexagon engagement element to the central axis of the hexagon engagement element and beyond, preferably to the central axis plus half the diameter of the capillary.

[0044] The through-opening may have a portion extending through a portion of the attachment different from the first engagement element.

[0045] The third engagement element may be a female engagement element. The third engagement element may be a recess and / or a through-opening in the attachment.

[0046] The fourth engagement element may be a male engagement element.

[0047] The third engagement element may be a standardized engagement element and / or configured to engage with one of the following fourth engagement elements: - a 1 / 4 inch square socket - a 1 / 4 inch external square - a 1 / 2 inch square socket - a 1 / 2 inch external square - a 3 / 8 inch square socket - a 3 / 8 inch external square - a 5 / 16 inch square socket - a 5 / 16 inch external square - a 4-14 mm hexagon socket - a 4-14 mm external hexagon - a 4-14 mm internal octagon - a 4-14 mm external octagon - a 4-14 mm internal ten-square - a 4-14 mm external ten-square - a 4-14 mm internal twelve-point - a 4-14 mm external twelve-point - External Torx (E-socket) - Internal Torx (E-socket) - a thread; - the fourth engaging element is part of a blade of a torque screwdriver; - the fourth engagement element is part of a torque screwdriver without a blade, ie part of a torque screwdriver handle with torque function, such as a ¼ inch bit holder

[0048] The third engagement element can be one of the following engagement elements: - a 1 / 4 inch square socket - a 1 / 4 inch external square - a 1 / 2 inch square socket - a 1 / 2 inch external square - a 3 / 8 inch square socket - a 3 / 8 inch external square - a 5 / 16 inch square socket - a 5 / 16 inch external square - a 4-14 mm hexagon socket - a 4-14 mm external hexagon - a 4-14 mm internal octagon - a 4-14 mm external octagon - a 4-14 mm internal ten-square - a 4-14 mm external ten-square - a 4-14 mm internal twelve-point - a 4-14 mm external twelve-point - External Torx (E-socket) - Internal Torx (E-socket) - a thread, preferably with one turn in the same direction as the thread of the HPLC capillary screw head; - the third engagement element is part of a blade configured to engage with a torque screwdriver handle with torque function.

[0049] The attachment can have a length across the entire body of at least 17 mm. Alternatively or additionally, the attachment can have a length across the entire body of a maximum of 1000 mm, a maximum of 500 mm, a maximum of 300 mm, a maximum of 200 mm, or a maximum of 100 mm, or any value in 1 mm increments between 1000 mm and 17 mm. Longer attachments are also possible. Preferably, the attachment has a length of 25 mm to 35 mm, most preferably approximately 30 mm.

[0050] The attachment can have a magnet and / or be magnetic. This can facilitate engagement with the torque tool and / or the HPLC capillary screw head.

[0051] To tighten the capillary using the attached capillary screw head to a compatible counterpart, the attachment according to the invention is engaged with a commercially available torque tool, e.g., a torque screwdriver, and the capillary screw head. The correct tightening torque, e.g., approximately 0.15–0.25 Nm, is preset in the torque tool, and the user simply needs to tighten. Once the correct tightening torque is reached, the torque tool rotates or indicates that the torque has been reached, and the user can stop tightening.

[0052] The attachment enables professional installation using a predefined torque, e.g. approximately 0.05-0.5 Nm, e.g. 0.05-0.35 Nm, e.g. 0.1-0.3 Nm, preferably 0.15-0.25 Nm, and thus prevents both under-tightening and over-tightening of the capillaries.

[0053] The present invention enables the installation of HPLC capillaries in the intended manner, neither too tight nor too loose. This prevents damage to the capillaries, screw heads, and counterparts. It also protects users' fingers, as installing capillaries / fittings puts strain on the skin and can lead to sore fingers if several capillaries are replaced in quick succession.

[0054] According to a second aspect, the invention relates to an attachment as described above and with an integrated torque function. The torque function can be implemented in any suitable manner.

[0055] To use the invention according to the second aspect, the attachment can be configured to engage with a tool for exerting torque, for example, a conventional, compatible screwdriver. In other words, a tool without a torque function can be used instead of the torque tool.

[0056] According to a third aspect, the present invention relates to a set comprising: - an essay as described above; and - a compatible torque tool.

[0057] According to a fourth aspect, the invention relates to a torque tool, preferably a torque screwdriver, with an integrated attachment as described above.

[0058] A fifth aspect relates to a method for mounting an HPLC capillary with an HPLC capillary screw head by means of a compatible attachment as described above to a counterpart compatible with the HPLC capillary screw head, comprising the following steps: - Place the attachment on the HPLC capillary screw head; - optionally attaching a torque tool to the attachment; - optionally attaching the HPLC capillary screw head to the compatible port; - Tighten the HPLC capillary screw head, whereby a specified tightening torque is set in the torque tool during tightening.

[0059] The tightening of the HPLC capillary screw head can be achieved by the user applying a torque to the torque tool by hand, which transfers the torque to the HPLC capillary screw head via the attachment.

[0060] The method may comprise the step: - Setting a target torque in the torque tool.

[0061] If it is a triggering torque tool, the torque tool automatically ensures that the set target torque is not exceeded by spinning when the set target torque is exceeded.

[0062] If it is an indicating torque tool, the procedure may include the additional step: - End the tightening step when the torque tool indicates that the set target torque has been reached and / or exceeded.

[0063] According to one method, the following steps are carried out to mount an HPLC capillary on which an HPLC capillary screw head is seated, using the attachment according to the invention with integrated torque function described herein, to a port compatible with the HPLC capillary screw head: - Attaching the attachment with integrated torque function to the HPLC capillary screw head; - optionally attaching a turning tool, e.g. a screwdriver, to the attachment with integrated torque function; - optionally attaching the HPLC capillary screw head to the compatible port; - Tightening the HPLC capillary screw head, whereby a specified tightening torque is set in the attachment with integrated torque function during tightening.

[0064] The method may comprise the step: - Setting a target torque in the attachment with integrated torque function.

[0065] If it is a triggering torque function, this automatically ensures that the set target torque is not exceeded by causing the attachment to spin when the set target torque is exceeded.

[0066] If it is an indicating torque function, the procedure may include the additional step: - End the tightening step when the attachment with integrated torque function indicates that the set target torque has been reached and / or exceeded.

[0067] According to one method, the following steps are carried out to disassemble an HPLC capillary on which an HPLC capillary screw head is seated, which is screwed to a compatible port, from the port compatible with the HPLC capillary screw head by means of an attachment according to the invention described herein: - Place the attachment on the HPLC capillary screw head; - optionally placing a turning tool, e.g. a screwdriver, on the attachment; - Loosen the screw connection of the HPLC capillary screw head from the port by applying a sufficiently large torque to the HPLC capillary screw head using the attachment and, if available, the turning tool.

[0068] The turning tool can be a torque tool.

[0069] The advantages of the second to fifth aspects of the invention are the same as those of the first aspect. Furthermore, the second and fourth aspects of the invention eliminate the need to engage the attachment with the torque tool, which further simplifies handling and saves time. In contrast, an advantage of the first and third aspects of the invention is that the torque tool can be a commercially available standard tool.

[0070] The sources mentioned in this description in their entirety as well as the cited references are included in this description.

[0071] The invention is further explained with reference to the figures. All dimensions in the figures are exemplary and, unless otherwise stated, are in millimeters. Fig. Figure 1 shows an example of a commercially available HPLC capillary with HPLC capillary screw head in (a) lateral view, and (b) in a sectional view along the central longitudinal axis of the capillary screw head as in Fig. 1a indicated by A; Fig. 2 shows a 3D view of an embodiment of the attachment according to the invention; Fig. 3 shows a view of the distal side of the embodiment of the attachment from Fig. 2; Fig. 4 shows a view of a proximal side of the embodiment of the attachment of Fig. 2; Fig. Figure 5 shows a view of a lateral side of the embodiment of the attachment of Fig. 2; Fig. 6 shows a sectional view of the embodiment of the attachment from Fig. 5, section A; Fig. 7 shows the views from the Fig. 3 (top) and 6 (bottom) with exemplary dimensions; Fig. 8 shows views of a use of the attachment from the Fig. 3-6 with a conventional torque screwdriver (only the interacting engagement element of the torque screwdriver is shown; cf. Fig. 9 and Fig. 10 for an exemplary overall view) for tightening an HPLC capillary by means of an HPLC capillary screw head on a compatible counterpart; (a) lateral view; (b) exploded view in the same viewing direction as (a); (c) lateral exploded view with opposite viewing direction to (a); (d) section AA, as drawn in (a) and (c), ie along the longitudinal axis; Fig. 9 shows a view of a use of an embodiment of the attachment according to the invention with a torque wrench with a torque tool standard adapter; Fig. 10 shows a view of the use of an embodiment of the attachment according to the invention with a torque wrench without a torque tool standard adapter (e.g. with bit holder, e.g. ¼ inch hexagon); Fig. 11 shows views of an embodiment of the attachment according to the invention, (a) side view looking in the depth direction of the through opening, (b) section AA from Fig. 11a, ie along the long axis, (c) view of the proximal side, (d) view of the distal side.

[0072] A typical example of an HPLC capillary 100 (cut off on the left in the figure) with a fitting 102 with HPLC capillary screw head 104 and plunger (ferrule) 105 is shown in the views in Fig. 1 shown.

[0073] Fig. Figure 2 shows an attachment 200 according to the present invention in a three-dimensional (i.e., 3D) view. The attachment 200 may, as shown, have a substantially cylindrical basic shape, with a distal side 202, a proximal side 204 (see Fig. 4, is in Fig. 2) and a jacket 206 extending from the proximal side 204 to the distal side 202. The jacket may be textured, e.g., ridged (as shown), to provide improved grip. This may be advantageous when the attachment 200 is used for manually tightening the capillary screw head 104. Fig. 3 shows a view of the distal side 202. Fig. 5 shows a lateral view in a depth direction of a through opening 212, which will be described in detail below. Fig. 6 shows the section AA as in Fig. 5, ie along a longitudinal axis 216 of the attachment 200.

[0074] The attachment 200 may include a first engagement element 208 located on and / or extending from the distal side 202. The first engagement element 208 may, for example, be configured to be placed onto a capillary screw head 104, e.g., to be engaged with the capillary screw head 104, such that the transmission of torque from the attachment 200 to the capillary screw head 104 is possible. For example, the first engagement element 208 may be configured to be engaged with a compatible second engagement element 106 of the capillary screw head 104. For example, the first engagement element 208 may be a male engagement element that extends from a base on the distal side 202 away from the distal side 202. The second engagement element 106 may be a female engagement element formed as a recess in the capillary screw head 104 (see Fig. 1). The edges of the first engagement element 208 can be chamfered. The first engagement element 208 can be configured in any suitable shape, for example (as shown) as a hexagonal engagement element, and for example as a male (as shown) or female engagement element. Other shapes are possible, for example, any common size and shape of screwing tools, as previously described, as long as a rotationally fixed engagement with the capillary screw head 104 can be established and / or the diameter of the first engagement element 208 fits into the capillary screw head 104.

[0075] The attachment 200 can have a first contact surface. The first contact surface is preferably arranged on the distal side 202 of the attachment. The first contact surface is preferably formed between the outer periphery of the distal side 202 and the first engagement element 208, for example, its base, spaced therefrom. As shown in the figures, the distal side 202 can be configured as a first contact surface. The distal side 202 can also be configured as a first contact surface only in sections.

[0076] The second engagement element 106 may have a second contact surface. The second contact surface is preferably formed between the outer circumference of the HPLC capillary screw head 104 and the second engagement element 106 spaced therefrom.

[0077] Preferably, the first and second contact surfaces are at least partially complementary to one another. Preferably, the first and second contact surfaces are configured to be in contact with one another when the first engagement element 208 is engaged with the second engagement element 106. Preferably, the first and second contact surfaces are configured to stabilize engagement of the first engagement element 208 with the second engagement element 106 in a predetermined orientation, for example, along the longitudinal axis. In other words, the contact surfaces can counteract tilting of the attachment 200 from the predetermined engagement position. The dimensions of the first and second contact surfaces, and / or of the first and second engagement elements, are preferably selected to ensure this anti-tilting function.For example, the dimensions of the engagement elements can be selected such that they do not block contacting of the contact surfaces, as would be the case if the first engagement element 208 were too long and significantly exceeded the length of the second engagement element 106.

[0078] In the case of a male first engagement element 208, the first contact surface on the distal side 202 can be at least partially complementary to the material edge of the HPLC capillary screw head 104, which defines the complementary female engagement element. The same applies analogously if the engagement element is a female first engagement element 208 and a male second engagement element 106. When the first engagement element 208 is engaged with the second engagement element 106, the first and second contact surfaces touch each other. Tilting of the attachment out of the intended engagement position, e.g., out of the axial direction, is thereby made more difficult or even prevented. Associated problems, e.g., canting of the attachment 200 in the capillary screw head 104, can thereby be reduced.

[0079] The attachment 200 may have a third engagement element 210, see. Fig. 4. The third engagement element 210 can be configured to be used with a commercially available torque tool 300 (see Fig. 8) to engage, so that the transmission of torque from the torque tool 300 to the attachment 200 is possible. In particular, the third engagement element 210 can be configured to engage with a compatible fourth engagement element 302 of the torque tool 300. In Fig. 8(a) shows the torque tool 300 engaged with the attachment 200. The attachment 200 is also engaged with the capillary screw head 104. If the torque tool 300 is now rotated (indicated by a thick, solid arrow), a torque is transferred via the attachment 200 to the capillary screw head 104, so that the capillary screw head can be properly tightened to a suitable counterpart. In particular, the correct tightening torque can be ensured by setting the target torque in the torque tool. Fig. 8(b) shows the view from Fig. 8(a) again as an exploded view (explosion along the central longitudinal axis 216).

[0080] Preferably, the third engagement element 210 is designed in shape and size according to a common standard. The edges of the third engagement element 210 can be chamfered. The attachment 200 can have a (in connection with Fig. 5 already mentioned) through-opening 212. The first engagement element 208 can have a section 212a of the through-opening 212, i.e., define a section of the through-opening 212. The through-opening 212 can have a section 212b that is different from the section 212a in the first engagement element 208. The through-opening 212 can extend from the first engagement element 208, for example, from an opening 218 at a distal end of the first engagement element 208, to an opening 214 in the casing 206. For example, the through-opening 212 can be formed as a slot through a surface of the attachment 200. The slot can extend from the surface of the attachment 200 in a depth direction, for example, to a longitudinal axis 216, preferably a central longitudinal axis 216, of the attachment 200 and optionally beyond. The depth direction may be defined as the direction to the nearest point on the longitudinal axis 216 of the attachment 200. Fig. Figure 8(c) shows an exploded view looking opposite to the direction of view in Fig. 8(b). Fig. In Figure 8(c), the through-hole 212 can be seen and the viewing direction is in the depth direction of the through-hole 212. The capillary 100 is only partially shown. Fig. 8(d) shows the section AA as in Fig. 8(a), ie along the central longitudinal axis 216. Here, the through opening 212 can be seen perpendicular to the depth direction.

[0081] The dimensions of the through-opening 212 can be adapted to the specifications, in particular the outer diameter and flexural rigidity, of the capillary 100. The through-opening 212 can have a shape and size that can accommodate a capillary section of at least 10 mm in length. The through-opening 212 can be designed as a channel. Accommodating a minimum length of the capillary 100 and / or designing the through-opening 212 as a channel can help facilitate threading of the capillary 100 into the through-opening 212 and / or advantageously guide the capillary 100 in the through-opening 212 and protect the capillary 100 from damage and / or kinking.The through-opening 212 may have a length of at least 10 mm, wherein the length may be measured as the shortest connection along a wall of the through-opening 212 from the opening 218 at the distal end of the first engagement element 208 to the opening 214 in the jacket 206. The through-opening 212 may have a width of at least 350 µm, wherein the width is measured perpendicular to the (preferably central) longitudinal axis 216 and perpendicular to the depth direction.

[0082] When viewing the through-opening 212 in a sectional plane, for example in the Fig. 7 (i.e., a cutting plane along the central longitudinal axis 216 and along the depth direction of the through-opening 212), the through-opening may have the following specifications and / or dimensions: - The wall 220 of the attachment 200 delimiting the through-opening 212 extends in a distal section 220a from the opening 218 at the distal end of the first engagement element 208 in the direction of the proximal side 204, preferably parallel to the longitudinal axis 216 of the attachment 200 and / or preferably over a length of at least 2 mm, or at least 3 mm, or at least 4 mm, preferably at least 5 mm, particularly preferably at least 10 mm, more preferably between 14 and 15 mm, up to a point P. - The wall 220 of the attachment 200, which defines the through-opening 212, extends in a proximal section 220b from point P along a curved path, e.g., a circular path, to the opening 214 in the casing 206 of the attachment 200, preferably over a length of 9.4 mm. The circular path can have a radius R of preferably 6 mm. The center point of the circular path can be located on the casing 206. - The distance between the wall 220 and the (preferably central) longitudinal axis 216 in the distal section 220a can be half the capillary diameter, but at least 175 µm, preferably 250 µm, more preferably 500 µm, most preferably 750 µm, wherein the longitudinal axis 216 can be located between the wall 220 and the opening 214 in the casing 206. The proximal section 220b of the wall 220 can have one-third, one-quarter, one-sixth, or one-eighth of a circle. - The length of the attachment, measured from a proximal to a distal end, can be 17 mm - 1000 mm, e.g. preferably 30 mm

[0083] When viewing the through-opening 212 in a sectional plane, for example in a sectional plane perpendicular to the (preferably central) longitudinal axis 216 and in the section 212a of the through-opening 212 located in the first engagement element, the through-opening 212, i.e. the cross-section of the through-opening 212, can have the following specifications and / or dimensions: - The through-opening may essentially have the shape of a test tube, or the wall 220 delimiting the through-opening may essentially have a U-shape. - The distance between the legs of the U-shape can be at least 350 µm, e.g. preferably 1.5 mm. - The depth of the U-shape can be half the diameter of the attachment plus half the diameter of the capillary, e.g., preferably 2.675 mm. In the case of a straight, round cylinder as the shell 206 of the attachment, the diameter of the cylinder is used as the diameter, even if there is a flattened portion 206a (see below), i.e., without taking into account the reduction in diameter due to the flattened portion.

[0084] When viewing the through-opening 212 in a sectional plane, for example, in a sectional plane perpendicular to the (preferably central) longitudinal axis 216 and in the section 212b of the through-opening 212 that is located outside the first engagement element and passes through the distal section 220b of the wall 220, the through-opening 212, i.e. the cross-section of the through-opening 212, can have the following specifications and / or dimensions: - The through-opening may essentially have the shape of a test tube, or the wall 220 delimiting the through-opening may essentially have a U-shape. - The distance between the legs of the U-shape can be at least 350 µm, e.g. preferably 1.5 mm. - The depth of the U-shape can be half the diameter of the attachment plus half the diameter of the capillary, e.g., at least 3.675 mm and a maximum of 10.65 mm, e.g., preferably 6.175 mm. In the case of a straight, round cylinder as the shell 206 of the attachment, the diameter of the cylinder is used as the diameter, even if there is a flattened portion 206a (see below), i.e., without taking into account the reduction in diameter due to the flattened portion.

[0085] When viewing the through-opening 212 in a sectional plane, for example, in a sectional plane perpendicular to the (preferably central) longitudinal axis 216 and in the section 212b of the through-opening 212 that is located outside the first engagement element and passes through the proximal section 220b of the wall 220, the through-opening 212, i.e. the cross-section of the through-opening 212, can have the following specifications and / or dimensions: - The through-opening may essentially have the shape of a test tube, or the wall 220 delimiting the through-opening may essentially have a U-shape. - The distance between the legs of the U-shape can be at least 350 µm, e.g. preferably 1.5 mm. - The depth of the U-shape can be between half the diameter of the attachment plus half the diameter of the capillary, e.g. at least 3.675 mm and a maximum of 10.65 mm, e.g. preferably 6.175 mm, at point P and 0 at the proximal end of the through hole.

[0086] The attachment can have the shape and dimensions as in Fig. 7 shown.

[0087] The attachment 200 can be made of solid material. The attachment 200 can be free of cavities, except for the through-opening 212 and, if applicable, the first and / or third engagement elements 208, 210.

[0088] The attachment 200 may comprise or consist of a sponge-like and / or porous but dimensionally stable material.

[0089] The attachment 200 may comprise one or a combination of the following materials: metal, polymer, glass, wood, composites.

[0090] The third engagement element 210 is preferably free from a portion of the through opening 212.

[0091] The casing 206 can optionally have a flattened portion 206a. One advantage of the presence of the flattened portion 206a is that it prevents the attachment 200 from rolling away when the attachment 200 is put down. A distance of the (preferably central) longitudinal axis 216 to the nearest point of the flattened portion 206 can be at least 1.5 mm, for example preferably 5 mm. The flattened portion 206a can be located, for example, on a side of the casing 206 opposite the through-opening 212. The flattened portion can be unperforated by the through-opening 212 and / or can not touch the through-opening. Alternatively or additionally, the flattened portion 206a can extend on any side of the casing 206, for example such that the flattened portion 206a is perforated and / or touched by the through-opening 212.

[0092] Fig. 9 shows an embodiment of the attachment 200 in use with a torque tool 300 provided with a torque tool standard adapter 304. The torque tool standard adapter 304 is interchangeable and standardized, so that the torque tool can be adapted to various other standard tools and / or standard accessories (e.g., screw types) using different torque standard adapters 304. The fourth engagement element 302 is located here on the torque tool standard adapter 304, preferably at its distal end. The torque tool standard adapter 304 is assigned to the torque tool 300 here.

[0093] In Fig. Figure 10 shows an embodiment of an attachment 200 in use with a torque tool 300 that is not equipped with a standard torque tool adapter. The fourth engagement element 302 is located on the torque tool 300 and, unlike the standard torque tool adapter 304, is not designed to be changed by the user.

[0094] Fig. 11 shows four views of the attachment 200 from Fig. 10. The attachment 200 may be provided with a female first engagement element on the distal side 202 of the attachment 200 and with a female second engagement element 210 on the proximal side 204 of the attachment 200, as shown.

[0095] According to a further aspect, the present invention relates to a set comprising an attachment 200 and a torque tool, preferably a torque screwdriver 300.

[0096] According to one method, the following steps are carried out to mount an HPLC capillary 100, on which an HPLC capillary screw head is seated, to a port compatible with the HPLC capillary screw head using the attachment 200 according to the invention described herein: - Place the attachment 200 onto the HPLC capillary screw head 104; - Place a torque tool, e.g. a torque screwdriver 300, on the attachment 200; - optionally attaching the HPLC capillary screw head 104 to the compatible port; - Tighten the HPLC capillary screw head 104, whereby a specified tightening torque is set in the torque tool during tightening.

[0097] The tightening of the HPLC capillary screw head 104 can be achieved by the user manually applying torque to the torque tool, which transmits the torque to the HPLC capillary screw head 104 via the attachment.

[0098] The method may comprise the step: - Setting a target torque in the torque tool.

[0099] If it is a triggering torque tool, the torque tool automatically ensures that the set target torque is not exceeded by spinning when the set target torque is exceeded.

[0100] If it is an indicating torque tool, the procedure may include the additional step: - End the tightening step when the torque tool indicates that the set target torque has been reached and / or exceeded.

[0101] According to a further aspect, the present invention relates to an attachment 200 with integrated torque function.

[0102] According to one method, the following steps are carried out to mount an HPLC capillary 100, on which an HPLC capillary screw head is seated, to a port compatible with the HPLC capillary screw head 104 using the inventive attachment 200 with integrated torque function described herein: - Attaching the attachment 200 with integrated torque function to the HPLC capillary screw head 104; - optionally attaching a rotary tool, e.g. a screwdriver, to the attachment 200 with integrated torque function; - optionally attaching the HPLC capillary screw head 104 to the compatible port; - Tightening the HPLC capillary screw head 104, whereby a specified tightening torque is set in the attachment 200 with integrated torque function during tightening.

[0103] The method may comprise the step: - Setting a target torque in the attachment 200 with integrated torque function.

[0104] If it is a triggering torque function, this automatically ensures that the set target torque is not exceeded by rotating the attachment 200 when the set target torque is exceeded.

[0105] If it is an indicating torque function, the procedure may include the additional step: - End the tightening step when the 200 attachment with integrated torque function indicates that the set target torque has been reached and / or exceeded.

[0106] Analogously, in the case of a torque tool with integrated attachment 200, the method may comprise the following steps to mount an HPLC capillary 100, on which an HPLC capillary screw head 104 is located, by means of a torque tool with integrated attachment 200 to a port compatible with the HPLC capillary screw head 104: - Place the attachment 200 integrated into the torque tool onto the HPLC capillary screw head 104; - optionally attaching the HPLC capillary screw head 104 to the compatible port; - Tightening the HPLC capillary screw head 104, whereby a specified tightening torque is set in the torque tool with integrated attachment 200 during tightening.

[0107] The method may comprise the step: - Setting a target torque in the torque tool with integrated attachment 200.

[0108] If the torque tool has a triggering torque function, this automatically ensures that the set target torque is not exceeded by rotating the 200 attachment when the set target torque is exceeded.

[0109] If it is an indicating torque function, the procedure may include the additional step: - End the tightening step when the torque tool with integrated attachment 200 indicates that the set target torque has been reached and / or exceeded.

[0110] Below is a list of preferred embodiments of the invention: 1. An attachment for an HPLC capillary screw head, the attachment being configured to transfer torque from a torque tool to the HPLC capillary screw head, the HPLC capillary screw head being seated on an HPLC capillary. 2. The attachment of aspect 1, wherein the attachment comprises a first engagement element configured to engage a compatible second engagement element of the HPLC capillary screw head and, when engaged, to transmit the torque. 3. An attachment according to any one of the preceding aspects, wherein the attachment comprises a third engagement element configured to engage a compatible fourth engagement element of the torque tool and, when engaged, to transmit the torque. 4. The attachment according to any one of aspects 2 or 3, wherein the attachment is configured to guide the HPLC capillary such that engagement between the third and fourth engagement elements is possible and / or engagement between the first and second engagement elements is possible. 5. The attachment according to the preceding aspect, wherein the attachment has a through-opening, e.g., a lateral opening, configured to guide the HPLC capillary such that engagement between the third and fourth engagement elements is possible and / or engagement between the first and second engagement elements is possible. 6. The attachment of aspect 5, wherein the first engagement element comprises a portion of the through-opening. 7. An attachment according to any one of aspects 2-6, wherein the first engagement element is a male engagement element. 8. The attachment according to any one of aspects 6-7, wherein the first engagement element has a plurality of engagement element portions, wherein the engagement element portions are arranged around the portion of the through-opening. 9. The attachment according to any one of aspects 2-8, wherein the second engagement element is spaced from an outer periphery of the HPLC capillary screw head and / or is a female engagement element. 10. The attachment of any one of aspects 2-9, wherein the attachment extends from a proximal side having the third engagement element to a distal side having the first engagement element, and preferably wherein the first engagement element is spaced from an outer periphery of the distal side. 10a. Attachment according to one of the preceding aspects, wherein the attachment has a first contact surface, preferably on the distal side, particularly preferably between the outer circumference of the distal side of the attachment and the first engagement element; and / or wherein the HPLC capillary screw head has a second contact surface, preferably between its outer circumference and the second engagement element. 10b. Attachment according to aspect 10a, wherein the first contact surface is at least partially complementary to the second contact surface; and / or wherein the first contact surface is configured to be in contact with the second contact surface when the first engagement element is engaged with the second engagement element; and / or wherein the first contact surface and the second contact surface are configured to make it difficult, preferably to prevent, tilting of the first engagement element relative to the second engagement element out of the intended engagement position. 11. An attachment according to aspect 10, 10a or 10b, depending on aspect 5, wherein the attachment has a substantially cylindrical basic shape with a base surface, a cover surface and a jacket extending from the base surface to the cover surface, wherein the base surface corresponds to the proximal side and the cover surface corresponds to the distal side, and wherein the feedthrough opening extends from a central position on the distal side through the jacket. 12. Attachment according to one of aspects 5-10, wherein the through-opening has a length of at least 5 mm, preferably at least 10 mm. 13. An attachment according to any one of aspects 5-11, wherein the through-opening has a bend, wherein the bend preferably has a radius of 6 mm. 14. An attachment according to any one of aspects 5-12, wherein the feedthrough opening has a width of at least 350 µm. 15. An attachment according to any one of aspects 5-14, wherein the through-opening has a depth of at least half the diameter of the attachment, preferably at least half the diameter of the attachment plus half the diameter of the capillary. 16. The attachment of any of aspects 6-15, wherein the first engagement element is a male or female engagement element; and / or wherein the first engagement element is a hex, 12-tooth, or multi-tooth engagement element; and / or wherein the first engagement element has one of the following sizes: 5 / 16 inch, 1 / 4 inch, 3 / 16 inch, 1 / 4 inch, 1 / 2 inch. 17. An attachment according to any one of aspects 6-16, wherein the portion of the through-opening having the first engagement element is formed as a slot extending from a lateral surface of the first engagement element toward the center axis of the first engagement element and optionally to and / or beyond the center axis of the first engagement element. 18. The attachment of aspect 17 in combination with claim 16, wherein the portion of the through-opening having the first engagement member is formed as a slot extending from a lateral surface of the hex engagement member to and beyond the central axis of the hex engagement member. 19. The attachment according to any one of aspects 5-18, wherein the through-opening has a portion extending through a portion of the attachment different from the first engagement element. 19a.The attachment of any of aspects 5-19, wherein the feedthrough opening is configured to accommodate a capillary section of at least 10 mm in length. 20. The attachment of any one of aspects 3-19, wherein the third engagement element is a female engagement element or the fourth engagement element is a male engagement element. 21. An attachment according to any one of aspects 3-19, wherein the third engagement element is a standardized engagement element and / or is configured to engage with one of the following fourth engagement elements: - a 1 / 4 inch square socket - a 1 / 4 inch external square - a 1 / 2 inch square socket - a 1 / 2 inch external square - a 3 / 8 inch square socket - a 3 / 8 inch external square - a 5 / 16 inch square socket - a 5 / 16 inch external square - a 4-14 mm hexagon socket - a 4-14 mm external hexagon - a 4-14 mm internal octagon - a 4-14 mm external octagon - a 4-14 mm internal ten-square - a 4-14 mm external ten-square - a 4-14 mm internal twelve-point - a 4-14 mm external twelve-point - External Torx (E-socket) - Internal Torx (E-socket) - a thread; - the fourth engaging element is part of a blade of a torque screwdriver; the fourth engaging element is part of a torque screwdriver without a blade, i.e. part of a torque screwdriver handle with torque function. 22. An attachment according to any one of aspects 3-19, wherein the third engagement element is a standardized engagement element, for example one of the following engagement elements: - a 1 / 4 inch square socket - a 1 / 4 inch external square - a 1 / 2 inch square socket - a 1 / 2 inch external square - a 3 / 8 inch square socket - a 3 / 8 inch external square - a 5 / 16 inch square socket - a 5 / 16 inch external square - a 4-14 mm hexagon socket - a 4-14 mm external hexagon - a 4-14 mm internal octagon - a 4-14 mm external octagon - a 4-14 mm internal ten-square - a 4-14 mm external ten-square - a 4-14 mm internal twelve-point - a 4-14 mm external twelve-point - External Torx (E-socket) - Internal Torx (E-socket) - a thread, preferably with one turn in the same direction as the thread of the HPLC capillary screw head; - the third engagement element is part of a blade configured to engage with a torque screwdriver handle with torque function. 23. An attachment according to any one of the preceding aspects, wherein the attachment has the following dimensions: - as a cylinder with a circular base and top surface: a radius of at least 4 mm and / or a maximum of 10 mm; a cylinder height of 12 mm to 995 mm; - as a cuboid (ie a right cylinder with a rectangular or square base and top surface): a side length of the base and / or top surface of at least 7 mm and / or a maximum of 20 mm; a height of the cylinder of at least 12 mm; - as a right cylinder with a hexagonal base and top surface: a side length of the base and / or top surface of at least 3.5 mm and / or a maximum of 10 mm; a diameter of the base and / or top surface of 7 to 20 mm; a height of the hexagonal cylinder of 12 mm to 995 mm; - as a right cylinder with octagonal base and top surface: a side length of the base and / or top surface of at least 2.9 mm and / or a maximum of 8.5 mm; a diameter of the base and / or top surface of 7 to 20 mm; a height of the octagonal cylinder of 12 mm to 995 mm. 24. An attachment according to any one of the preceding aspects, wherein the attachment has a length over the entire body of - at least 17 mm; and / or - maximum 1000 mm, maximum 500 mm, maximum 300 mm, maximum 200 mm, or maximum 100 mm, or any value in 1 mm increments between 1000 mm and 17 mm. 24a.Attachment according to one of the preceding aspects, wherein the attachment has a structured surface, preferably a structured lateral surface, wherein the structured surface preferably has elevations and / or depressions, for example grooves and / or knobs. 24b. An attachment according to any preceding aspect, wherein the attachment is configured in shape and size to allow a user to grasp the attachment with fingers and apply torque from the fingers directly to the attachment. 25. Attachment according to any of the preceding aspects with integrated torque function. 26. Set that features: - an essay according to one of the preceding aspects; and - a compatible torque tool. 27. Torque tool with integrated attachment according to any of the preceding aspects without aspect 13. 28. A method for mounting an HPLC capillary with an HPLC capillary screw head by means of a compatible attachment according to one of the preceding aspects on a counterpart compatible with the HPLC capillary screw head, comprising the following steps: - Place the attachment on the HPLC capillary screw head; - Place a torque tool on the attachment; - Tighten the HPLC capillary screw head, whereby a specified tightening torque is set in the torque tool during tightening. List of reference symbols: 100 HPLC capillaries (capillaries for short) 102 HPLC fitting 104 HPLC capillary screw head (short capillary screw head, or screw head) 105 stamps 106 second engagement element 200 essay 202 distal side of the attachment 204 proximal side of the attachment 206 Coat of the essay 208 first engagement element 210 third engagement element 212 passage opening 212a Section of the through opening in the first engagement element 212b Section of the passage opening which is different from section 212a 214 Opening in the jacket 216 (preferably central) longitudinal axis of the attachment 218 Opening at the distal end of the first engagement element 220 wall defining the passage opening 220a distal section of the wall defining the passage opening 220b proximal section of the wall defining the passage opening 300 torque tool 302 fourth engagement element 304 standard adapter for torque tool

Claims

[1] An attachment for an HPLC capillary screw head, the attachment being configured to transmit torque from a torque tool to the HPLC capillary screw head, the HPLC capillary screw head being seated on an HPLC capillary, an HPLC capillary column, or an HPLC blanking plug. [2] The attachment of claim 1, wherein the attachment comprises a first engagement element configured to engage a compatible second engagement element of the HPLC capillary screw head and, when engaged, to transmit the torque; and / or wherein the attachment comprises a third engagement element configured to engage a compatible fourth engagement element of the torque tool and, when engaged, to transmit the torque. [3] The attachment according to claim 2, wherein the attachment is configured to guide the HPLC capillary such that engagement between the third and fourth engagement elements is possible and / or engagement between the first and second engagement elements is possible; wherein the attachment preferably has a through-opening, e.g. a lateral opening, configured to guide the HPLC capillary such that engagement between the third and fourth engagement elements is possible and / or engagement between the first and second engagement elements is possible. [4] An attachment according to claim 3, wherein the first engagement element - has a section of the feed-through opening; - is a male or female engagement element, e.g. a male or female hexagon engagement element; and / or - has a plurality of engagement element sections, wherein the engagement element sections are arranged around the section of the through opening. [5] An attachment according to any one of claims 2-4, wherein the second engagement element is spaced from an outer periphery of the HPLC capillary screw head and / or is a female engagement element. [6] An attachment according to any one of claims 2-5, wherein the attachment extends from a proximal side having the third engagement element to a distal side having the first engagement element, and preferably wherein the first engagement element is spaced from an outer periphery of the distal side. [7] An attachment according to claim 6 when dependent on claim 3, wherein the attachment has a substantially cylindrical basic shape with a base surface, a cover surface and a jacket extending from the base surface to the cover surface, wherein the base surface corresponds to the proximal side and the cover surface corresponds to the distal side, and wherein the feedthrough opening extends from a central position on the distal side through the jacket. [8] Attachment according to one of claims 3-7, wherein the through opening - has a length of at least 10 mm; - has a bend, wherein the bend preferably has a radius of 6 mm; - has a width of at least 350 µm; - has a depth of at least half the diameter of the attachment, and optionally plus half the diameter of the capillary; and / or - in the portion of the through-opening which the first engagement element has, is formed as a slot which extends from a lateral surface of the first engagement element in the direction of the central axis of the first engagement element and optionally up to the central axis of the first engagement element and / or beyond. [9] An attachment according to any one of claims 3-8, wherein the through-opening has a portion extending through a portion of the attachment different from the first engagement element. [10] Attachment according to one of claims 2-9, wherein the third engagement element is a standardized engagement element, for example one of the following engagement elements: - a 1 / 4 inch square socket - a 1 / 4 inch external square - a 1 / 2 inch square socket - a 1 / 2 inch external square - a 3 / 8 inch square socket - a 3 / 8 inch external square - a 5 / 16 inch square socket - a 5 / 16 inch external square - a 4-14 mm hexagon socket - a 4-14 mm external hexagon - a 4-14 mm internal octagon - a 4-14 mm external octagon - a 4-14 mm internal ten-square - a 4-14 mm external ten-square - a 4-14 mm internal twelve-point - a 4-14 mm external twelve-point - External Torx (E-socket) - Internal Torx (E-socket) - a thread, preferably with one turn in the same direction as the thread of the HPLC capillary screw head; - the third engagement element is part of a blade configured to engage with a torque screwdriver handle with torque function. [11] Attachment according to one of the preceding claims, wherein the attachment, preferably in sections, has the following dimensions: - as a cylinder with a circular base and top surface: a radius of at least 3.5 mm and / or a maximum of 10 mm; a cylinder height of at least 12 mm; - as a cuboid (i.e. a right cylinder with a rectangular, e.g. square, base and top surface): a side length or diameter of the base and / or top surface of at least 7 mm and / or a maximum of 20 mm; a height of the cylinder of at least 12 mm; - as a right cylinder with a hexagonal base and top surface: a side length of the base and / or top surface of at least 3.5 mm and / or a maximum of 10 mm; a diameter of the base and / or top surface of 7 mm to 20 mm; a height of the hexagonal cylinder of at least 12 mm; and / or - as a right cylinder with octagonal base and top surface: a side length of the base and / or top surface of at least 2.9 mm and / or a maximum of 8.5 mm; a diameter of the base and / or top surface of 7 mm to 20 mm; a height of the octagonal cylinder of at least 12 mm. [12] Attachment according to one of the preceding claims with integrated torque function. [13] Set that includes: - an attachment according to one of the preceding claims; and - a compatible torque tool. [14] Torque tool with integrated attachment according to one of the preceding claims without claim 13.

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