Chromatography separation column module and chromatograph

Abstract

The present invention relates to a separation column module (1) for a chromatograph, particularly a gas chromatograph, comprising: a chromatographic separation column (2); a temperature control device (3) on the separation column (2) for generating a temporal and / or spatial temperature profile (6) along the separation column (2); and a control unit (4) connected to the temperature control device (3) and designed to electronically control the temperature control device (3), wherein the separation column (2) forms at least one turn (9) and a containment area (10) within at least one turn (9), the control unit (4) is at least partially located within the containment area (10), the separation column (2) is divided into a plurality of segments (22), each segment (22) is assigned to a respective temperature control element (23) of the temperature control device (3), and the temperature control element (23) is configured to heat and / or cool the respective assigned segment (22). Furthermore, the present invention relates to a chromatograph (29) having such a separation column module (1).

Description

Technical Field

[0001] The present invention relates to a separation column module for chromatography, particularly for gas chromatography, comprising a chromatographic separation column, a temperature control device on the separation column for generating a temporal and / or spatial temperature profile along the separation column, a control unit connected to the temperature control device and configured to electronically control the temperature control device, wherein the separation column forms at least one winding and an accommodation area within at least one winding, and the control unit is at least partially arranged within the accommodation area, relating to a separation column module.

[0002] Furthermore, the present invention relates to a chromatography, particularly a gas chromatography, comprising an injector, a detector, and an evaluation unit.

Background Art

[0003] Gas chromatography (GC) is one of the most important techniques for the separation and quantification of volatile and semi-volatile organic compounds. Gas chromatography typically comprises a system in which, after sample application, the analyte passes through a chromatographic separation column and enters a detector at the end of this separation column. When passing through the separation column, the individual components of the analyte are retained to different degrees depending on the difference in the degree of interaction with the so-called stationary phase and are thereby separated. To efficiently separate substances with different boiling points, a temperature program is often used, i.e., the separation column and the substances to be separated therein are usually subjected to a temperature gradient that rises from low to high over time in a column oven heated by circulating air.

[0004] The use of a temporally varying and spatially resolved temperature gradient is known to shorten the measurement time and simultaneously obtain a high resolution.

[0005] Gas chromatographs and corresponding methods capable of generating such temperature gradients are described, for example, by Booker, P., and J. Lepert, “Flow-Field Thermal Gradient Gas Chromatography,” Analytical Chemistry, Vol. 87, No. 17, pp. 9033–9041, 2015, or in European Patent Application Publication No. 3123165. In this case, a metal direct-resistance heated separation capillary fixed in a helical recess of a hollow cylinder is cooled by an airflow. The hollow cylinder is filled with a porous material, and as air flows through it, it creates an increasing pressure loss from the lower end to the upper end of the hollow cylinder, resulting in a corresponding decrease in the airflow flowing from the lower end to the upper end of the structure. The airflow, forced through the hollow cylinder by a fan, then flows out from an outlet along the cylindrical shell, cooling the separation capillary located therein as the pressure and flow rate decrease. This creates a negative temperature gradient along the separation column. Disadvantageously, the experimental apparatus described herein requires a large space. Furthermore, the described system can only achieve isothermal separation or separation using a temperature program that decreases monotonically along the separation path.

[0006] Contreras, JA et al., “Dynamic Thermal Gradient Gas Chromatography,” Journal of Chromatography A, 2013, Vol. 1302, pp. 143–151, also discloses a gas chromatograph and corresponding method capable of generating a temperature gradient along a separation capillary. The separation capillary is enclosed in a nickel capillary and divided into individually heatable segments. The separation capillary is inserted into an external holding device of the gas chromatograph, which includes multiple cooling fans below the separation capillary. A drawback of the described apparatus is its very large structural volume, and therefore the need for a large space in addition to the GC. Furthermore, the system lacks flexibility or is relatively expensive to maintain because the separation capillary is housed within the holding device.

[0007] Gas chromatographs are also known from U.S. Patent No. 3,146,616 and International Publication No. 2022 / 112101.

[0008] Chromatographs and methods for operating them are also described in U.S. Patent No. 3,122,014, U.S. Patent No. 3,306,347, and U.S. Patent Application Publication No. 2017 / 0234840.

[0009] U.S. Patent No. 3,035,383 also discloses a chromatograph having a helical separation column guided along a vertically supported column. A heating element, positioned on a support plate rotatable around the support column, can be displaced along the separation column. [Overview of the project] [Problems that the invention aims to solve]

[0010] In light of these descriptions, the object of the present invention is to mitigate, or even completely eliminate, the drawbacks of the prior art. Preferably, the object of the present invention is to realize the type of isolation column module described at the beginning, which is small in size and increases the overall flexibility of the system without limiting the performance of the isolation column module. [Means for solving the problem]

[0011] This objective is achieved by the separation column module described in claim 1 and the chromatograph described in claim 10.

[0012] According to the present invention, in a separation column module for the type of chromatograph described at the beginning, the separation column is divided into multiple segments, each segment is assigned to a temperature control element of a temperature control device, and the temperature control element is configured to heat and / or cool the assigned segment. A compact separation column module is created that can be used in a chromatograph or chromatography and can be replaced in a simple manner by at least one turn (i.e., a single loop of coil) and insertion of a control unit into a housing area obtained within at least one turn. The efficiency or effectiveness of the separation column is not reduced by at least one turn, but at the same time, its spatial expansion is reduced compared to, for example, a linear separation column. The space obtained within at least one turn is used by inserting the control unit into a housing area. In addition, the stability of the separation column module can be improved by connecting the separation column to the control unit or a support element of the control unit, which will be described in more detail below. The separation column module may be used in chromatographs from different manufacturers. In a preferred exemplary embodiment of the present invention, at least one winding, and therefore the containment area, has a diameter of 40 mm to 90 mm, particularly 55 mm to 70 mm. A single winding is a curve in space representing a combination of preferably circular rotation around a rotation axis and translation along the same rotation axis. The rotation around the rotation axis is at least 360°. Thus, at least one winding completely surrounds the control unit at least once. However, viewed in the direction of the rotation axis, at least one winding does not necessarily have to be circular in shape, and may, for example, be substantially elliptical, m-sided, particularly triangular or rectangular in shape. If at least one winding is m-sided, the corners may be rounded. For n windings where n is a natural number, correspondingly, at least 360° rotations around the rotation axis of the separation column are performed n times. The separation column may have, for example, a separation capillary made of fused silica, which preferably passes through a protective capillary, particularly a metal capillary.To generate at least one winding, the separation column, and if present, the protective capillary, are bent accordingly. The separation column may have an inner diameter of, for example, 0.1 mm μm to 0.750 mm. In one embodiment of the present invention, the thickness of the stationary phase in the separation column may be 0.07 μm to 0.15 μm, and in particular substantially 0.1 μm. In an exemplary embodiment of the present invention, the protective capillary may have an inner diameter of 0.4 mm to 5 mm, preferably 0.6 mm to 1.5 mm, and more preferably 0.7 mm to 1 mm. In an exemplary embodiment of the present invention, the outer diameter of the protective capillary may be 0.6 mm to 5 mm, preferably 0.8 mm to 1.7 mm, and more preferably 0.9 mm to 1.2 mm. The separation column and, if present, the protective capillary, may have a length of 0.5 m to 10 m, preferably 1 m to 5 m or 1 m to 3 m, for example substantially 1.5 m. The length of the separation column or separation capillary may be longer than the length of the protective capillary to allow connection to an injector or detector. The region of the separation column extending beyond the length of the protective capillary may be referred to as the transfer region. These transfer regions are preferably provided with separate heaters. The separation column may have any polarity and texture. For example, the separation column may be a WCOT thin-film capillary column (WCOT = wall-coated open tube) having a 95% methyl 5% phenylsiloxane coating (stationary phase). The separation column has a first end for connection to an injector and a second end for connection to a chromatograph detector. The control unit has an electrical circuit for controlling the temperature control device. The electrical circuit may have switches such as relays or transistors, especially MOSFETs, electrically connected to the temperature control device. In addition to switches, the circuit may also have further electrical or electronic components such as resistors, coils, diodes, or capacitors. Furthermore, the control unit may have a microprocessor or microcontroller on which control and / or adjustment programs are implemented for controlling or adjusting the temperature control device.A microprocessor or microcontroller can be connected to the chromatograph's process control unit via an interface, such as a BUS interface. Through this interface, the chromatograph can activate or stimulate a control unit to generate a temperature profile. In this case, a control and / or adjustment program for controlling or adjusting the temperature control unit is implemented in the chromatograph's process control unit. The temperature control unit may have one or more independent heating and / or cooling elements, such as a Peltier element or a metal or ceramic resistance heating element. The temperature control unit can be used to generate a temporal and / or spatial temperature profile along the separation column. For example, a temperature wave can be generated along the separation column. However, it is also possible to generate a static temperature gradient or a substantially constant temperature profile along the separation column. In addition, ventilation can be provided to generate the temperature profile quickly and efficiently.

[0013] In a preferred embodiment of the present invention, the separation column is provided to form a plurality of windings along a rotation axis, and the housing area extends along this rotation axis. In an exemplary embodiment of the present invention, there are at least 3, at least 4, at least 5, at least 6, at least 7, or at least 8 windings. The windings may be regularly spaced apart from each other. In other words, all windings may have the same pitch. When a plurality of windings are provided, the separation column preferably forms a helix. The housing area, in which the control unit is at least partially housed, is located within these windings. As already mentioned, n windings result in the separation column rotating at least n*360° around the rotation axis, and the windings themselves do not need to be circular, but are preferably circular.

[0014] To simplify handling, it is advantageous that the control unit is at least partially, preferably completely, located on a support element, particularly a printed circuit board. In particular, the electrical circuits of the control unit may be located on the support element. The support element is at least partially located within the housing area and is therefore at least partially surrounded by at least one winding of the isolation column. Preferably, the support element is substantially elongated. Preferably, the support element is located substantially parallel to the longitudinal axis of the housing area and / or substantially parallel to the rotation axis of the winding. Preferably, the support element has a longitudinal axis located substantially parallel to the longitudinal axis of the housing area and / or substantially parallel to the rotation axis of the winding. In one embodiment of the present invention, if the control unit has a microprocessor or microcontroller as described above, the microprocessor or microcontroller may be mounted on the support element and form part of the circuit located on the support element. Alternatively, the microprocessor or microcontroller may be provided separately from the support element, i.e., it may not be located on the support element. In this embodiment, a microprocessor or microcontroller can be connected by wires or cables to the circuitry of the control unit on the support element in order to control and / or adjust the temperature control device. The electrical connections in the electrical circuitry of the control unit on the support element, and optionally to the microprocessor or microcontroller, may be realized by wires, or, in particular, by conductive tracks, in the case of a printed circuit board as the support element. The support element is preferably substantially rectangular in shape. The maximum width of the support element is preferably less than the diameter along the cross-section of the housing area. However, the length of the support element may be longer than the length of the housing area, such that the support element protrudes upward and / or downward beyond the housing area. However, the maximum length of the support element may be shorter than the length of the housing area.

[0015] For safe handling, it is preferable that the support element is connected to the isolation column via at least one retaining element. The at least one retaining element can hold the support element and the isolation column in an appropriate position relative to each other. The retaining element may be designed, for example, as a retaining clamp, as a retaining spring, or as a latching element. If a protective capillary is provided, at least one retaining element can be connected to it. The at least one retaining element may also function as a spacer between the isolation column or protective capillary and the support element. Preferably, a plurality of retaining elements of the same type are provided. At least one retaining element may be positioned on the side edge of the support element. If a plurality of retaining elements are provided, they are preferably arranged regularly spaced apart from each other along one or more side edges. In one embodiment of the present invention, at least one retaining element may be formed by a part of a temperature control element, particularly a part of the heating element of the temperature control element. When at least one retaining element is formed by a part of a temperature control element, it may be connected, for example, to a terminal clamp on the support element which is electrically connected to a switch of a control unit.

[0016] The present invention provides that a separation column is divided into a plurality of segments, preferably at least 5 or at least 10 segments, and each segment is assigned to a respective temperature control element of a temperature control device, the temperature control element being configured to heat and / or cool the assigned segment. The segments are preferably adjacent to each other. However, the segments may also be spaced apart from each other. In one embodiment, the entire separation column is divided into segments. The temperature control elements may be, for example, Peltier elements or heating wires. The temperature control elements may at least partially or completely surround the segments assigned to them. The segments of the separation column may have, for example, lengths of 50 mm to 150 mm. If heating wires are provided as temperature control elements, they may be wrapped around the segments multiple times. In one embodiment of the present invention, the temperature control elements may be electrically connected to a control unit, in particular to each switch of the control unit, preferably via electrically insulated retaining elements. The retaining elements may also be formed by a portion of the temperature control elements, in particular by heating wires. The retaining elements may be electrically connected to terminals on a support element that can be electrically connected to a switch.

[0017] To enable individual control of each temperature control element, it is advantageous that each temperature control element is connected to a switch (preferably a transistor, particularly a MOSFET) in the control unit. The switches form part of the control unit's electrical circuit. Each assigned temperature control element can be controlled via the switch, thereby heating or cooling the segment assigned to each temperature control element. Depending on the type of switches and their electrical interconnections, a voltage, particularly a power supply voltage, can be applied to each temperature control element connected to a switch by activating the switches, particularly by activating or deactivating them.

[0018] In a preferred embodiment of the present invention, each temperature control element is provided to have a particularly wound conductive heating wire positioned around the separation column. If the separation column is surrounded by a protective capillary, particularly a metal capillary, each heating wire may be wound around the protective capillary. In particular, a copper-nickel alloy, such as CuNi44, may be used as the heating wire. The dimensions of the heating wire depend on the specific application. In one embodiment of the present invention, the heating wire of the temperature control element has a cross-sectional diameter substantially of 0.4 mm to 0.8 mm, particularly of 0.6 mm, and a length of 400 mm to 600 mm, particularly of 500 mm. In an exemplary embodiment of the present invention, the heating wire can heat a segment of the separation column to a temperature of 100°C to 350°C, preferably 100°C to 300°C.

[0019] A particularly advantageous modification of the present invention is that the control unit may be configured to control a temperature control element by pulse width modulation so that a temporal and / or spatial temperature profile can be generated along the isolation column. In particular, when a heating element is used, the converted heat can be controlled in a particularly simple manner. Pulse width modulation (PWM) can be generated using a microprocessor or microcontroller as described above. For this purpose, the microprocessor or microcontroller can actuate the switches described above.

[0020] The temperature profile is, for example, As one or more moving temperature waves along the separation column, As a spatially decomposed and preferably temporally varying temperature gradient along the separation column, As a substantially constant temperature distribution along the separation column, or It may be provided as a substantially constant temperature distribution along the separation column, which changes over time.

[0021] The temperature wave has a maximum value and has a temperature profile that rises and falls. The maximum value of the temperature wave may be, for example, 50°C to 250°C. The speed of the temperature wave may be 0.03 m / s to 0.3 m / s. The moving temperature wave can be generated by corresponding time-varying control of the temperature control element. The advantages of the moving temperature wave are as follows.

[0022] First, the gradient of the moving temperature wave is typically steeper than the spatially resolved temperature gradient along the entire separation column. This results in a narrower peak and thus better resolution.

[0023] Second, the temperature wave is preferably generated not only by a single heating and cooling system but also by a plurality of temperature control elements. As a result, the speed and steepness of the wave can be accurately controlled by changing the heating output and the heating interval of the individual segments. When a substance passes through a separation column having a negative temperature gradient, the substance peak is focused. This focusing is due to acceleration behind the higher temperature peak and deceleration in front of the lower temperature peak. When the gradient is in the form of a moving temperature wave, the substance separated along this gradient can move through the separation column at a specific temperature level, a so-called equilibrium temperature, which is substantially fixed. Staying at a specific point on the moving wave is due to acceleration occurring because the front of the peak is at a lower temperature and deceleration occurring because the rear of the peak is at a higher temperature. By appropriately selecting the speed of the temperature wave, the elution of the substance can be promoted. The described effects optimize, on the one hand, the resolution or separation of the analyte and, on the other hand, the measurement time.

[0024] A temperature wave can move from a first end of the separation column to a second end of the separation column, or in the reverse direction (from the second end of the separation column to the first end of the separation column). A spatially resolved temperature gradient preferably increases monotonically toward a global maximum value which may be, for example, 250°C, and remains at least spatially fixed; that is, in contrast to a temperature wave, the temperature gradient does not move along the separation column. The temperature gradient may also be multi-stage and may have different increasing gradients. In one embodiment, the temperature gradient may change over time during the separation process. In particular, the slope of the temperature gradient can be adjusted. In a preferred embodiment of the present invention, the temperature gradient extends along the entire separation column. The gradient can be positive or negative, that is, it can rise or fall from a first end of the separation column to a second end of the separation column. A substantially constant temperature distribution along the separation column does not have a temperature gradient. The latter may be referred to as an isothermal temperature profile. The temperature of the temperature profile may be, for example, up to 250°C. A substantially constant temperature distribution along the separation column preferably extends substantially along the entire separation column. Isothermal separation occurs when the substantially constant temperature distribution along the separation column is also constant in time during the separation process. In one embodiment of the present invention, the substantially constant temperature distribution along the separation column may change in time during the separation process. Thus, the temperature level of the constant temperature distribution along the separation column can be changed in time. This corresponds to temperature-programmed separation, which is commonly used in conventional gas chromatographs. The temperature of the temperature profile that changes in time may be, for example, up to 250°C. Similar to isothermal systems, temperature-programmed separation has a uniform temperature along the separation column, so the temperature is not a function of position. Unlike isothermal separation, the temperature of the separation column changes or increases during the separation process, usually by heating in the air bath in the column furnace of a GC. As a result, analytes containing different volatile substances can be separated efficiently in time.

[0025] The object stated at the beginning is also achieved by a chromatograph, in particular a gas chromatograph, having an injector, a detector and optionally an evaluation unit, in which a separation column module of the above type is used. In a gas chromatograph, a mobile phase and a separation column having a suitable stationary phase are used. As the mobile phase, an inert gas such as nitrogen or helium or hydrogen may be used. As the stationary phase, for example, 5% phenyl 95% methylpolysiloxane may be used. Examples of analytes include hydrocarbons from the petrochemical industry or decomposition products of the electrolyte of a lithium-ion battery. As the injector, preferably a split / splitless injector is used. The detector may be, for example, a FID detector. The pressure in the separation column is preferably 50 kPa to 400 kPa.

[0026] Also disclosed is a chromatography method, in particular a gas chromatography method, using the described chromatograph. The sample is introduced into the separation column via the injector, separated into individual compounds and analyzed by the detector.

[0027] The present invention can also be described with reference to the following embodiments.

[0028] Embodiment 1: A separation column module for a chromatograph, in particular for a gas chromatograph, comprising a chromatographic separation column, a temperature control device on the separation column for generating a temporal and / or spatial temperature profile along the separation column, a control unit connected to the temperature control device and designed to electronically control the temperature control device, where the separation column forms at least one winding and an accommodation region within the at least one winding, and the control unit is at least partially arranged within the accommodation region, the separation column module.

[0029] Embodiment 2: The separation column module according to Embodiment 1, wherein the separation column forms multiple windings along the axis of rotation, and the containment area extends along the axis of rotation.

[0030] Embodiment 3: The isolation column module according to Embodiment 1 or Embodiment 2, wherein the control unit is at least partially, preferably completely, located on a support element, particularly on a printed circuit board.

[0031] Embodiment 4: The isolation column module according to Embodiment 3, wherein the support element is connected to the isolation column via at least one retaining element.

[0032] Embodiment 5: A separation column module according to any one of Embodiments 1 to 4, wherein the separation column is divided into a plurality of segments, preferably at least 5 or at least 10 segments, and each segment is assigned to a respective temperature control element of a temperature control device, and the temperature control element is configured to heat and / or cool the respective assigned segment.

[0033] Embodiment 6: The isolation column module according to Embodiment 5, wherein each temperature control element is connected to a switch, preferably a transistor, in particular a MOSFET, of the control unit.

[0034] Embodiment 7: The separation column module according to Embodiment 5 or Embodiment 6, wherein the temperature control element each has a particularly wrapped conductive heating wire positioned around the separation column.

[0035] Embodiment 8: A separation column module according to any one of Embodiments 5 to 7, wherein a control unit is configured to control a temperature control element by pulse width modulation so that a temporal and / or spatial temperature profile can be generated along the separation column.

[0036] Embodiment 9: The temperature profile is, As one or more moving temperature waves along the separation column, As a spatially decomposed and preferably temporally varying temperature gradient along the separation column, As a substantially constant temperature distribution along the separation column, or A separation column module according to any of Embodiments 1 to 8, provided as a substantially constant temperature distribution along the separation column that changes over time.

[0037] Embodiment 10: A chromatograph, more particularly a gas chromatograph, comprising an injector, a detector, and optionally an evaluation unit, wherein a separation column module described in any one of Embodiments 1 to 9 is used in the chromatograph.

[0038] The present invention will be described in more detail below with reference to exemplary embodiments, but will not be limited thereto. [Brief explanation of the drawing]

[0039] [Figure 1] A schematic diagram of the isolation column module is shown. [Figure 2] This is a schematic front view of the isolation column module. [Figure 3] This is a schematic side view of the isolation column module. [Figure 4] This is a schematic top view of the isolation column module. [Figure 5] A schematic diagram of the separation column module is shown. [Figure 6] A schematic diagram of the temperature control element on the isolation column within the electrical circuit is shown. [Figure 7] A schematic diagram of the temperature control element on a linear separation column is shown. [Figure 8] This is a temperature profile along the separation column. [Figure 9] This is a block diagram of a chromatograph. [Figure 10] This is an example of a chromatogram. [Modes for carrying out the invention]

[0040] Figure 1 shows a separation column module 1 that can be used in a chromatograph 29 (see Figure 9). The separation column module 1 comprises a chromatographic separation column 2 in a metal protective capillary 5, a temperature control device 3 on the separation column 2, and a control unit 4 for controlling the temperature control device 3. For electrical insulation, the protective capillary 5 is surrounded by an insulating layer 53, preferably a polyimide layer. The inner diameter of the protective capillary 5, in which the separation column 2 is placed, is approximately 0.8 mm. The inner diameter of the separation column 2 itself is 0.1 mm. Using the temperature control device 3, temporal and / or spatial temperature profiles 6, such as a moving temperature wave 7a (see Figure 8), can be generated along the separation column 2. In this context, "along the separation column 2" also means along the protective capillary 5. Therefore, the temperature control device 3 is controlled by the control unit 4 according to a setpoint that may be specified by the process control device 52 (see Figure 9) of the chromatograph 29.

[0041] As can be seen from Figure 1, the separation column 2 has multiple windings 9 along a virtual axis of rotation 8, thereby forming a substantially cylindrical housing area 10 between the windings 9 in which the control unit 4 is housed. The outer circumference 11 of the housing area 10 (see Figure 4) is defined by the windings 9. Thus, the width 12 of the housing area 10 corresponds to the distance between the windings 9 along a virtual transverse axis 13 positioned perpendicular to the axis of rotation 8. The height 14 of the housing area 10 corresponds to the longitudinal range of the entire winding 9 along the axis of rotation 8, projected perpendicularly onto the axis of rotation 8. The windings 9 trace a curve corresponding to a combination of circular rotation around the axis of rotation 8 and translation along the axis of rotation 8. The pitch h, which is the distance between each pair of windings 9 positioned vertically, i.e., adjacent windings, is preferably substantially the same for all adjacent windings 9. Thus, the shape of the separation column 2 represents a helix 15.

[0042] In the illustrated embodiment, the control unit 4 is positioned on a support element 16 in the form of a printed circuit board 17. The printed circuit board 17 has a substantially rectangular basic structure and is positioned within a housing area 10 in a winding 9. In other words, the winding 9 surrounds the support element 16. This arrangement significantly reduces the overall volume of the isolation column module 1 compared to the prior art. A portion of the support element 16 protrudes beyond the housing area 10 into a lower area 18, which can be used for handling the isolation column module 1.

[0043] Figures 2 and 3 show a front view and a side view of the separation column module 1. From Figures 2 and 3, it can be seen that the support element 16 is connected to the separation column 2 via a plurality of retaining elements 19. The retaining elements 19 are positioned on the side edges 20 of the support element 16. The retaining elements 19 are designed, for example, as retaining clamps 21. Figure 4 shows a top view of the separation column module 1, and the retaining elements 19 can also be seen.

[0044] Figure 5 schematically shows a detailed view of the separation column module. The separation column 2, or the surrounding protective capillary 5, is divided into a plurality of segments 22, each of which is wound with a temperature control element 23 in the form of a heating wire 24. In Figure 5, the segments 22 are demarcated by dashed lines. In the illustrated example, the heating wire 24 is wound directly around the protective capillary 5 surrounded by an insulating layer 53. Thus, each segment 22 is assigned its own temperature control element 23. Each assigned segment 22 can be heated using the heating wire 24, whose end is connected to the control unit 4 or electrical ground 50 (see also Figure 6). Figure 7 shows this in a magnified view, using a linear separation column 2 for clarity. In one embodiment of the present invention, there are 14 segments 22, each about 10 cm long. For example, a CuNi44 alloy with a cross-sectional diameter of substantially 0.6 mm and a length of about 500 mm may be used as the heating wire 24. The resistivity of such a heating element 24 is substantially 1.73 Ω / m. The ends 24a of the heating element 24 may be wired to each switch 25, for example, in or within the holding element 19, which will be described in more detail below. However, it is also possible that the holding element 19 is formed by the ends 24a of the heating element 24, or that the heating element 24 is electrically connected to the switch 25 via the holding element 19. The holding element 19 or the ends 24a of the heating element 24 can be connected, for example, to terminals 54 on the support element 16, in particular to printed circuit terminals, which are electrically connected to the switch 25. In this way, each temperature control element 23 can be electrically connected to the switch 25, which will be described in more detail below.

[0045] Figure 6 shows the interconnection of the temperature control elements 23. Each temperature control element 23 is connected to the electrical switch 25 and electrical ground 50 of the control unit 4. The switch 25 forms the circuit 51 of the control unit 4. In the illustrated embodiment, the switch 25 is embodied as a MOSFET 26 and is operated by applying a control voltage to its gate. By operating the switch 25, a voltage U can be supplied to the heating element 24 corresponding to the temperature control element 23, thereby allowing the heating element 24 to operate according to the law P=U 2 Heat is generated by resistive losses according to / R, where P is the power, U is the applied voltage, and R is the resistance of each heating element 24. In the illustrated exemplary embodiment, switches 25 switch the substantial voltage U on each heating element 24 by activating them, i.e., by applying a control voltage to the gate (normally open circuit). However, normally closed circuits with corresponding switches are also conceivable. To adjust the heating output, in the illustrated embodiment, switches 25 are provided to be driven via PWM 27 (PWM = pulse width modulation) of the control voltage. In another embodiment, the PWM can be generated by a microcontroller 28 located on a support element 16 and representing part of the circuit 51 of a control unit 4 on the support element. The heating output of the heating elements can be adjusted by selecting the duty cycles D1, D2, D3 of the PWM.

[0046] A control and / or adjustment program for controlling and / or adjusting the temperature control device 3 can be implemented in the microcontroller 28. Using the control and / or adjustment program, a temporal and / or spatial temperature profile 6 can be generated along the separation column (see Figure 8). For example, one or more moving temperature waves 7a may be generated to facilitate the separation process in the separation column 2. However, it is also possible to generate a temperature gradient 7b along the separation column 2, which is spatially fixed. The illustrated temperature gradient 7b preferably extends substantially along the entire separation column 2. The temperature gradient 7b may change in time during the separation process, as shown by the dashed line. Figure 8 also shows a substantially constant temperature distribution 7c that extends substantially along the entire separation column 2 (isothermal separation). The substantially constant temperature distribution along the separation column 2 can change in time during the separation process (temperature program separation program), as also shown by the dashed line and reference numeral 7d. T represents temperature, and x represents the position coordinate along the separation column 2. For clarity, separation column 2 is shown as a straight line in the upper region of Figure 8, but according to the present invention, it is wound.

[0047] Figure 9 shows a chromatograph 29, particularly a gas chromatograph 30, equipped with an injector 31, a detector 32, an evaluation unit 33, and a separation column module 1.

[0048] Chromatography using the separation column module 1 according to the present invention is described below. Baseline separation of C8 to C20 was achieved in approximately 5 seconds. Please refer to the chromatogram in Figure 10. The horizontal axis of the figure represents the retention time t in minutes. RThe graph shows the results. The vertical axis represents intensity I. In this separation, C8-C20 n-alkane solutions (each approximately 40 mg / l in n-hexane, Sigma-Aldrich, catalog number Supelco04070) were used and applied to separation column 2 in liquid form by an autosampler, with a volume of 1 μl and a split ratio of 200:1. The injector 31 (250°C), carrier gas flow (helium, 0.5 ml / min), and detector 32 (FID) were controlled by an Agilent 6890N gas chromatograph. The first and last approximately 0.5 m of separation column 2 functioned as transfer capillaries, leading to the system's injector 31 or detector 32, and were individually heated to 140°C.

Claims

1. A separation column module (1) for chromatography, particularly for gas chromatography, Chromatographic separation column (2), A temperature control device (3) on the separation column (2) for generating a temporal and / or spatial temperature profile (6) along the separation column (2), A separation column module (1) comprising a control unit (4) connected to the temperature control device (3) and designed to electronically control the temperature control device (3), wherein the separation column (2) forms at least one winding (9) and a housing area (10) within the at least one winding (9), the control unit (4) is at least partially located within the housing area (10), the separation column (2) is divided into a plurality of segments (22), each segment (22) is assigned to a respective temperature control element (23) of the temperature control device (3), and the temperature control element (23) is configured to heat and / or cool the respective assigned segments (22).

2. The separation column module (1) according to claim 1, characterized in that the separation column (2) forms a plurality of windings (9) along the rotation axis (8), and the containment region (10) extends along this rotation axis (8).

3. The separation column module (1) according to claim 1 or claim 2, characterized in that the control unit (4) is at least partially, preferably completely, disposed on the support element (16), particularly on the printed circuit board (17).

4. The separation column module (1) according to claim 3, characterized in that the support element (16) is connected to the separation column (2) via at least one retaining element (19).

5. The separation column module (1) according to any one of claims 1 to 4, characterized in that the separation column (2) is divided into at least 5 or at least 10 segments (22).

6. The separation column module (1) according to claim 5, characterized in that each temperature control element (23) is connected to each switch (25), preferably a transistor, particularly a MOSFET (26), of the control unit (4).

7. The separation column module (1) according to claim 5 or 6, characterized in that each of the temperature control elements (23) has a particularly wound conductive heating wire (24) arranged around the separation column (2).

8. The separation column module (1) according to any one of claims 5 to 7, characterized in that the control unit (4) is configured to control the temperature control element (23) by pulse width modulation so that the temporal and / or spatial temperature profile (6) can be generated along the separation column (2).

9. The temperature profile (6) is As one or more moving temperature waves (7a) along the separation column (2), As a spatially decomposed and preferably temporally changing temperature gradient (7b) along the separation column, As a substantially constant temperature distribution (7c) along the separation column (2), or The separation column module (1) according to any one of claims 1 to 8, characterized in that it is provided as a substantially constant temperature distribution (7d) along the separation column that changes over time.

10. A chromatograph (29), more particularly a gas chromatograph (30), comprising an injector (31), a detector (32), and optionally an evaluation unit (33), wherein a separation column module (1) according to any one of claims 1 to 9 is used in the chromatograph (29).

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