AUTOMATED SAMPLING

Description

[0001] The present invention relates to a device for automated sampling from containers that may be under high pressure. This is achieved by a special design with multiple multiport valves. The invention also relates to a method for automated sampling using the device according to the invention.

[0002] In order to analyze chemical reactions or their progression, it is often necessary to take samples from the reaction vessel or other containers within the reaction system or technical facility. The sample is therefore the liquid solution present in the reaction vessel or other container which corresponds or should correspond to the current reaction state. Sampling is therefore usually carried out under the then prevailing operating conditions or the conditions in the container in question, such as pressure and temperature. If these operating conditions can be described as mild, i.e. if there is a rather moderate pressure and / or a moderate temperature, for example, taking samples is relatively easy to implement and can, for example, be done manually. However, automated sampling systems are also known in the state of the art which can be used to take samples under relatively mild conditions.

[0003] However, if the reaction conditions are more drastic, sampling is not so easy. One example is reactions that take place under high gas pressure, as is the case in autoclaves or in certain reactions such as hydroformylation. High gas pressure here refers to the pressure of a gassed liquid. Manual sampling is still possible in these cases, but this is disadvantageous for several reasons. Reproducibility is generally poor, time resolution is low, and a high level of personnel deployment is required. Quite apart from safety precautions, manual sampling under drastic reaction conditions, especially high pressure, is very time-consuming. Automated systems that can take samples even at high pressure are hardly known or have other disadvantages. Cross-contamination is particularly likely to cause problems here.

[0004] There is therefore still a need for devices for the automatic, time-controlled sampling and storage of samples from reaction vessels or other containers that may be subjected to elevated pressures of up to 483 bar and temperatures of up to 150°C. Another task was to provide a method for taking samples under correspondingly harsh conditions.

[0005] The underlying object of the present invention could be achieved by the device according to claim 1 and the method according to claim 11. Preferred embodiments are specified in the dependent claims.

[0006] The device according to the invention is a device for the automated sampling of a liquid sample from a container in which a pressure of at least 20 bar, preferably of at least 50 bar, further preferably of at least 100 bar, particularly preferably of at least 150 bar can be present, the device comprising the following: a sample circuit comprising a multi-port valve (1) with at least 6 ports, an inlet line, an outlet line and a sample loop, wherein a liquid sample of the solution present in the container can be taken via the sample circuit; a solvent circuit comprising a storage container for the solvent, a second multi-port valve (2) with at least 6 ports, a pump, an inlet line, an outlet line and a solvent loop, wherein solvent for diluting the sample can be added via the solvent circuit; one or more sample vessels into which orinto which the liquid sample, preferably diluted with the solvent, can be fed; a sample distribution unit comprising a third multiport valve (3) with at least 3 ports and at least one line connected to the one or more sample vessels, via which line the sample taken from the container can be fed into the at least one sample vessel; a pressure regulation unit with which the samples can be brought to ambient pressure, wherein the pressure regulation unit comprises a further multiport valve (22) with a braking capillary and wherein the multiport valve (22) is arranged between the multiport valve (1) and the multiport valve (3); and an inert gas circuit in which an inert gas is present, wherein the inert gas circuit comprises at least one valve, an inlet line, an outlet line and lines via which all of the existing multiport valves are connected to one another.

[0007] The device according to the invention has the advantage that liquid samples can also be taken at high pressure. Pressure in the sense of the present invention and thus also in the sense of the claims means a gas pressure. Any pressure specified is understood to be an overpressure above the ambient pressure (approx. 1 bar). The liquid samples taken are, if pressure is present, gassed liquids. The sample loop can be repeatedly filled or flushed with sample. If the sample is to be taken, the valve position of the first multiport valve (1) can be changed so that the sample loop is no longer connected to the container from which the sample is taken. This makes it possible to apply a different pressure to the sample loop and no longer require the (high) pressure prevailing in the container from which the sample is taken.

[0008] A conduit, as used herein, refers to a suitable hollow body through which gases and liquids can be transported. Examples include hoses or tubes made of plastic or metal. Such conduits are commercially available in a wide variety of colors, shapes, and materials. Depending on the liquid to be sampled, a specialist can select suitable conduits, hoses, or tubes.

[0009] The container from which the sample is taken can be any container containing a liquid to be analyzed. Suitable containers are known to those skilled in the art. In a preferred embodiment, the container is a reactor in which a chemical reaction is taking place or has taken place. Samples can then be taken during the reaction, and the course of the reaction can be analyzed.

[0010] According to the invention, it is preferred if the sample distribution unit of the device described here comprises an additional multiport valve (4) with at least 6 ports. This multiport valve (4) is then the fourth multiport valve (4) overall. If such a fourth multiport valve (4) is present in the sample distribution unit of the device according to the invention, this multiport valve (4) is also connected to the inert gas circuit. The multiport valve (4) is also connected to the sample vessel(s) via at least one line. These lines represent, in particular, the drain line of the one or more sample vessels, i.e., the sample can be conveyed out of the sample vessels via these lines. The at least one line of the sample distribution unit, which is connected to the one or more sample vessels via the multiport valve (3), then functions as the inlet line, via which the sample vessel can be filled with sample.

[0011] The device according to the invention allows sampling from containers in which a pressure of at least 20 bar, preferably of at least 50 bar, further preferably of at least 100 bar, particularly preferably of at least 150 bar exists. Of course, the device can also be used to take samples from a container that has a pressure lower than 20 bar. The upper pressure limit is determined by the properties of the devices and apparatus used. Within the scope of the present invention, it is preferred that the pressure in the container from which the sample is taken is a maximum of 500 bar, preferably a maximum of 490 bar, particularly preferably a maximum of 480 bar.

[0012] Depending on the pressure in the container from which the sample is to be taken, it may be necessary to bring the sample to ambient pressure (approx. 1 bar). If the container is already at ambient pressure, this is of course not necessary. Normal pressure relief can be achieved quite easily downstream of the sample loop of the multiport valve (1), for example via a valve. Technically, it is therefore fundamentally quite easy to release the pressure. Especially when samples are taken from containers that are under high pressure, problems such as foam formation or the release of part of the sample can occur. Sampling is then still possible, but disadvantageous. Within the scope of the present invention, the device according to the invention therefore has a pressure regulation unit with which the samples can be brought to ambient pressure in a targeted manner.According to the invention, regulation by releasing the pressure is only necessary when a sample is taken from a container that has a pressure higher than the ambient pressure. The pressure regulation unit enables the pressure of the sample to be released slowly without leading to a partial loss of the sample or foam formation. The pressure regulation unit comprises an additional multiport valve (22) with a braking capillary. The multiport valve is arranged between the multiport valve (1) and the multiport valve (3). There is therefore a line from the multiport valve (1) to the multiport valve (22) and a line from the multiport valve (22) to the multiport valve (3). The braking capillary has, in particular, a suitably narrow diameter to allow the pressure to be released slowly enough. In this state, the multiport valve can have at least two positions.In position I of the multiport valve, the lines from the multiport valve (1) and the multiport valve (3) are connected via the multiport valve (22) in such a way that the brake capillary is not passed through. This can be the case, for example, during rinsing processes or in the basic position. In position II of the multiport valve (22), the lines from the multiport valve (1) and the multiport valve (3) are connected via the multiport valve (22) in such a way that the brake capillary is passed through and the pressure from the sample can be released in a controlled manner.

[0013] In a further preferred embodiment, the multiport valve (22) with the braking capillary additionally has a supply loop for inert gas, which advantageously has a high pressure of more than 100 bar. In this embodiment, the multiport valve (22) has at least two positions. In the first position, the incoming sample is passed through the braking capillary (22) and can thus degas. From there, the sample reaches the sample vessel via the third multiport valve (3). Meanwhile, the supply loop is filled with inert gas at a high pressure of at least 100 bar. In the second position, the line through which the sample arrives at the multiport valve (22) is switched to the line to the third multiport valve (3). A sample, inert gas, or solvent can then pass through unhindered. The supply loop is switched to the braking capillary in the second position of the multiport valve (22).This removes sample residues from the brake capillary to prevent cross-contamination. The inert gas is released into the exhaust gas after passing through the brake capillary.

[0014] With regard to the temperature that can be present in the containers or during sampling, the device according to the invention is limited only by the properties of the equipment, valves, or lines used. The sample properties can also represent a limit for the maximum temperature. For example, it may be advantageous if the boiling temperature of the sample is not exceeded during decompression. Nevertheless, it is fundamentally possible for samples to be taken with the device according to the invention even at temperatures > 100 °C.

[0015] The following describes the multiport valves (1, 2, 3, 4) and how the ports are connected to the respective lines, loops, and vessels. All multiport valves have at least six ports, although additional ports may be present to perform additional functions. The port connections described here are a preferred basic design, but can also be varied to some extent.

[0016] According to the present invention, it is preferred if two ports of the first multiport valve (1) are connected via two interfaces to the container from which the samples are to be taken, ie an inlet and an outlet of the container, two ports to the sample loop and two ports to the lines of the inert gas circuit.

[0017] With regard to the second multiport valve (2), it is preferred if two ports of the multiport valve (2) are connected to the storage container for the solvent, ie an inlet and an outlet, two ports are connected to the solvent loop and two ports are connected to the lines of the inert gas circuit.

[0018] In particular, the third and fourth multiport valves (3, 4) may have more than three ports, depending on the number of sample vessels. It is preferred if two ports of the third multiport valve (3) are connected to the lines of the inert gas circuit, and the other port(s) are connected to the at least one sample vessel. The number of ports is therefore variable depending on the number of sample vessels. In a preferred embodiment, one port is connected to each sample vessel. In an embodiment with six ports in the third multiport valve (3), for example, a maximum of four sample vessels are present; with seven ports in the third multiport valve (3), a maximum of five sample vessels are present.

[0019] If a fourth multiport valve (4) is present, preferably two ports of the multiport valve (4) are connected to the lines of the inert gas circuit and the other ports are connected to the at least one sample vessel, in particular to the outlet of the at least one sample vessel. It is preferred that the multiport valves (3) and (4) have the same number of ports. The connection of the ports depends on the number of sample vessels and the connections of the sample vessels to the third multiport valve (3). The connections of the fourth multiport valve (4) to the sample vessel(s) preferably correspond to the connections of the third multiport valve (3) to the sample vessel(s), with the difference that the ports of the fourth multiport valve (4) are connected to the outlet of the sample vessel(s), while the ports of the third multiport valve (3) are connected to the inlet of the sample vessel(s).This has the overall advantage that the number of sample vessels is variable and can be adapted to the specific needs of each sampling application. It may be preferable for the multiport valves (3) and (4) to switch in parallel, with the respective input port of one multiport valve corresponding to the output port of the other multiport valve. However, it is also possible for both multiport valves (3, 4) to switch independently of each other.

[0020] In a particularly preferred embodiment of the present invention, the third multiport valve (3) and / or the fourth multiport valve (4) in the sample distribution unit each have a central port. Such a central port is a common port to which all other ports can be connected. It is then preferred that the third multiport valve (3) and / or the fourth multiport valve (4) have a central port that can each be switched to the at least two other ports.

[0021] For sampling, the multiport valves can be set to different valve positions. This and the valve positions will be explained in more detail below. In a preferred embodiment of the present invention, the multiport valve (1) can be set to at least two valve positions (I and II), whereby in position I, the two ports connected to the container via the interfaces are each linked to a port connected to the sample loop, so that the liquid sample of the solution present in the container is passed via the inlet interface through the sample loop and back to the container via the outlet interface, thereby filling the sample loop with sample; and in position II, the two ports connected to the container via the interfaces are linked to one another, so that the solution is passed directly back to the container without passing through the sample loop, and the two ports connected to the sample loop are each linked to a port connected to the lines of the inert gas circuit, so that the sample present in the sample loop can be passed via the inert gas circuit to the sample distribution unit and from there to at least one sample vessel.

[0022] In position I, the sample loop is filled with the liquid sample. In position II, the connection between the sample loop and the container is disconnected and a connection to the inert gas circuit is established, allowing the sample to be passed on to the sample vessel(s). Because the sample loop is also pressure-technically decoupled from the container in position II, the desired automated sampling is possible even at high pressure in the container. It goes without saying that position I must always be selected before position II in order to fill the sample loop with sample. Otherwise, sampling would not be possible.

[0023] A similar approach is also preferred for the second multiport valve (2). In a preferred embodiment of the present invention, the multiport valve (2) can be set to at least two valve positions (I and II), whereby in position I, the two ports connected to the storage tank are each linked to a port connected to the solvent loop, so that the solvent is pumped from the storage tank via the solvent loop back to the storage tank, thereby filling the solvent loop with solvent; and in position II, the two ports connected to the storage tank are linked to each other, so that the solvent is pumped from the storage tank directly back to the storage tank without passing through the solvent loop, and the two ports connected to the solvent loop are each linked to a port connected to the lines of the inert gas circuit, so that the solvent present in the solvent loop can be pumped to the multiport valve (1) via the inert gas circuit.

[0024] In a preferred embodiment, the two multiport valves (1) and (2) can be controlled individually, i.e., the respective position I or II can be set independently of the position of the other multiport valve. This basically results in two possibilities. The first possibility is that the solvent is mixed with the sample present in the sample loop, fed to the sample distribution unit, and from there to at least one sample vessel. In this case, both multiport valves (1) and (2) are in position II.

[0025] The second possibility is to run through the device according to the invention or the sample loop and all other lines without a sample, whereby on the one hand the device according to the invention can be rinsed, for example in order to avoid cross-contamination, and on the other hand a blank sample can be taken. In this case, there is no need to take a new sample, i.e. the multiport valve (1) remains in position I and only the multiport valve (2) is in position II. In this context, it is possible for the solvent not to be passed through a sample vessel during rinsing, but to be led directly to the outlet. This can prevent contamination of the sample vessel. If a blank sample is taken, this is of course led into a sample vessel.

[0026] It is further preferred that the second multiport valve (2) is connected to the inlet line of the inert gas circuit. This means that the inert gas is first fed to the multiport valve (2) and then finally to the first multiport valve. Such a solvent circuit has the advantage that the sample does not first have to be displaced from the sample loop by the inert gas; instead, the solvent acts as a buffer between the inert gas and the sample and dilutes the sample. The solvent, or the possibility of feeding solvent through the sample loop, also has the further advantage that the sample loop can be cleaned. This prevents cross-contamination between successive samples.

[0027] Any suitable pump can be used for the solvent circuit. Suitable pumps are known to those skilled in the art. According to the invention, the pump for the solvent circuit is preferably an HPLC pump, a diaphragm pump, a centrifugal pump, a gear pump, or a gerotor pump.

[0028] The inert gas circuit of the device according to the invention contains an inert gas. Any gas that is inert to the sample material can be used as the inert gas. A reaction between the sample and the inert gas must not occur to avoid falsifying the sample. The inert gas is preferably a known inert gas, in particular nitrogen, argon, or helium. Nitrogen is particularly preferred. The inert gas can be supplied to the inert gas circuit from a suitable source, for example from a gas cylinder or from inert gas lines available at the location of the device. The inert gas is supplied and metered into the inert gas circuit via the existing valve. This valve of the inert gas circuit is preferably a solenoid valve or a pneumatic valve, but it is more preferably a solenoid valve. These valves enable precise metering and can preferably be controlled automatically.

[0029] The inert gas circuit has a residual outlet through which samples and / or solvents and / or the inert gas are removed from the device. However, there can also be a collection facility in which samples and solvents are collected before being disposed of. A suitable waste container would be conceivable here. However, it is also conceivable that, if the sample and solvent do not contain any hazardous substances, they are disposed of directly into the sewer system without a waste container. It would also be possible for the sample to be returned to the container from which it was taken. In this case, however, a solvent should be used that is already present in this container, for example as a solvent or as a reactant or product of a chemical reaction.

[0030] The excess inert gas generated during sampling and / or subsequent purging can preferably be channeled into the exhaust gas via the waste container. For this purpose, the waste container can be depressurized via an inertized exhaust line located in the inert gas circuit. The solvent storage tank can also have such an exhaust line to channel or depressurize any gases generated there, including, for example, residual inert gas, into the exhaust gas.

[0031] In a particularly preferred embodiment of the present invention, the inert gas circuit, via which all existing multiport valves are connected to each other, comprises the following lines: a line leading from an inert gas source to the second multiport valve (2) via a valve with which the inert gas supply can be controlled; a line leading from the second multiport valve (2) to the first multiport valve (1); a line leading from the first multiport valve (1) to the further multiport valve (22); a line leading from the further multiport valve (22) to the third multiport valve (3), preferably to the middle port of the third multiport valve (3); at least one line, preferably two or more lines leading from the third multiport valve (3) to the at least one or more sample vessels;a line leading from each sample vessel to the residual outlet, preferably a line leading from each sample vessel to one of the ports of the fourth multi-port valve (4), wherein these ports can each be switched to an additional port, and a line leading from the additional port of the fourth multi-port valve (4) to the residual outlet;

[0032] With regard to the sample vessels, at least one sample vessel should be present within the scope of the present invention. However, for certain applications it may be advantageous if the device according to the invention comprises two or more sample vessels. If two or more sample vessels are present, several samples can be taken automatically one after the other at very short intervals, which would be difficult to do manually. This is particularly advantageous when investigating / sampling very fast reaction kinetics. Suitable sample vessels are generally known to the person skilled in the art. Examples are simple plastic or glass vessels, for example corresponding vials, tubes or cuvettes. According to the present invention, the sample vessels are preferably vials, particularly preferably glass vials, which can be used in gas chromatography analysis. The sample vessel(s) are preferably each sealed with a septum.A suitable septum is, for example, one that can be pierced by a cannula while remaining sufficiently mechanically and chemically stable. Such a cannula, which pierces the septum, can then represent the inlet and outlet. Preferably, at least two cannulas are present, one for the inlet and one for the outlet.

[0033] The sample vessel(s) can be arranged in a holder, for example a sample block. This makes handling and storage of the sample vessels easier. To increase safety, the sample vessels can also each be arranged in a beaker, with the beaker serving as burst protection. A collecting tray can also be arranged below the holder or below the sample block in order to collect liquid leaking from the sample vessels. Corresponding collecting trays can also be arranged below the storage container and / or the waste container. Unnecessary and potentially harmful soiling and contamination of the working environment of the device according to the invention with the substances used, i.e. solvent and sample, can thus be avoided.

[0034] A further subject of the present invention is a method for automatically sampling a liquid sample from a container in which a pressure of at least 20 bar, preferably of at least 50 bar, further preferably of at least 100 bar, particularly preferably of at least 150 bar can be present, using the device according to the invention and described above, wherein a) a liquid sample is taken from the container and temporarily stored in the sample loop of the sample circuit; b) a solvent is taken from the storage container and temporarily stored in the solvent loop of the solvent circuit; c) an inert gas is present in the lines of the inert gas circuit; and d) to take the sample, the position of the existing valve and the multiport valves is changed so that the solvent temporarily stored in the solvent loop is guided by the inert gas to the sample temporarily stored in the sample loop and the sample diluted with the solvent is transported from there via the sample distribution unit to one or more sample vessels.

[0035] If the device according to the invention is to be flushed, step a) is omitted, meaning no sample is temporarily stored in the sample loop. It is also conceivable, in principle, to take the sample without solvent. In this case, the sample is forced from the sample loop to the sample vessel by the inert gas. In this case, step b) can be omitted. Step d) then changes accordingly.

[0036] The valve here is the inert gas circuit valve. The multiport valves are the existing multiport valves (1), (2), and (3). The position of the inert gas circuit valve(s) and multiport valves (1), (2), and (3) have already been discussed with regard to the device. The multiport valves (1) and (2) can preferably be set to position I and position II. The inert gas circuit valve(s) can preferably be open or closed. The third multiport valve (3) can assume various positions depending on the number of sample vessels. A specific position of the third multiport valve (3) is the one in which the multiport valve (3) is switched directly to the residual outlet and is not directed to the sample vessel.

[0037] The basic position of the valves and the multiport valves of the device according to the invention refers to the point in time in the process before a (new) sample is taken. The basic position is characterized by the fact that the at least one valve of the inert gas circuit is closed; the first multiport valve (1) is set to position I; the second multiport valve (2) is set to position I; the multiport valve (22) is set to position I, wherein the line from the multiport valve (1) and to the multiport valve (3) are connected to one another via the multiport valve (22) in such a way that the braking capillary is not passed through; the middle port of the third multiport valve (3) is switched to the port that leads to the residual outlet or, if present, to the fourth multiport valve (4); and the port of the multiport valve (4), if present, that is connected to the third multiport valve (3), is switched to the middle port of the fourth multiport valve, the middle port leading to the residual outlet.

[0038] It may be preferable if the solvent circuit pump is not delivering, provided all existing valves and multiport valves are in the home position. Starting from this home position, the positions of the valves and multiport valves must be changed in order to take a sample from the container according to the invention. In principle, it is possible to change the position of all valves and multiport valves at once. However, within the scope of the present invention, it is preferred if the position of the valves and multiport valves is changed successively.

[0039] In a preferred embodiment, the inert gas circuit valve is opened first. The other multiport valves are then switched over. According to the present method, the above-described basic position of the existing valves (including multiport valves) is changed according to the following variable sequence to take the sample: 1) the at least one valve of the inert gas circuit is opened, preferably for at least 5 seconds and up to 120 seconds, particularly preferably for up to 90 seconds; 2) the middle port of the third multiport valve (3) is switched to the port leading to a sample vessel in order to flush the sample vessel with inert gas, and optionally a port of the fourth multiport valve (4) coming from the sample vessel is switched to the middle port of the fourth multiport valve (4) in the direction of the residual outlet; 3) the at least one valve of the inert gas circuit is closed; 4) the second multiport valve (2) is switched to position II; 5) the first multiport valve (1) is switched to position II; 6) the valve of the inert gas circuit is opened;7) the middle port of the third multiport valve (3) is switched to the port that leads to the residual outlet or - if present - to the fourth multiport valve (4), whereby if the middle port of the third multiport valve leads to the fourth multiport valve (4), a port of the multiport valve (4) is switched to the port that leads to the residual outlet; and 8) all valves (including multiport valves) return to their basic position. ;

[0040] It should be added that the solvent circuit pump begins pumping before step 4) is performed. Furthermore, if a gassed liquid is being withdrawn, the pressure regulator unit's brake capillary should be passed through. The corresponding multiport valve (22) should then also be switched to position II. This should preferably be done before step 6). The pump can be started simultaneously with one of steps 1) to 3) or even between. Furthermore, this pump is also shut off again in step 8).

[0041] If the device according to the invention is to be flushed or a blank sample is taken, step 5) is omitted, which means that only solvent is passed through the device's lines. If the sample is to be taken without solvent, step 4) is omitted. This means that the sample is forced out of the sample loop only by the inert gas.

[0042] The above sequence serves to illustrate the present method. It has already been mentioned that the multiport valves can also be linked together in a different way or a different sequence can be selected. For example, it would also be possible for the second multiport valve (2) to remain in the basic position, i.e. position I, and step 5) would therefore not be carried out. This would make it possible to provide an undiluted sample, which is useful for certain applications. The exemplary sequence also does not include the possibility of taking a blank sample. In such a case, the first multiport valve (1) would remain in the basic position, i.e. position I, and step 4) would not be carried out. This would only direct solvent to the sample vessel and be examined as a blank sample.

[0043] The valve position of the individual steps 1) to 8) or of all alternative process variants is usually held for a certain time to ensure that the liquids and gases are sufficiently conveyed through the lines. However, it is difficult to specify an exact minimum duration for the valve position because this depends on the exact design and the valves, lines, etc. used. In a preferred embodiment of the present invention, the valve positions of the individual steps 1) to 8) or of all alternative process variants are held for 1 to 120 seconds, preferably for 5 to 90 seconds.

[0044] The special feature of the present method is that it is possible to take an inert, non-backmixed sample in a short time. Starting from the basic position, the first sample can be taken within a few seconds after purging with inert gas in steps 1) to 3). Once the first sample has been taken, purging must first be carried out again before a further sample can be taken. This is the time-determining step of the method according to the invention. Nevertheless, the time intervals between two samples are comparatively short and amount to less than 150 seconds, preferably less than 135 seconds, preferably less than 120 seconds. The total duration of the method of steps 1) to 8) is therefore preferably a maximum of 480 seconds, further preferably a maximum of 300 seconds, particularly preferably a maximum of 200 seconds.

[0045] The device according to the invention is described in Fig. 1shown schematically. This is an exemplary embodiment and is not intended to limit the present invention.

[0046] Fig. 1shows an embodiment with 5 multiport valves (1, 2, 3, 4, 22). The sample circuit is defined by the first multiport valve (1), an inlet line (15) from the container (7), an outlet line (16) to the container (7), and the sample loop (14). The solvent circuit comprises a storage container (6) for the solvent, the second multiport valve (2), an inlet line (11) from the storage container (6), an outlet line (10) to the storage container (6), and a solvent loop (12). The pump, which transports the solvent from the storage container (6) via the inlet line (11) to the multiport valve (2), is not shown here. The sample vessel(s) (5) are filled via the sample distribution unit, which comprises a third multiport valve (3), at least one line (19) connected to the sample vessel (5), at least one line (20) leading away from the sample vessel (5) and connected to the fourth multiport valve, and the fourth multiport valve (4).It goes without saying that the fourth multiport valve can also be omitted here. The additional multiport valve (22) with brake capillary (24) represents the pressure regulation unit, which can be used to release pressure in a controlled manner and to allow the targeted and slow depressurization of the sample. All existing multiport valves (1, 2, 3, 4, 22) are connected via the inert gas circuit. The inert gas circuit comprises a valve (8) which controls the inflow of inert gas. The inert gas enters the device via the inlet line (9) and is initially fed to the second multiport valve (2). The outlet line (21) of the inert gas circuit then leads from the fourth multiport valve (4) to the residual outlet. All existing multiport valves (1, 2, 3, 4, 22) are connected via the inert gas circuit by means of lines (13, 17, 18, 23). To take a sample, first fill the sample loop (14) (position I as described above). Then, if necessary, the sample is purged with inert gas.with solvent from the solvent loop (12) from the sample loop (14) via line (17) to the multiport valve (22), from there via line 23 to the multiport valve (3) and from there via line (19) to the sample vessel (5). Examples

[0047] In a sampling system according to the invention, which is shown schematically in the Fig. 1 As shown, sampling was tested at high pressure. Example 1:

[0048] Toluene was placed in a reactor (Parr Instrument Company HD autoclave, 250 ml). The reactor was pressurized to 200 bar with nitrogen and heated to 145 °C. Once the required pressure and temperature were reached, diisobutene was added in a mass ratio of 80:20 toluene / diisobutene, and the resulting mixture was analyzed using the sampling system according to the invention by repeated sampling. Samples were taken after 3 minutes, 6 minutes, 10 minutes, 15 minutes, 30 minutes, 45 minutes, 60 minutes, 90 minutes, 1200 minutes, and 2400 minutes and analyzed for the mass ratio using gas chromatography (FID detector). A reproducible mass ratio of 80:20 toluene to diisobutene was found. Example 2:

[0049] In a reactor (Parr Instrument Company HD autoclave 250 ml), 135 g of toluene was placed with a catalyst system consisting of 12 mg Rh(acac)CO 2 and 0.15 g Alkanox P240. The mixture was heated to 140 °C, brought to 170 bar by pressurizing synthesis gas (CO : H 2 approximately 50:50), and thoroughly mixed.

[0050] After reaching the required pressure and temperature, 30g of 2-ethyl-1-hexene were added and the hydroformylation reaction was monitored using the sampling system according to the invention ( Fig. 1 ) by repeated sampling. Samples were taken after 15 minutes, 15 minutes, 30 minutes, 45 minutes, 75 minutes, 135 minutes, and 195 minutes and analyzed for the mass ratio of the reactants using gas chromatography (FID detector). Table 1: Gas chromatography results after automatic sampling Reaction time / min 0 15 30 45 75 135 195 Sampling system GC Alkene conversion / % 0 6,1 22,9 71,1 93,8 99,5 99,9

Claims

1. Apparatus for automated sampling of a liquid sample from a vessel in which there may be a pressure of at least 20 bar, preferably of at least 50 bar, further preferably of at least 100 bar, more preferably of at least 150 bar, wherein the apparatus comprises the following: • a sample circuit comprising a first multiport valve (1) having at least 6 ports, a feed conduit (15), a drain conduit (16) and a sample loop (14), wherein a liquid sample of the solution present in the vessel can be taken via the sample circuit; • a solvent circuit comprising a reservoir vessel (6) for the solvent, a second multiport valve (2) having at least 6 ports, a pump, a feed conduit (11), a drain conduit (10) and a solvent loop (12), wherein solvent for dilution of the sample can be added via the solvent circuit; • one or more sample vessels (5) into which the liquid sample, preferably diluted with the solvent, can be routed; • a sample distribution unit comprising a third multiport valve (3) having at least 3 ports and at least one conduit (19) connected to the one or more sample vessels (5), wherein the sample taken from the vessel can be routed via the conduit (19) into the at least one sample vessel (5); and • an inert gas circuit in which there is an inert gas, wherein the inert gas circuit comprises at least one valve (8), a feed conduit (9), a drain conduit (21), and conduits (13, 17, 18, 23) via which all the multiport valves present are connected to one another, characterized in that the apparatus for automated sampling comprises a pressure regulation unit with which the samples can be brought to ambient pressure, wherein the pressure regulation unit comprises a further multiport valve (22) having a restriction capillary (24) and wherein the further multiport valve (22) is disposed between the first multiport valve (1) and the third multiport valve (3).

2. Apparatus according to Claim 1, wherein the sample distribution unit has at least two multiport valves (3, 4).

3. Apparatus according to Claim 1 or 2, wherein the inert gas is nitrogen, argon or helium.

4. Apparatus according to any of the preceding claims, wherein the pressure in the vessel from which the sample is to be taken is not more than 500 bar, preferably not more than 490 bar, more preferably not more than 480 bar.

5. Apparatus according to any of the preceding claims, wherein two ports of the first multiport valve (1) are connected via two interfaces to the vessel, two ports to the sample loop (14), and two ports to the conduits of the inert gas circuit.

6. Apparatus according to any of the preceding claims, wherein two ports of the second multiport valve (2) are connected to the reservoir vessel (6) for the solvent, i.e. one inlet and one outlet, two ports to the solvent loop (12), and two ports to the conduits of the inert gas circuit.

7. Apparatus according to any of the preceding claims, wherein two ports of the third multiport valve (3) are connected to the conduits of the inert gas circuit, and the other port(s) to the at least one sample vessel (5).

8. Apparatus according to any of the preceding claims, wherein the first multiport valve (1) can be adjusted between at least two valve settings (I and II), wherein • in setting I the two ports that are connected via the interfaces to the vessel are each linked by a port connected to the sample loop, such that the liquid sample of the solution present in the vessel is routed via the inlet interface through the sample loop (14) and via the outlet interface back to the vessel, as a result of which the sample loop (14) is filled with sample; and • in setting II the two ports that are connected via the interfaces to the vessel are linked to one another, such that the solution is routed directly back to the vessel without passing through the sample loop (14), and the two ports that are connected to the sample loop (14) are each linked to a port connected to the conduits of the inert gas circuit, such that the sample present in the sample loop (14) can be routed via the inert gas circuit to the sample distribution unit and thence to at least one sample vessel (5).

9. Apparatus according to any of the preceding claims, wherein the second multiport valve (2) can be adjusted between at least two valve settings (I and II), wherein • in setting I the two ports that are connected to the reservoir vessel (6) are each linked to a port connected to the solvent loop (12), such that the solvent is routed with the aid of the pump from the reservoir vessel (6) via the solvent loop (12) back to the reservoir vessel (6), as a result of which the solvent loop (12) is filled with solvent; and • in setting II the two ports that are connected to the reservoir vessel (6) are linked to one another, such that the solvent is routed with the aid of the pump from the reservoir vessel (6) directly back to the reservoir vessel (6) without passing through the solvent loop (12), and the two ports connected to the solvent loop (12) are each linked to a port connected to the conduits of the inert gas circuit, such that the solvent present in the solvent loop (12) can be routed via the inert gas circuit to the first multiport valve (1).

10. Apparatus according to any of the preceding claims, wherein the inert gas circuit via which all the multiport valves present are connected to one another comprises the following conduits: • a conduit (9) that leads from an inert gas source to the second multiport valve (2) via a valve (8) that can be used to control the inert gas supply; • a conduit (13) that leads from the second multiport valve (2) to the first multiport valve (1); • a conduit (17) that leads from the first multiport valve (1) to the further multiport valve (22); • a conduit (23) that leads from the further multiport valve (22) to the third multiport valve (3), preferably to the middle port of the third multiport valve (3); • at least one conduit (19), preferably two or more conduits, that lead(s) from the third multiport valve (3) to the at least one or more than one sample vessel (5); • one conduit (20) each that leads from each sample vessel to the residue outlet, preferably one conduit (20) each that leads from each sample vessel to one of the ports of the fourth multiport valve (4), where these ports can each be switched to an additional port, and a conduit (21) that leads from the additional port of the fourth multiport valve (4) to the residue outlet.

11. Method of automated sampling of a liquid sample from a vessel in which there may be a pressure of at least 20 bar, preferably of at least 50 bar, further preferably of at least 100 bar, more preferably of at least 150 bar, using the apparatus according to any of Claims 1 to 10, wherein a) a liquid sample is taken from the vessel and stored intermediately in the sample loop (14) of the sample circuit; b) a solvent is taken from the reservoir vessel and stored intermediately in the solvent loop (12) of the solvent circuit; c) an inert gas is present in the conduits of the inert gas circuit; and d) the sample is taken by altering the position of the valve (8) present and of the multiport valves such that the solvent stored intermediately in the solvent loop (12) is routed by the inert gas to the sample stored intermediately in the sample loop (14), and the sample diluted with the solvent is transported thence via the sample distribution unit to one or more sample vessels (5).

12. Method according to Claim 11, wherein the default position of the valves and of the multiport valves of the apparatus according to any of Claims 1 to 10 has the following features: • the at least one valve (8) of the inert gas circuit is closed; • the first multiport valve (1) is set to setting I; • the second multiport valve (2) is set to setting I; • the further multiport valve (22) is set to setting I, wherein the conduits from the first multiport valve (1) and to the third multiport valve (3) via the further multiport valve (22) are connected to one another such that the restriction capillary (24) is bypassed; • the middle port of the third multiport valve (3) is switched to the port that leads to the residue outlet or, if present, to the fourth multiport valve (4); and • the port of the fourth multiport valve (4), if present, which is connected to the third multiport valve (3) is switched to the middle port of the fourth multiport valve (4), wherein the middle port leads to the residue outlet.

13. Method according to Claim 11 or 12, wherein the valve (8) of the inert gas circuit is opened first.

14. Method according to Claim 12 or 13, wherein the sample is taken by altering the above-described default position of the valves present, including multiport valves, according to the following sequence: 1) the at least one valve (8) of the inert gas circuit is opened, preferably for at least 5 seconds and up to 120 seconds, more preferably for up to 90 seconds; 2) the middle port of the third multiport valve (3) is switched to the port that leads to a sample vessel (5), in order to purge the sample vessel (5) with inert gas, and a port of the fourth multiport valve (4) that comes from the sample vessel (5) is optionally switched to the middle port of the fourth multiport valve (4) toward the residue outlet; 3) the at least one valve (8) of the inert gas circuit is closed; 4) the second multiport valve (2) is switched to setting II; 5) the first multiport valve (1) is switched to setting II; 6) the valve (8) of the inert gas circuit is opened; 7) the middle port of the third multiport valve (3) is switched to the port that leads to the residue outlet or - if present - to the fourth multiport valve (4), wherein, when the middle port of the third multiport valve (3) leads to the fourth multiport valve (4), a port of the multiport valve (4) is switched to the port that leads to the residue outlet; and 8) all valves, including multiport valves, go back to the default position.

15. Method according to any of Claims 11 to 14, wherein the total duration of the method steps 1) to 8) is not more than 480 seconds, preferably not more than 300 seconds, more preferably not more than 200 seconds.