Filtern
Erscheinungsjahr
Dokumenttyp
- Vortrag (142)
- Zeitschriftenartikel (77)
- Beitrag zu einem Tagungsband (35)
- Posterpräsentation (12)
- Buchkapitel (6)
- Forschungsbericht (4)
- Sonstiges (3)
- Beitrag zu einem Sammelband (2)
- Forschungsdatensatz (2)
- Monografie (1)
Sprache
- Deutsch (151)
- Englisch (133)
- Mehrsprachig (1)
Schlagworte
- Prozessanalytik (59)
- Online NMR Spectroscopy (36)
- Process Analytical Technology (36)
- Industrie 4.0 (34)
- Prozessindustrie (34)
- CONSENS (29)
- Process analytical technology (24)
- Online NMR spectroscopy (21)
- Reaction Monitoring (17)
- Digitalisierung (16)
Organisationseinheit der BAM
- 1 Analytische Chemie; Referenzmaterialien (118)
- 1.4 Prozessanalytik (117)
- 8 Zerstörungsfreie Prüfung (14)
- 8.6 Faseroptische Sensorik (10)
- 6 Materialchemie (5)
- 8.0 Abteilungsleitung und andere (5)
- 6.3 Strukturanalytik (4)
- 8.1 Sensorik, mess- und prüftechnische Verfahren (4)
- 3 Gefahrgutumschließungen; Energiespeicher (3)
- 1.3 Instrumentelle Analytik (2)
Paper des Monats
- ja (1)
Nur weit weniger als ein Prozent aller pharmazeutischen Wirkstoffe finden den Weg in die Anwendung. Grund dafür sind in fast allen Fällen die äußerst schlechten biopharmazeutischen Eigenschaften der Wirkstoffe, wie ihre Löslichkeit, Stabilität und – bei festen Darreichungsformen – ihre Kristalleigenschaften, auch wenn die Wirkstoffe eine gute Wirksamkeit oder gute toxikologische Eigenschaften aufweisen. Mit dem Trend zu höheren Molmassen bei chemischen Wirkstoffen nimmt ihre Löslichkeit in wässrigen Systemen rapide ab. Verbesserungen der Löslichkeit und des Auflösungsverhalten stellen heute die zentrale Herausforderung bei der Entwicklung neuer Arzneimittel dar und liegen im Fokus der aktuellen pharmazeutischen Forschung und Entwicklung.
Für eine Verbesserung der physikalisch chemischen Eigenschaften werden verschiedene Verfahren beforscht: Mikronisierung, gezielte Salzbildung bzw. Salzscreening, Solubilisierung mit Cosolventien oder die Nutzung von Polymeren als mögliche Transportwege.
Pharmazeutische Cokristalle bestehen aus einem Wirkstoff und einem sogenannten Cokri-stall-Bildner. Bei letzterem handelt es sich typischerweise um ein organisches Molekül, das ähnliche Struktureigenschaften wie der pharmazeutische Wirkstoff aufweist. Die Synthese und Charakterisierung von pharmazeutischen Cokristallen ist von patentrechtlicher Relevanz und Gegenstand aktueller Forschungen, da die Bildung solcher Cokristalle häufig mit einer Verbesserung der physikochemischen Eigenschaften der enthaltenen Wirkstoffe einhergeht. In den letzten Jahren ist es gelungen, insbesondere das Auflösungsverhalten der pharmazeutischen Wirkstoffe gezielt zu verbessern und dadurch eine optimierte Bioverfügbarkeit zu realisieren.
Um einige Einschränkungen der Methoden UV/VIS-Detektion und HPLC zu umgehen, verfolgen wir das Auflösungsverhalten der Cokristalle mittels Online-NMR-Spektroskopie als ein direktes Verfahren: Die Methode erlaubt zum einen die direkte Beobachtung und Quantifizierung individueller Species, die bei der Auflösung beteiligt sind, d. h. Wirkstoff(e), Cokristallbildner und Lösungsmittel lassen sich getrennt voneinander mit einer hohen zeitlichen Auflösung und spektraler Dispersion beobachten. Ferner kommt diese Me-thode ohne Kalibrierung aus, da die NMR-Spektroskopie eine "absolute Vergleichsmethode" ist. Darüber hinaus kann die absolute Konzentration gemessen werden, wenn gegen Standards gearbeitet wird. Der Einsatz dieses Verfahrens zum Studium des Auflösungsverhaltens ist völlig neu. Perspektivisch reizvoll ist die Weiterentwicklung zu einem mikroanalytischen Verfahren, das mit äußerst geringen Substanzmengen auskommt.
Berichtet wird über die automatisierte und spektral-modellgestützte Datenauswertung quantitativer Online-NMR-Spektren von technischen Systemen, die einen grundlegenden Beitrag zum Thematik Smart Sensors im Sinne kalibrierarmer bzw. kalibrierfreier Verfahren liefern.
Die quantitative Online-NMR-Spektroskopie ist besonders reizvoll für diese Thematik: Sie kommt durch den direkten Nachweis der Kernspins ohne Kalibrierung aus und arbeitet auch in Konzentrationsrandbereichen äußerst linear. Als „absolute Vergleichsmethode“ (direkte Proportionalität der Signale zu den Stoffmengen innerhalb eines Spektrums) ist die NMR-Spektroskopie für die durchgeführten Grundlagenuntersuchungen im Zusammenhang mit spektralen Modellen prädestiniert.
Within the Collaborative Research Center InPROMPT a novel process concept for the hydroformylation of long-chained olefins is studied in a mini-plant, using a rhodium complex as catalyst in the presence of syngas. Recently, the hydroformylation in micro¬emulsions, which allows for the efficient recycling of the expensive rhodium catalyst, was found to be feasible. However, the high sensitivity of this multi-phase system with regard to changes in temperature and composition demands a continuous observation of the reaction to achieve a reliable and economic plant operation. For that purpose, we tested the potential of both online NMR and Raman spectroscopy for process control. The lab-scale experiments were supported by off-line GC-analysis as a reference method.
A fiber optic coupled probe of a process Raman spectrometer was directly integrated into the reactor. 25 mixtures with varying concentrations of olefin (1-dodecene), product (n-tridecanal), water, n-dodecane, and technical surfactant (Marlipal 24/70) were prepared according to a D-optimal design. Online NMR spectroscopy was implemented by using a flow probe equipped with 1/16” PFA tubing serving as a flow cell. This was hyphenated to the reactor within a thermostated bypass to maintain process conditions in the transfer lines.
Partial least squares regression (PLSR) models were established based on the initial spectra after activation of the reaction with syngas for the prediction of unknown concentrations of 1-dodecene and n-tridecanal over the course of the reaction in the lab-scale system. The obtained Raman spectra do not only contain information on the chemical composition but are further affected by the emulsion properties of the mixtures, which depend on the phase state and the type of micelles. Based on the spectral signature of both Raman and NMR spectra, it could be deduced that especially in reaction mixtures with high 1-dodecene content the formation of isomers as a competitive reaction was dominating. Similar trends were also observed during some of the process runs in the mini-plant. The multivariate calibration allowed for the estimation of reactants and products of the hydroformylation reaction in both laboratory setup and mini-plant.
Monitoring chemical reactions is the key to chemical process control. Today, mainly
optical online methods are applied. NMR spectroscopy has a high potential for direct
loop process control. Compact NMR instruments based on permanent magnets
are robust and relatively inexpensive analysers, which feature advantages like low
cost, low maintenance, ease of use, and cryogen-free operation. Instruments for
online NMR measurements equipped with a flow-through cell, possessing a good
signal-to-noise-ratio, sufficient robustness, and meeting the requirements for
integration into industrial plants (i.e., explosion safety and fully automated data
analysis) are currently not available off the rack.
Intensified continuous processes are in focus of current research. Flexible (modular)
chemical plants can produce different products using the same equipment with short
down-times between campaigns and quick introduction of new products to the
market. In continuous flow processes online sensor data and tight closed-loop control
of the product quality are mandatory. If these are not available, there is a huge risk of
producing large amounts of out-of-spec (OOS) products. This is addressed in the
European Unionʼs Research Project CONSENS (Integrated Control and Sensing)
by development and integration of smart sensor modules for process monitoring and
control within such modular plant setups.
The presented NMR module is provided in an explosion proof housing of 57 x 57 x
85 cm module size and involves a compact 43.5 MHz NMR spectrometer together
with an acquisition unit and a programmable logic controller for automated data
preparation (phasing, baseline correction) and evaluation. Indirect Hard Modeling
(IHM) was selected for data analysis of the low-field NMR spectra. A set-up for
monitoring continuous reactions in a thermostated 1/8” tubular reactor using
automated syringe pumps was used to validate the IHM models by using high-field
NMR spectroscopy as analytical reference method.
Hydroformylation of short-chained olefins has been established as a standard industrial process for the production of C2 to C6 aldehydes. Using aqueous solutions of transition metal complexes these processes are carried out homogeneously catalyzed. A biphasic approach allows for highly efficient catalyst recovery. Regarding renewable feedstocks, the hydroformylation of long-chained alkenes (> C10) in a biphasic system, using highly selective rhodium catalysts has yet not been shown. Therefore, the Collaborative Research Center SFB/TR 63 InPROMPT develops new process concepts, involving innovative tuneable solvent systems to enable rather difficult or so far nonviable synthesis paths. One possible concept is the hydroformylation of long-chained alkenes in microemulsions. For this, a modular mixer-settler concept was proposed, combining high reaction rates and efficient catalyst recycling via the application of technical grade surfactants. The feasibility of such a concept is evaluated in a fully automated, modular mini-plant system within which the characteristics of such a multiphase system pose several obstacles for the operation. Maintaining a stable phase separation for efficient product separation and catalyst recycling is complicated by small and highly dynamic operation windows as well as poor measurability of component concentrations in the liquid phases. In this contribution, a model-based strategy is presented to enable concentration tracking and phase state control within dynamic mini-plant experiments. Raman spectroscopy is used as an advanced process analytical tool, which allows for online in-situ tracking of concentrations. Combined with optical and conductivity analysis optimal plant trajectories can be calculated via the solution of dynamic optimization problem under uncertainty. Applying these, a stable reaction yield of 40 % was achieved, combined with an oil phase purity of 99,8 % (total amount of oily components in the oil phase) and catalyst leaching below 0.1 ppm.
Process analytical techniques are extremely useful tools for chemical production and manufacture and are of particular interest to the pharmaceutical, food and (petro-) chemical industries.
Today, mainly optical online methods are applied. NMR spectroscopy has a high potential for direct loop process control. Compact NMR instruments based on permanent magnets are robust and relatively inexpensive analysers, which feature advantages like low cost, low maintenance, ease of use, and cryogen-free operation. Instruments for online NMR measurements equipped with a flow-through cell, possessing a good signal-to-noise-ratio, sufficient robustness, and meeting the requirements for integration into industrial plants (i.e., explosion safety and fully automated data analysis) are currently not available off the rack.
A major advantage of NMR spectroscopy is that the method features a high linearity between absolute signal area and sample concentration, which makes it an absolute analytical comparison method which is independent of the matrix. This is an important prerequisite for robust data evaluation strategies within a control concept and reduces the need for extensive maintenance of the evaluation model over the time of operation. Additionally, NMR spectroscopy provides orthogonal, but complimentary physical information to conventional, e.g., optical spectroscopy. It increases the accessible information for technical processes, where aromatic-toaliphatic conversions or isomerizations occur and conventional methods fail due to only minor changes in functional groups.
As a technically relevant example, the catalytic hydrogenation of 2-butyne-1,4-diol and further pharmaceutical reactions were studied using an online NMR sensor based on a commercially available low-field NMR spectrometer within the framework of the EU project CONSENS (Integrated Control and Sensing).
Currently research in chemical manufacturing moves towards flexible plug-and-play approaches focusing on modular plants, capable of producing small scales ondemand with short down-times between individual campaigns. This approach allows for efficient use of hardware, a faster optimization of the process conditions, and thus, an accelerated introduction of new products to the market. Driven mostly by the search for chemical syntheses under biocompatible conditions, so-called “click” chemistry rapidly became a growing field of research. The resulting simple one-pot reactions are so far only scarcely accompanied by an adequate optimization via comparably straightforward and robust analysis techniques. Here we report on a fast and reliable calibration-free online high field NMR monitoring approach for technical mixtures. It combines a versatile fluidic system, continuous-flow measurement with a time interval of 20 s per spectrum, and a robust, automated algorithm to interpret the obtained data. All spectra were acquired using a 500 MHz NMR spectrometer (Varian) with a dual band flow probe having a 1/16 inch polymer tubing working as a flow cell. Single scan 1H spectra were recorded with an acquisition time of 5 s, relaxation delay of 15 s. As a proof-of-concept, the thiol-ene coupling between N-boc cysteine methyl ester and allyl alcohol was conducted in non-deuterated solvents while its time-resolved behaviour was characterised with step tracer experiments Through the application of spectral modeling the signal area for each reactant can be deconvoluted in the online spectra and thus converted to the respective concentrations or molar ratios. The signals which were suitable for direct integration were used herein for comparison purposes of both methods.
The departure from the current automation landscape to next generation automation concepts for the process industry has already begun. Smart functions of sensors will simplify their use and enable plug-and-play integration, even though they may appear to be more complex at first sight. This is particularly important for concepts like self-diagnostics, self-calibration and self-configuration/parameterization. Intelligent field devices as parts of digital field networks, Inter-net Protocol (IP)-based connectivity and web interfaces, as well as advanced data analysis soft-ware will provide the basis for future projects like Industrie 4.0, Factory of the Future, or Industrial Internet of Things (IIoT). The talk summarizes the currently discussed general requirements for process sensors 4.0 and introduces an online NMR sensor as example. This sensor was developed to provide integrated control and sensing for sustainable operation of flexible intensified processes (CONSENS) funded by the European Union’s Horizon 2020 research and innovation programme.
Monitoring chemical reactions is the key to process control. Today, mainly optical online methods are applied, which are calibration intensive. NMR spectroscopy has a high potential for direct loop process control while cutting the calibration and validation needs to an minimum and thus exhibiting short set-up times. Compact NMR instruments make NMR spectroscopy accessible in industrial and harsh environments for advanced process monitoring and control.
Intensified continuous processes are in focus of current research. Flexible (modular) chemical plants can produce different products using the same equipment with short down-times between campaigns and quick introduction of new products to the market. In continuous flow processes online sensor data and tight closed-loop control of the product quality are mandatory. Data analysis techniques are available but currently mostly used for off-line data analysis to detect the causes of variations in the product quality.
This is addressed within the EU’s Research Project CONSENS by the development and integration of a smart NMR module for process monitoring. The presented NMR module is provided in a mobile explosion proof housing and involves a compact spectrometer together with an acquisition unit and a programmable logic controller for automated data preparation (phasing, baseline correction), and evaluation. Such “smart sensors” provide the basis for the future project “Industrie 4.0”, and Industrial Internet of Things (IIoT), along with current requirements to process control, model based control, or soft sensing. The module transforms the acquired online spectra of various technically relevant reactions to either conventional 4‒20 mA signals as well as WiFi based OPC-UA communication protocols, which enables NMR-based advanced process control and funny discussions with plant managers along with automation and safety engineers.
Quantitative NMR Spectroscopy (qNMR) provides the most universally applicable form of direct purity determination without need for reference materials of impurities or the calculation of response factors but only exhibiting suitable NMR properties. Broadly accepted validation methods of qNMR spectroscopy will give users the tools to exploit qNMR more easily and enable them to speed up analytical method development and reduce the time and financial burden.
The first initiative towards a worldwide agreement goes back to a panel discussion at PANIC 2014 (Practical Applications of NMR in Industry Conference) in Chicago. Since that, the Validation Workshop takes place following the PANIC Conference each year, last in 2017 with a turnout of over 50 people. The group aims at identifying a network of NMR people concerned with validation that can ultimately assist each other through the validation process, harmonize the terminology and a standard approach for NMR validations and position the guidelines produced by consensus of the NMR community so that accreditation agencies can use this process.