Application of a new micro-reactor  1 H NMR probe head for quantitative analysis of fast esterification reactions

Brächer, Alexander; Behrens, Richard; Harbou, Erik von; Hasse, Hans

doi:10.1016/j.cej.2016.07.045

Cited by 23 publications

(41 citation statements)

References 44 publications

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“…The experimental setup used for the kinetic study of the formation of methyl acetate is described in detail by Brächer et al The measurements were carried out using a microreactor NMR probe, which is well suited for the monitoring of fast reactions (for details, see previous studies). Thus, the time between mixing of the reactants (i.e., the start of the reaction) and analysis in the NMR flow cell is very short (less than 2 s), which allows monitoring of fast reactions .…”

Section: Methodsmentioning

confidence: 99%

“…Nuclear magnetic resonance (NMR) spectroscopy is an important technique for qualitative and quantitative analysis of complex multicomponent mixtures. As it features noninvasive measurements and enables quantitative evaluation of the measurements without prior calibration, it is especially suited for online monitoring of reactions and processes . In the frame of reaction and process monitoring, typically a large set of NMR spectra is acquired.…”

Section: Introductionmentioning

confidence: 99%

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Application of a new method for simultaneous phase and baseline correction of NMR signals (SINC)

Steimers

Sawall

Behrens

et al. 2019

Magnetic Reson in Chemistry

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Recently, we presented a new approach for simultaneous phase and baseline correction of nuclear magnetic resonance (NMR) signals (SINC) that is based on multiobjective optimization. The algorithm can automatically correct large sets of NMR spectra, which are commonly acquired when reactions and processes are monitored with NMR spectroscopy. The aim of the algorithm is to provide spectra that can be evaluated quantitatively, for example, to calculate the composition of a mixture or the extent of reaction. In this work, the SINC algorithm is tested in three different studies. In an in-house comparison study, spectra of different mixtures were corrected both with the SINC method and manually by different experienced users. The study shows that the results of the different users vary significantly and that their average uncertainty of the composition measurement is larger than the uncertainty obtained when the spectra are corrected with the SINC method. By means of a dilution study, we demonstrate that the SINC method is also applicable for the correction of spectra with low signal-to-noise ratio. Furthermore, a large set of NMR spectra that was acquired to follow a reaction was corrected with the SINC method. Even in this system, where the areas of the peaks and their chemical shifts changed during the course of reaction, the SINC method corrected the spectra robustly. The results show that this method is especially suited to correct large sets of NMR spectra and it is thus an important contribution for the automation of the evaluation of NMR spectra.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Application of a new method for simultaneous phase and baseline correction of NMR signals (SINC)

Steimers

Sawall

Behrens

et al. 2019

Magnetic Reson in Chemistry

Self Cite

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“…. More details on the microreactor NMR probe head as well as on the whole experimental setup are given in , .…”

Section: Micromixer Nmr Probe Headmentioning

confidence: 99%

“…together with the prediction using a kinetic model that was parameterized based on this experimental data. The kinetic model is a simple second‐order approach based on activities with the kinetic constant of the forward and the backward reaction as the two model parameters (for details see ). The results show that the microreactor NMR probe head is well‐suited for studying the kinetics of reactions under conditions relevant for industrial applications that reaches chemical equilibrium within about 20 s.…”

Section: Kinetic Measurementsmentioning

confidence: 99%

Studying Fast Reaction Kinetics with Online NMR Spectroscopy

Harbou

Behrens

Berje

et al. 2016

Chemie Ingenieur Technik

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A liquid thermostated microreactor Nuclear Magnetic Resonance (NMR) probe head is presented that facilitates the investigation of kinetics of fast reactions. With this setup, reaction kinetics can be studied in a broad temperature (–20 – 100 °C) and pressure range (0 – 60 bar). The setup and NMR probe head are discussed from a reaction engineering standpoint based on experiments and simulations. The microreactor probe head widens significantly the range of applications of online NMR spectroscopy for reaction and process monitoring.

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“…Therefore, high-resolution spectra are achievable of molecules being consumed by, and excreted from, the biological sample in the bioreactor. This approach has been successfully implemented to monitor chemical reactions [ 24 , 25 , 26 , 27 , 28 , 29 , 30 ], including the use of low-field benchtop NMR spectrometers for both chemical [ 31 , 32 ] and biological applications [ 33 , 34 ]. Importantly, the interface to the NMR spectrometer is simplified in comparison with the in situ operation mode: only tubing and pumps are required for sample shuttling from a suitable external bioreactor station; in effect, the biological culturing becomes a module to be coupled to the NMR measurement system.…”

Section: Introductionmentioning

confidence: 99%

A Nuclear Magnetic Resonance (NMR) Platform for Real-Time Metabolic Monitoring of Bioprocesses

et al. 2020

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We present a Nuclear Magnetic Resonance (NMR) compatible platform for the automated real-time monitoring of biochemical reactions using a flow shuttling configuration. This platform requires a working sample volume of ∼11 mL and it can circulate samples with a flow rate of 28 mL/min., which makes it suitable to be used for real-time monitoring of biochemical reactions. Another advantage of the proposed low-cost platform is the high spectral resolution. As a proof of concept, we acquire 1H NMR spectra of waste orange peel, bioprocessed using Trichoderma reesei fungus, and demonstrate the real-time measurement capability of the platform. The measurement is performed over more than 60 h, with a spectrum acquired every 7 min, such that over 510 data points are collected without user intervention. The designed system offers high resolution, automation, low user intervention, and, therefore, time-efficient measurement per sample.

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Application of a new micro-reactor 1 H NMR probe head for quantitative analysis of fast esterification reactions

Cited by 23 publications

References 44 publications

Application of a new method for simultaneous phase and baseline correction of NMR signals (SINC)

Application of a new method for simultaneous phase and baseline correction of NMR signals (SINC)

Studying Fast Reaction Kinetics with Online NMR Spectroscopy

A Nuclear Magnetic Resonance (NMR) Platform for Real-Time Metabolic Monitoring of Bioprocesses

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