hide
Free keywords:
-
Abstract:
Flow NMR spectroscopy finds more and more interest in the field of natural science, pharmaceutical industry and engineering science. Due to its broad application, flow NMR spectroscopy can give information from gaseous, supercritical and liquid substances. Besides the well-known information of NMR spectra, it is possible to observe reactions and also to investigate reaction kinetics.
Hereby, acquisition of quantitative NMR spectra is still challenging. By inserting immobilized paramagnetic substances in the flow path it is possible to decrease long spin-lattice relaxation times of nuclei like 13C and protons in supercritical fluids. This will increase the signal intensity of NMR spectra in flow mode. Compared with the static experiment, the use of immobilized paramagnetic substances in the flow path and an applied flow rate of 20 ml/min leads to an increase in the signal-to-noise ratio by 75.
Besides the observation of reactions themselves (e.g. amines in supercritical carbon dioxyd), flow NMR spectroscopy is useful to investigate reaction kinetics. Therefore, thermodynamic data can be obtained by quantitative analysis of NMR spectra.
