Sensitivity Optimization in Continuous-Flow FTNMR

Practical aspects of real-time reaction monitoring using multi-nuclear high resolution FlowNMR spectroscopy

“…50 WET pulse sequences are much more effective in suppressing solvent signals in flow than presaturation due to the significantly shorter pulse sequences employed in WET which are less affected by sample motion. 51,52 With advanced WET techniques it is also possible to simultaneously suppress multiple resonances (Fig. S8 †) including their carbon satellites very effectively ( Fig.…”

Quantitative high-resolution on-line NMR spectroscopy in reaction and process monitoring

“…The theory of flow NMR is well documented in reviews [36][37][38] and papers on special topics like signal enhancement in flowing liquids [39][40][41]. In order to achieve full Boltzmann distribution, a prerequisite for quantitative measurements, the sample must reside longer than 5 times the spin lattice relaxation time of the slowest relaxing nucleus T 1;max inside the pre-magnetization volume of the magnetic field prior to detection.…”

Continuous Flow 1H and 13C NMR Spectroscopy in Microfluidic Stripline NMR Chips

“…The apparent relaxation delays of the experiment are affected, as both the observed spin–lattice relaxation time ( T 1 obs ) and the observed spin–spin relaxation time ( T 2 obs ) decrease. 35,41,42 The stationary value of T 1 reflects the time constant for the spins to return to thermal equilibrium after receiving an rf pulse, which poses limitations on the repetition rate. However, when the analyte flows through the detection area during acquisition, the spins can be refreshed faster than the stationary value of T 1 , the acquisition delay between scans can be shortened.…”