Department of Chemistry, University of British Columbia, Vancouver, British Columbia, Canada.
Magn Reson Chem. 2020 Dec;58(12):1234-1248. doi: 10.1002/mrc.5094. Epub 2020 Sep 7.
This study focused on fundamental data acquisition parameter selection for a benchtop nuclear magnetic resonance (NMR) system with continuous flow, applicable for reaction monitoring. The effect of flow rate on the mixing behaviors within a flow cell was observed, along with an exponential decay relationship between flow rate and the apparent spin-lattice relaxation time (T1*) of benzaldehyde. We also monitored sensitivity (as determined by signal-to-noise ratios; SNRs) under various flow rates, analyte concentrations, and temperatures of the analyte flask. Results suggest that a maximum SNR can be achieved with low to medium flow rates and higher analyte concentrations. This was consistent with data collected with parameters that promote either slow or fast data acquisition. We further consider the effect of these conditions on the analyte's residence time, T1*, and magnetic field inhomogeneity that is a product of continuous flow. Altogether, our results demonstrate how fundamental acquisition parameters can be manipulated to achieve optimal data acquisition in continuous-flow NMR systems.
本研究专注于台式核磁共振（NMR）连续流系统基本数据采集参数的选择，适用于反应监测。观察了流速对流动池内混合行为的影响，以及流速与苯甲醛表观自旋-晶格弛豫时间（T1*）之间的指数衰减关系。我们还在各种流速、分析物浓度和分析物瓶温度下监测了灵敏度（由信噪比确定；SNR）。结果表明，在低至中等流速和较高分析物浓度下可以获得最大 SNR。这与以促进慢或快数据采集的参数收集的数据一致。我们进一步考虑了这些条件对分析物停留时间、T1*和连续流产物的磁场不均匀性的影响。总的来说，我们的结果表明如何操纵基本采集参数以在连续流 NMR 系统中实现最佳数据采集。
