Development of ultrahigh-throughput NMR spectroscopic analysis utilizing capillary flow NMR technology

An ultrahigh-throughput method for acquiring H-1 NMR spectra is described. By constructing a continuous flow system utilizing an HPLC pump, autosampler, and a capillary flow NMR probe, it was possible to inject samples into the NMR spectrometer every 30 s using a continuous flow rate of 30 mu L/min. H-1 NMR spectroscopic data were acquired continuously into a pseudo-2D data file, with a 96-well-plate completed in < 50 min. Spectra in continuous flow mode were readily obtained from similar to 3.4 mu g (500 MHz), while the LOD was < 850 ng. There was found to be little variation in either sample broadening within the flow system or signal intensities between multiple injections. Ibis system offers several advantages over more conventional NMR spectroscopic analyses, notably the limited solvent required, high sensitivity, high speed, and improved spectral quality as a result of reduced spectral "dead" regions resulting from residual solvent levels.