Solvent suppression techniques for coupling of size exclusion chromatography and H NMR using benchtop spectrometers at 43 and 62 MHz.

The characterisation of polymeric materials in their full complexity of chain length, monomeric composition, branching and functionalization is a tremendous challenge and is best tackled by tailored multi-dimensional coupled analytical and detection techniques. Herein, we focus on the improvement of an affordable but information rich 2D-method for polymer analysis: the online hyphenation of benchtop H NMR spectroscopy with size exclusion chromatography (SEC). The main benefit of this approach is correlated information of chain length (SEC) to chemical composition (H NMR).

Highly Resolved Pure-Shift Spectra on a Compact NMR Spectrometer.

Benchtop NMR spectrometers experience a great success for a wide range of applications. However, their performance is highly limited by peak overlaps. Emerging "pure-shift NMR" (PS NMR) methods have been intensively used at high field to enhance the resolution by homodecoupling strategies.

Benchtop NMR for the monitoring of bioprocesses.

This mini-review highlights the potential of benchtop nuclear magnetic resonance (NMR) for the monitoring of bioprocesses. It describes recent perspectives opened by the reduced size of devices in relaxometry, magnetic resonance imaging and NMR spectroscopy. In particular, the recent emergence of the benchtop NMR spectroscopy gives access to many applications thanks to the implementation of advanced experiments.

Diffusion-ordered spectroscopy on a benchtop spectrometer for drug analysis.

The first reported two-dimensional diffusion-ordered spectroscopy (DOSY) experiments were recorded at low field (LF) on a benchtop NMR spectrometer using the BPP-STE-LED (bipolar pulse pair-stimulated echo sequence with a longitudinal eddy current delay) pulse sequence which limits phase anomalies and baseline discrepancies. A LF DOSY map was first obtained from a solution of a model pharmaceutical formulation containing a macromolecule and an active pharmaceutical ingredient. It revealed a clear separation between the components of the mixture and gave apparent diffusion coefficients (ADC) values consistent with those measured from the reference high field experiment.