NMRDG and MSG Spring Meeting Report 2017

NMR Discussion Group and Molecular Spectroscopy Group

2017 Spring Meeting

Low Level Detection and Quantification by NMR Spectroscopy

Wednesday 29th March 2017

The Royal Society of Chemistry Molecular Spectroscopy and Nuclear Magnetic Resonance Discussion Groups brought together an excellent line up of speakers for the Spring meeting. The theme for the meeting “Low level detection and quantification by NMR” included talks exploring what this means for different NMR technologies, covering solution state NMR, solid state NMR and benchtop/low field NMR. The speakers discussed approaches to overcome the sensitivity limitations of conventional low level detection and quantification by NMR. These including ppm level quantification using cryoprobes, quantification of polymorphism using ssNMR,NMR methods for simplifying spectra and expanding the range of 19F NMR for quantitative analysis. Also discussed were the different methods of hyperpolarisation that are becoming more prevalent within NMR, both for solution state and solid state NMR, and the effect these sensitivity enhancements make to limits of detection and the implications for quantification.

The meeting was opened by Dr Michael Maiwald from the BAM Federal Institute for Materials Research and Testing in Berlin. In his talk “How far does the light shine? A check-up of quantitative high and low field NMR spectroscopy”, Michael explained that instrument stability and temperature control are equally, if not more important than field strength when it comes to having robust and repeatable methods. This was followed by Dr Ian Jones from AstraZeneca, Macclesfield, delivering a talk on “Development and Validation of a Selective NMR Method for Cleaning Validation in a GMP Pharmaceutical Production Plant” and exemplifying the ways in which selective excitation experiments with cryoprobes can achieve single figure ppm level detection in a matter of minutes, given the right sample. The morning session concluded with a lecture from Dr Marco Tessari, of the Radboud University, Netherlands, “Quantitative trace analysis of complex mixtures using SABRE Hyperpolarization“, in which he described the successful use of standard addition experiments to enable quantification despite the limitations of non-uniform enhancement.

Following an enjoyable lunch with time to catch up with old colleagues, collaborators and new contacts, Prof. Gareth Morris (University of Manchester) delivered an excellent lecture “New NMR techniques for high dynamic range samples” outlining some of his group’s recent work developing new broadband 19F NMR, 13C satellite suppression, pure shift and selective TOCSY experiments. Next to present was Prof. Ulrich Günther from the University of Birmingham, “NMR based metabolic flux analyses in cancer cells” giving a detailed lecture concerning the use of NMR to follow metabolic pathways and help us to better understand their role in oncology. Ulrich clearly demonstrated the requirements for achieving low limits of detection in this discipline, for obtaining optimal information with respect to a metabolic profile and subsequently relating to cellular activity.

For the final session of the day we switched our attention to solid-state NMR, with one of our hosts, Dr Tran Pham, from GlaxoSmithKline, talking about the “Use of ssNMR for quantitative analysis of polymorphism in API and drug product”. Tran outlined an elegant approach for quantifying the amount of amorphous and crystalline material within pharmaceutical drug substances and products to help understand the effect on the dissolution profile of the latter. The meeting was concluded with a talk from Dr Jeremy Titman, University of Nottingham, “Dynamic Nuclear Polarisation Enhanced Solid-state NMR Studies of Surfaces of Materials”. Jeremy highlighted the strengths and potential weaknesses faced with utilising this complex, surface selective technology and described efforts to routinely achieve a 70 fold increase in sensitivity.

Many thanks to my organising committee colleagues Stephen Byard (NMRDG), John Parkinson (NMRDG) and Ben Bardsley (MSG) for all their efforts in making the meeting a success, to GSK for hosting the event and the RSC and AstraZeneca for their financial support.

Steve Coombes (MSG chairman).