The Mathias Nilsson Research Group




The focus of our research is the development and application of novel methods in liquids NMR spectroscopy.

NMR is most commonly applied to relatively pure substances in solution, where it is unparalleled as a technique for extracting structural, chemical and physical information.
Pureshift DOSY: proton homodecoupling reduces the overlap


The analysis of mixtures, a large part of our work, is a particularly challenging area because it is often difficult

to tell which NMR signals come from which molecular species.


The most important current method for analysis of intact mixtures by NMR is diffusion-ordered spectroscopy (DOSY), where signals from different molecular species

are differentiated by their diffusion behaviour (i.e. molecular size).


When NMR signals are well separated, analysis of DOSY data is relatively straightforward, but when signals overlap

(as is common) analysis is much more difficult.


500 MHz proton spectrum of Port Wine



 We are developing methods to deal with such overlapping  data.


 The effects of overlap can be attacked both from the  signal processing  end and from the spectroscopy end of  the problem; both these approaches form part of our  current  research.





From the spectroscopy end, a reduction in overlap can be  achieved either by reducing spectral  complexity, as in  pure shift DOSY, or by increasing the number of spectroscopic dimensions, as in  the variety of

3D DOSY methods we have developed.


From the signal processing end, covariance of the experimental data (e.g. the fact that all the  signals from a particular species should show the same diffusion properties) can be taken  advantage of by using multivariate methods for analysis.


We are also looking at combining DOSY with other types of experiment to increase the resolving  power in the diffusion dimension, as well as properties other than diffusion that

may allow the  signals from different chemical species to be separated.