The acquired spectrum is shown as a black line, the GSD peaks are blue, the sum of these peaks is red, and the residual is green. GSD peak picking was applied using the default settings: average peaks, 2 fitting cycles. We show, below, the 1H NMR spectrum of estradiol dissolved in DMSO-d6. The sum integral for a region should be very close to the summed areas of all peaks in that region, regardless of their classification. Small peaks from 13C satellites, and artifacts.Solvent peaks – residual solvent, contaminating water.

Mnova attempts to categorise peaks (approximately) and specify that they are related to: Peak type classification is an automatic procedure with GSD.

GSD peak area determination performance is constant even down to a SNR of 20.

This, especially when very precise phase adjustment is a crucial requirement for sum integration.

Although GSD is not insensitive to phase mis-set, there is sufficient tolerance for minor error.

A resolution enhancement is achieved with GSD.

GSD is insensitive to imperfect baseline and whether a peak overlaps with others.

GSD will provide peak lists along with the calculated area.

In the context of qNMR and this discussion we need to remember: Global Spectrum Deconvolution (GSD) and peak type classification I will show two examples where it might be applied, and how to actually do this in Mnova. I wish to introduce you here to this novel solution to a common, practical problem in qNMR analysis.

We worked with Torsten Schönberger of the German Bundeskriminalamt (BKA) on this problem, and came up with a new integration mode that we call “edited sum” (ES). There are occasions where a conventional “sum” integration is spoiled by the unfortunately placed impurity peaks in the region that we would like to accurately integrate. For conventional spectral analysis GSD peak picking and integration has a lot to offer, but for the very best results that qNMR usually demands “sum” integration is king. Dr John Gauvin (DSM, Holland) recently gave an excellent webinar presentation where he compared the errors and accuracy that can be expected when either “sum” or “peaks” (GSD) integration is used.

QNMR is a common theme in my blogs, and it is always interesting and fun to speak with the growing number of like-minded colleagues.

Mestrenova integral text values