Till sidans topp

Sidansvarig: Webbredaktion
Sidan uppdaterades: 2012-09-11 15:12

Tipsa en vän

Monitoring polydispersity… - Göteborgs universitet Till startsida
Till innehåll Läs mer om hur kakor används på gu.se

Monitoring polydispersity by NMR diffusometry with tailored norm regularisation and moving-frame processing

Artikel i vetenskaplig tidskrift
Författare M. Urbanczyk
Diana Bernin
A. Czuron
Krzysztof Kazimierczuk
Publicerad i Analyst
Volym 141
Nummer/häfte 5
Sidor 1745-1752
ISSN 0003-2654
Publiceringsår 2016
Publicerad vid Svenskt NMR-centrum vid Göteborgs universitet
Sidor 1745-1752
Språk en
Länkar dx.doi.org/10.1039/c5an02304a
Ämnesord nuclear-magnetic-resonance, field gradient nmr, diffusion measurements, curve resolution, spectroscopy, algorithm, dosy, inversion, mixtures, polymers, Chemistry
Ämneskategorier Kemi


Nuclear magnetic resonance (NMR) is currently one of the main analytical techniques applied in numerous branches of chemistry. Furthermore, NMR has been proven to be useful to follow in situ reactions occurring on a time scale of hours and days. For complicated mixtures, NMR experiments providing diffusion coefficients are particularly advantageous. However, the inverse Laplace transform (ILT) that is used to extract the distribution of diffusion coefficients from an NMR signal is known to be unstable and vulnerable to noise. Numerous regularisation techniques to circumvent this problem have been proposed. In our recent study, we proposed a method based on sparsity-enforcing l(1)-norm minimisation. This approach, which is referred to as ITAMeD, has been successful but limited to samples with a 'discrete' distribution of diffusion coefficients. In this paper, we propose a generalisation of ITAMeD using a tailored l(p)-norm (1 <= p <= 2) to process, in particular, signals arising from 'polydisperse' samples. The performance of our method was tested on simulations and experimental datasets of polyethylene oxides with varying polydispersity indices. Finally, we applied our new method to monitor diffusion coefficient and polydispersity changes of heparin undergoing enzymatic degradation in real time.

Sidansvarig: Webbredaktion|Sidan uppdaterades: 2012-09-11

På Göteborgs universitet använder vi kakor (cookies) för att webbplatsen ska fungera på ett bra sätt för dig. Genom att surfa vidare godkänner du att vi använder kakor.  Vad är kakor?