4DOSY - Simple and efficient DOSY experiments analysis
CASC4DE offers 4DOSY, an efficient method, based on the PALMA algorithm and a maximum entropy (MaxEnt) / l1 hybrid regularization, for the analysis of DOSY experiments.
The service proposed by CASC4DE is associated to the following work:
PALMA, an improved algorithm for DOSY signal processing
A. Cherni, E. Chouzenoux and M.-A. Delsuc 2017
Analyst, 2017, 142, 772-779
NMR is a preferred method for determining the diffusion coefficients of species in solution. The 2D DOSY NMR experiment is particularly effective for studying complex mixtures, molecular interactions, polymers, and other such systems.
Analyzing DOSY data requires using the inverse Laplace transform (iLT), especially when dealing with polydisperse samples. From the work cited above, we implement a solution that involves a splitting scheme and proximity operators. By using a Maximum Entropy and l1 hybrid regularization, the algorithm quickly converges and yields results that are robust to experimental noise. The technique is capable of accurately reproducing both monodisperse and polydisperse systems.
- The program actually supports experiments acquired on Bruker instruments. The support of Jeol data format will soon be available.
- The program only handles 1H data-set for the moment.
- The majority of algorithm parameters are adjustable for tuning.
↪ Do not hesitate to contact us if interested, we can provide you with an access to our demo server for the solution.
Figure extracted from the paper cited above, representative of the results that can be obtained using 4DOSY:
Comparison of two DOSY experiments on a brown algae extracts. a) the aromatic (empty) and aliphatic regions; b) the same brown algae extract with 0.16 mg.mL-1 of chloroquine added, showing the aromatic signals and the methyl signal outlined with an arrow in the spectrum, the dashed horizontal label is at 285 µm2s-1; c) the 1D spectrum of the brown algae extract with added chloroquine. In all three spectra, the aromatic panel is plotted four times lower than the aliphatic panel.