Question

Deconvolution of the measured spectra

I have no experience with the process of deconvolution, can anyone help me to do deconvolution of individual measured data (11 individual samples).

For each type of lignins, a stock solution was prepared by dissolving lignin powder in NaOH (0.1 M). UV-VIS absorption spectra were registered using solution of lignin on a CECIL spectrophotometer, absorption region 200 -450 nm, scan speed 5 nm/s and resolution 1 nm. Measured values of absorbance were normalized by absorption maxima for even samples, respective.

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  • Gyorgy Banhegyi · Bay Zoltán Nonprofit Ltd. for Applied Research
    It has been a ling time ago that I was involved in such a task (fitting UV and CD spectra simultaneously). Sorry, I could not open your opj file (what program can be used?). The easiest fitting procedure if you have component spectra and you assume that only their linear combination can appear in the mixture. Than it is a simple linear fit using leas squares. If you have the component spectra and you can deconvolute them into regular (Gaussian, Lorentzian or mixture) bands, you can use these components in fitting the mixture spectra. If you use Newton Raphson or other stepwise porcedure, you will get an optimized spectral decomposition. In the stricter sense deconvolution means using an instrument function (which conbóvolutes the measured spectra) and you deconvolution. This involves Fourier tansformation. The peaks become sharper but you get "ghost" bands as well. I am sure there are several commercially available sftwares for that. In the earliy times we had to write them ourselves.
  • Michal Jablonsky · Slovak University of Technology in Bratislava
    Data format in xls
  • Gyorgy Banhegyi · Bay Zoltán Nonprofit Ltd. for Applied Research
    Thank you for sending the data in xls format. Apparently most change is present in the 230-330 nm range. It seems that there is a shifrt from 243 to aBOUT 253 (I don't know what parameter is changed in your system) and intensity of the 285 nm component also changes considerably.
  • Michal Jablonsky · Slovak University of Technology in Bratislava
    Thank for yor answer. These spectra represent measurements of individual commercial lignin and precipitated lignin isolated from black liquor kraft and modified alkaline anthraquinone cooking.
  • Gyorgy Banhegyi · Bay Zoltán Nonprofit Ltd. for Applied Research
    Please find below some papers on ligiUV/Vis - probably you know most of them:
    http://www.ipst.gatech.edu/faculty/ragauskas_art/technical_reviews/UV%20analysis%20of%20Lignin.pdf
    ISOLATION OF LIGNIN FROM WOOD - Theseus
    publications.theseus.fi/.../Li_Jingjing.pdf... - Oldal lefordítása
    Fájlformátum: PDF/Adobe Acrobat - Gyorsnézet
    with reflux condenser, it was called Klason lignin. These lignins were characterized by UV and FTIR spectroscopy. According to the results, the lignin content ...
    http://www.tandfonline.com/doi/abs/10.1081/WCT-100104222 - important, model compounds
    http://www.ncsu.edu/bioresources/BioRes_02/BioRes_02_3_459_471_Parasuraman_SBOF_HW_Lignin_Est_UV_Demethyl.pdf - alos contains information on model compounds
    http://www.cellulosechemtechnol.ro/pdf/CCT9-10-2009/399-408.pdf
    http://link.springer.com/article/10.1007/BF00614842#page-1 - model compounds
    I hope this helps somewhat - unfortunately I have no time to read them critically myself
  • Michal Jablonsky · Slovak University of Technology in Bratislava
    Thanks

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