Study of the nettle (Urtica diоica) lignin by orbitrap mass spectrometry with atmospheric pressure photoionization

T16N1

I.I. Pikovskoi, D.S. Kosyakov, I.S.  Shavrina, N.V. Ul’yanovskii

The orbital ion trap high-resolution mass spectrometry method with atmospheric pressure acetone-doped photoionization was first used to characterize the structure of lignins of herbaceous plants using the example of nettle (Urtíca dióica) dioxane lignin. The obtained mass spectrum contains about 3,000 peaks of deprotonated molecules of lignin oligomers in the molecular mass range up to 1.6 kDa. The study of tandem mass spectra and the composition of monomers formed during the collision-induced dissociation of lignin macromolecules showed the special role of p-hydroxycinnamic acids in the formation of nettle lignin. Based on the results of tandem mass spectrometry, possible structures of nettle lignin oligomers, which are formed by the addition of guaiacyl- and syringylpropane units with their subsequent etherification with p-coumaric, ferulic and dihydroferulic acids, are proposed.

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Study of the products of alkaline decomposition of hydrolysis lignin by high resolution mass spectrometry with atmospheric pressure photoionization

T14N1

D.S. Kosyakov, E.V. Ipatova, S.M. Krutov, N.V. Ul’yanovskii, I.I. Pikovskoi

A method of high resolution mass spectrometry with acetone doped atmospheric pressure photoionization was used to study the products of alkaline solvolysis of hydrolysis lignin. It was found that the mass spectrum of hydrolysis lignin depolymerization products comprises about seven thousand peaks of oligomers containing up to 10 aromatic units with an average molecular weight of 150 Da. The calculation of the elemental compositions of all detectable oligomers and their visualization in van Krevelen coordinates allowed us to show that the studied sample is different from the native (virgin released) lignin due to the presence of fractions with a high oxygen content and highly unsaturated condensed structures, including polyaromatic hydrocarbons. To characterize the structural units of lignin oligomers an approach based on the collision induced dissociation of precursor ions in a broad m/z range was used.

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Хроматомасс-спектрометрический анализ эфиров фосфорной и фосфоновой кислот

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