Direct quantification of M/G ratio from (13)C CP-MAS NMR spectra of alginate powders by multivariate curve resolution
| Autor: | Stefan Steuernagel, Søren Balling Engelsen, Tina Salomonsen, Flemming H. Larsen, Henrik Max Jensen |
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| Rok vydání: | 2009 |
| Předmět: |
Multivariate curve resolution
Magnetic Resonance Spectroscopy Correlation coefficient Molecular Structure Solution state Chemistry Alginates Hexuronic Acids Organic Chemistry Analytical chemistry General Medicine Biochemistry Spectral line Analytical Chemistry Glucuronic Acid Magic angle spinning Mannuronic acid Molecule Sample preparation |
| Zdroj: | Carbohydrate research. 344(15) |
| ISSN: | 1873-426X |
| Popis: | Multivariate curve resolution (MCR) was applied to (13)C cross-polarisation (CP) magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectra of non-depolymerised alginate powders obtained from brown seaweed plus a pure mannuronate sample isolated from Pseudomonas fluorescens for estimation of the mannuronic acid/guluronic acid ratio (M/G ratio). An excellent MCR model with a correlation coefficient of r(2)=0.99 was established between the estimated M/G ratios and the M/G ratios obtained from the traditional (1)H solution state NMR method. The new method allows for successful determination of the M/G ratio independent of the calcium content (at least up to 2.4%, which was the upper limit in this study) with a root mean square error of prediction of 0.05. It is thus concluded that (13)C CP-MAS NMR in combination with multivariate curve resolution is a reliable, convenient (no sample preparation is required) and relatively rapid method for M/G ratio determinations of alginates and it may serve as a good alternative to the chemical techniques traditionally used. |
| Databáze: | OpenAIRE |
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