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Dosage du polyisoprène et des résines de la biomasse de guayule (Parthenium argentatum) par spectroscopie proche infrarouge (SPIR) : méthodes d'extraction par solvant de référence
| Content Provider | Semantic Scholar |
|---|---|
| Author | Suchat, Sunisa |
| Copyright Year | 2012 |
| Abstract | Measurement of resin and polyisoprene in Parthenium argentatum (guayule) biomass using near infrared spectroscopy (NIRS) -Associated solvent-based reference methods .A protocol based on sequential extraction with acetone (resin) and hexane (polyisoprene, PI) with accelerated solvent extraction (ASE) was optimized and selected (maximized yield; adapted to large series) instead of Soxhlet and homogenizer. Quantification was first based on extract weight (gravimetry). Hexane extract was maximized at 120°C, after acetone steps at 40°C, through an experimental design. Cross contamination was confirmed and quantified (5 to 29%; SEC and FTIR). This gave a second method based on resin and PI, instead of crude extracts, accounting for low average molar mass PI (Mw) extracted by acetone instead of hexane. Both reference methods were used for calibrating NIRS applied to powdered biomass, with chemometric tools (PLS loadings, beta coefficients) to interpret spectral bands vs PI-resin relationship. ASE, not used before as reference, is highly reliable, and calibration with gravimetry (R² 0.96; 0.98; RPD 4.8; 4.6; for acetone and hexane extract) better than published data, thanks to the 215 samples covering genotypes, harvest date, plant age, climate. The method using cross contamination was less efficient because of higher experimental error induced by additional SEC and FTIR, and change in resin composition. Having set NIRS methods, a new protocol (single solvent THF, minimized processing, 20°C, fresh biomass) was designed to avoid degradation, yielding PI extracts with Mw above 2.106g/mole, closer to in vivo structure (6.105 when using dried guayule); caution to sample preparation in literature dealing with guayule PI structure. This calls for considering the complex structure of guayule biomass (PI in cells; resin in ducts; chemical instability) when extracting PI. These methods allowed producing high PI Mw glove and tire prototypes and domesticating this new crop in Europe within the EU-Pearls project. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://www.theses.fr/2012MON20210/document |
| Alternate Webpage(s) | http://agritrop.cirad.fr/573935/1/document_573935.pdf |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
