(°C) region remarks Commercial RT ester: ~171 ppm ~53 ppm Data Ms Lucie orange acid: ~175 ppm Pfaltzgraff pectin Enzymatic RT 172.8 ppm (very ~54 ppm The enzymatic treatment broad) treatment has 168.4 ppm (defined not removed all shoulder) the pectin 164.3 ppm (defined standalone peak) Enzymatic + 140 173.8 ppm (very weak and the impression Enzymatic + microwave broad) peaks exists that there microwave are no methyl treatment Hint for a shoulder ~ ester groups but seems to give 168 ppm but unclear there are clearly cleaner 180 173.8 ppm (broad but absent (or at some residual materials at smaller compared to maximum a carbonyl groups 140 °C 140 °C) shoulder) 168.3 ppm (distinct compared to peak) only microwave Microwave 140 173.6 ppm (broad broad peak at ~54 microwave treatment at treatment peak) ppm treatment at 140 140 °C 168.4 ppm (more C still leaves defined) some methyl Treatment at esters. 180 °C, 180 172.7 ppm (broad Absent microwave irrespective peak) treatment at 180 the exact 168.3 ppm (more C seems to have method, gives defined peak) eliminated all cleaner methyl esters. materials in Yet some which more carbonyl groups pectin has are remaining. been removed Note that the 13C solid state NMR spectra of all these materials are taken making that the should be bigger than the CO-O-CH3 peak. Table 6. Summary of CPMAS NMR signals of cellulose extracted by different methodologies based on the prior removal of pectin
(°C) region remarks Commercial orange pectin RT ester: ~171 ppm acid: ~175 ppm ~53 ppm Data Ms Lucie Pfaltzgraff Enzymatic treatment RT 172.8 ppm (very broad) 168.4 ppm (defined shoulder) 164.3 ppm (defined standalone peak) ~54 ppm The enzymatic treatment has not removed all the pectin Enzymatic + microwave 140 173.8 ppm (very broad) Hint for a shoulder ~ 168 ppm but unclear weak and peaks the impression exists that there are no methyl ester groups but there are clearly some residual carbonyl groups Enzymatic + microwave treatment seems to give cleaner materials at 140 °C compared to only microwave treatment at 140 °C Treatment at 180 °C, irrespective the exact method, gives cleaner materials in which more pectin has been removed Note that the 13C solid state NMR spectra of all these materials are taken making that the should be bigger than the CO-O-CH3 peak. 180 173.8 ppm (broad but smaller compared to 140 °C) 168.3 ppm (distinct peak) absent (or at maximum a shoulder) Microwave treatment 140 173.6 ppm (broad peak) 168.4 ppm (more defined) broad peak at ~54 ppm microwave treatment at 140 C still leaves some methyl esters. 180 172.7 ppm (broad peak) 168.3 ppm (more defined peak) Absent microwave treatment at 180 C seems to have eliminated all methyl esters. Yet some carbonyl groups are remaining. Table 6. Summary of CPMAS NMR signals of cellulose extracted by different methodologies based on the prior removal of pectin
Final%20Mres%20thesis%2010-06-2014.docx