Conventional Methods for Carboxyl Analysis in Cellulose

Crystal violet base Acid-base reaction in benzene Photometric [120] 

Problems frequently encountered with the above described methods are  

For a recent review on a critical evaluation on classical methods see Fardim et al. [123]. In addition to the wet chemical methods, FTIR spectroscopy and ESCA [124,125] techniques have been applied to quantify carboxyl groups in cellulose and pulp. In case of FTIR, satisfactory results in comparison to wet chemical analysis could only be obtained with carboxyl-rich samples [ 126— 128], 

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