Identifying the origin of lignins and monitoring their structural changes by means of FTIR-PCA and -SIMCA

摘要: Abstract Lignins from sugarcane bagasse and eucalyptus, isolated respectively soda kraft liquors by precipitation with HCl or H 2 SO 4 , have been investigated together samples of lignins after organosolv pulping. Sugarcane lignin precipitated underwent oxidation O in aqueous NaOH. The reaction products, the oxidized (reprecipitated HCl) soluble products (isolated evaporation) formed two other groups samples. Fourier transform infra-red (FTIR) spectra 49 these KBr disks were recorded analysed principal component analysis (PCA) statistical isolinear multicomponent (SIMCA). After normalization dividing absorbance value at a certain wavenumber 1510 cm −1 PCA using 597 data points collected between 1950 800 showed that first components describe most total spectral variance. plot allowed to be grouped according their isolation (kraft, alkaline pulping organosolv), but no difference could observed when liquor . Furthermore, method allows very good separation acetylated can used as tool rapidly identify origin monitor structural changes.