Assessment of cellulose structural variety from different origins using near infrared spectroscopy

Near infrared (NIR) spectroscopy was tested as a rapid monitor of cellulose features by analyzing structurally distinguishable cellulose from different organisms ranging from Monera to Plantae as well as Animalia. The optimal spectral region was first identified using intra-crystalline deuteration, and then statistically analyzed based on second derivative spectra by principal component analysis. The score plots clearly distributed the samples according to crystalline structure such as relative crystallinity and allomorphism. These characteristics and the corresponding loading factors provided key NIR absorption criteria for identifying structural properties, especially in bands at 6527 and 6383 cm(-1), which correspond to I-alpha and I-beta, respectively. In addition, calibration models were created for relative cellulose crystallinity using partial least square regression and for allomorph ratios using simple absorption band shifts at 6476-6446 cm(-1). NIR spectra of cellulose from various organisms combined with multivariate analysis can be used as a database for simple and rapid assessment of unknown cellulose materials.