A practical approach based on FT-IR spectroscopy for identification of semi-synthetic and natural celluloses in microplastic investigation

Abstract In previous studies of marine debris or microplastics ( 2 O 2 and KOH) digestion treatments. The changes of 4 characteristic bands (1735, 1425/1419, 1105, 1060–1053/1030–1027 cm −1 ) were evaluated. We found that the band at 1105 cm −1 which is assigned to the C O antisymmetric in plane stretching band only existed in natural fibers even after the weathering and digestion treatments. The mixture of semi-synthetic and natural fibers from the real field samples was also easily distinguished using the characteristic band at 1105 cm −1 . Our results suggest that the characteristic band at 1105 cm −1 could be an ideal reference to distinguish natural and semi-synthetic fibers in field microplastic investigations. We also proposed a practical method to enhance the library of polymer spectra and improve the accuracy of semi-synthetic microplastic identification.