Use and misuse of FTIR spectroscopy for studying the bio-oxidation of plastics

Due to massive production, inefficient waste collection, and long lives, plastics have become a source of persistent pollution. Biodegradation is explored as an environmentally friendly remediation method for removing plastics from the environment. Microbial and animal biodegradation methods have been reported in the literature for various plastics. Levels of plastic oxidation are often used as an evidence of degradation and can be measured with great sensitivity by Fourier Transform Infrared (FTIR) spec-troscopy. FTIR is highly sensitive to the creation of new C-O, C=O and O-H bonds during oxidation. However, many studies reporting the use of FTIR spectroscopy to evidence plastic oxidation confused the spectral signatures of biomass contamination (C-O and C=O from lipids, CONH from proteins, O-H from polysaccharides) with plastic oxidation. Here, based on spectra of oxidized plastic and of probable contaminants, we make recommendations for performing and analyzing FTIR measurements properly. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

Plastics have become a persistent source of pollution due to massive production and long lives, while biodegradation is explored as an environmentally friendly remediation method. Using FTIR spectroscopy to measure the oxidation levels of plastics requires careful consideration of potential biomass contamination.