Discrimination between virgin and recycled polystyrene containers by Fourier transform infrared spectroscopy and principal component analysis

• Published in: Packaging technology & science Vol. 31; no. 8; pp. 567 - 572
• Main Authors: Song, Xue‐Chao, Lin, Qin‐Bao, Chen, Chao‐Fang, Chen, Jing‐Hong, Hu, Chang‐Ying
• Format: Journal Article
• Language: English
• Published: Bognor Regis Wiley Subscription Services, Inc 01.08.2018
• Subjects: Carbonyl compounds; Carbonyls; Chemometrics; Containers; Discrimination; Fourier transforms; FTIR; Infrared analysis; Infrared spectroscopy; Organic chemistry; PCA; Polymers; Polystyrene resins; Principal components analysis; Quality control; recycled polystyrene; Spectroscopic analysis; Spectrum analysis
• ISSN: 0894-3214; 1099-1522
• DOI: 10.1002/pts.2378

A rapid and reliable method for discriminating virgin and recycled expanded polystyrene (EPS) containers was developed using Fourier transform infrared spectroscopy combined with principal component analysis. Standard normal variate, first and second‐order derivative spectra were compared for the discrimination results. The results show that carbonyl region (1780‐1620 cm−1) spectra using first derivative transformation give the optimum classification results. In addition, the carbonyl compounds in EPS containers were detected to clarify the chemical difference between virgin and recycled containers, with a higher concentration of carbonyl compounds observed in recycled EPS containers. The combination of carbonyl region of Fourier transform infrared spectroscopy with chemometrics proved to be a promising method to discriminate virgin and recycled EPS containers, which could function as an additional tool for quality control of plastics. Fourier transform infrared spectroscopy combined with principal component analysis (PCA) after first derivative pre‐treatment was used to discriminate virgin and recycled expanded polystyrene (EPS) food containers. The degradation occurring in the recycling process would lead to an increase of the absorbance in carbonyl region (1780–1620 cm−1), which could serve as variables for building PCA model.