Evaluation Method for Microplastics Deterioration Degree Using UV-Irradiated Polyethylene Model Sample

• Published in: BUNSEKI KAGAKU Vol. 71; no. 10.11; pp. 589 - 593
• Main Authors: KATAOKA, Hiroki, YUKIOKA, Satoru, TANAKA, Shuhei, TAKAO, Kazuya, IKUTA, Kumiko, MATSUMOTO, Yoshinori
• Format: Journal Article
• Language: English; Japanese
• Published: Tokyo The Japan Society for Analytical Chemistry 01.01.2022; Japan Science and Technology Agency
• Subjects: Carbonyls; Deterioration; Fourier transforms; FT-IR; hardness; Infrared analysis; Infrared spectroscopy; Microhardness; microplastics; polyethylene; Polyethylenes; SEC; Size exclusion chromatography
• ISSN: 0525-1931
• DOI: 10.2116/bunsekikagaku.71.589

In recent years, microplastics (MPs) have come to be recognized as a threat to the environment, and research studies underway to elucidate the mechanism of MPs generation in the environment. Understanding the deterioration state of MPs in the environment is necessary to suppress the outflow of MPs. However a method for investigating the deterioration state has not been established. Since MPs are trace and minute samples, there are few methods for analyzing deterioration state. We developed deterioration state analysis method using Fourier Transform Infrared Spectroscopy (FT-IR), Size Exclusion Chromatography (SEC) and a micro hardness tester. In this study, we evaluated the carbonyl index, molecular weight and hardness of UV-irradiated polyethylene model samples, and used these for a deterioration index. We estimated the years of outdoor exposure of MPs collected from the environment by comparing the evaluation results of MPs with the deterioration index.