Characteristics of microplastic-derived dissolved organic matter and its binding with pharmaceuticals unveiled by fluorescence spectroscopy and two-dimensional correlation spectroscopy

作者：Caixia Yan, Wang Xiao, Minghua Nie, Xi-Ting Mo, Mingjun Ding, Jie Chen, Yi Yang · 发表于：The Science of The Total Environment · 年份：2023 · DOI：10.1016/j.scitotenv.2023.168190 · 被引用次数：49 · 研究领域：Microplastics and Plastic Pollution、Pharmaceutical and Antibiotic Environmental Impacts、Analytical chemistry methods development

Microplastics were an extensively detected pollutant in the environment, but microplastic-derived dissolved organic matter (MP-DOM) has received less attention, much less its impact on the binding behavior of pollutants ( e.g. , pharmaceuticals). In this study, DOM derived from two typical MPs, i.e. , polyethylene terephthalate (PET) and polystyrene (PS) was generated by UV irradiation (a widely used way for MPs' aging treatment) and characterized by multiple spectroscopic techniques and methods. Chloramphenicol (CAP) and carbamazepine (CBZ) were selected to investigate the binding mechanism between MP-DOM and pharmaceuticals. After UV irradiation, the concentration of the dissolved organic carbon , colored DOM, and carboxyl/carbonyl groups of MP-DOM increased. Moreover, the humic-like substance released preceding and more under UV irradiation. Furthermore, the protein-like substances on PET-DOM and the humic-like substances on PS-DOM were positively correlated to the binding capacity to the pharmaceuticals, respectively. 2D-COS results revealed that the fluorescent materials having more oxygen-containing functional groups for MP-DOM preferentially interacted with the pharmaceuticals. Overall, the higher fluorescence quenching was related to the protein-like substance, CBZ, and PET-DOM as compared to the humic-like substance, CAP, and PS-DOM. It was verified by the relatively high binding ability (log K M ) for them (the protein-like substance: 5.15; CBZ: 4.61; PET: 4.48). Th...