Activated Persulfate Oxidation as Pretreatment for Quantification of Microplastics in Natural Water

The detrimental impact of microplastics (MPs) in natural water on human health and the environment has directed considerable attention toward the development of the corresponding quantification methods. However, the accurate quantification of MPs in natural water requires a meticulous sample pretreatment to distinguish them from other particulates. To address this need, we developed a rapid and simple pretreatment procedure based on heat- and base-activated persulfate oxidation, coupled with fluorescence microscopy. The pretreatment conditions were optimized by adjusting the reaction temperature and base concentration. The brief (15 min) persulfate treatment effectively degraded nonplastic microparticles (non-MPs) but minimally affected the physicochemical properties of polyethylene (PE)-MPs. Consequently, pretreating a mixture of PE-MPs and non-MPs in deionized (DI) water and various na…