Microplastics and nanoplastics in food, water, and beverages, part II. Methods

Since microplastics (MPs) and nanoplastics (NPs) have started emerging as ubiquitous contaminants in the environment, a variety of analytical techniques has been developed and tested for the detection and characterization of polymer particles at a micro- and nano-scale. Yet, no unique method stands out for its ability to yield all the relevant information required to properly address MP and NP contamination in the environment, and even less so in food material. In this review, several approaches to sample preparation and isolation of MPs from food matrices are reported, well-established and promising emerging analytical techniques for the detection and characterization of MPs and NPs are described and discussed. The information reported in this review shows that even the most widely used methods are still under development and MP/NP analysis is still far away from method validation and standardization. The establishment of rigorous best practices to yield reliable data and build a comprehensive knowledge of MP and NP occurrence in food is essential for the implementation of strategies and policies to address MP/NP pollution. Therefore, an outlook of the field towards harmonization and quality improvement of MP/NP analysis is included in this review.