When every particle matters: A QuEChERS approach to extract microplastics from environmental samples

The identification of microplastics (MP), especially small (<500 μm) MP, using automated surface-chemistry approaches requires the best possible reduction of natural particles whilst preserving the integrity of the targeted synthetic polymers particles. In general, both natural and synthetic particles can be highly diverse physically and chemically and MP extraction, particularly from complex matrices such as sediments, sludge and soils, requires efficient method pipelines. Our paper presents a universal framework of modular protocols (presented in a decision tree) that fulfil predefined user requirements (QuEChERS: Quick, Easy, Cheap, Effective, Rugged, Safe) as well as providing best practises for reasonable MP working conditions within a standard laboratory. New procedures and technical innovations for density separation of particle-rich matrices are presented, such as a spiral conveyor developed and validated for MP recovery. In sharing such best-practice protocols, we aim to help in the push towards MP quantification method standardisation. • Publication of protocols of an entire MP extraction (10 μm – 5 mm) pipeline for particle-based analysis of various environmental matrices; • Modularity: Optimised quantitative sample preparation adapted to particle sizes and sample matrices; • New protocols and technical innovations (e.g. spiral conveyor) optimise MP extraction.