Quantification and characterization of microplastics in surface water samples from the Northeast Atlantic Ocean using laser direct infrared imaging

• DOI: 10.1016/j.marpolbul.2023.114880
• Publication Date: 2023-04-07T02:52:05Z
• Authors: Jeannette Hansen; Lars Hildebrandt; Tristan Zimmermann; Fadi El Gareb; Elke Kerstin Fischer; Daniel Pröfrock
• Keywords: 13. Climate action; Polymers; Microplastics; Water; Plastics; Atlantic Ocean; 6. Clean water; Water Pollutants, Chemical; Environmental Monitoring

15 filtration samples were collected at eight locations onboard the RV Sonne (cruise SO279 in 2020) from 6 m water depth using a fractionated stainless-steel filtration unit. The size fraction > 300 μm was visually examined and potential microplastic particles were analyzed by ATR-FTIR spectroscopy. The treatment of size class 20 μm < d < 300 μm was based on enzymatic-oxidative microwave-assisted "one-pot" matrix digestion in conjunction with analysis of the microplastics by time-efficient LDIR imaging. Total number concentrations ranged from 47 to 2154 microplastic particles per m3 (average for all stations: 500 ± 700 microplastic particles m-3 (1 SD; n = 8)). In total, 20 polymer types were identified. The most common polymer types were polyethylene terephthalate (20 %) and acrylates/polyurethane/varnish (15 %). 93 % of the detected microplastics were smaller than 100 μm in length. Analysis of sample replicates indicates high spatio-temporal variations in microplastic pollution within the investigated region.