Lessons learned from an intercalibration exercise on the quantification and characterisation of microplastic particles in sediment and water samples

An intercalibration exercise on the characterisation of microplastics in marine sediment and water samples was carried out among five laboratories involved in the implementation of the Marine Strategy Framework Directive (MSFD) in their country. The samples were prepared by mixing cleaned natural sediment and sea water with microplastics sets made of particles of various polymers, shapes and colours. Overall, the errors on total counts were under 25% in absolute value. The risk of non-detection and loss of particles is greater than the risk of contamination during sample analysis. Significant differences are observed among particle types. It appears difficult to obtain reliable and comparable data on the colour of microplastics. A comparison of the errors with regards to the protocols used led to recommend NaCl [1.2 g/cm3] density separation for sediment and one filtering step (200 μm). The operators' experience appears as a key factor for the quality of the results

Lessons learned from an intercalibration exercise on the quantification and characterisation of microplastic particles in sediment and water samples

An intercalibration exercise on the characterisation of microplastics in marine sediment and water samples was carried out among five laboratories involved in the implementation of the Marine Strategy Framework Directive (MSFD) in their country. The samples were prepared by mixing cleaned natural sediment and sea water with microplastics sets made of particles of various polymers, shapes and colours. Overall, the errors on total counts were under 25% in absolute value. The risk of non-detection and loss of particles is greater than the risk of contamination during sample analysis. Significant differences are observed among particle types. It appears difficult to obtain reliable and comparable data on the colour of microplastics. A comparison of the errors with regards to the protocols used led to recommend NaCl [1.2 g/cm3] density separation for sediment and one filtering step (200 μm). The operators' experience appears as a key factor for the quality of the results

Interlaboratory comparison of microplastic extraction methods from marine biota tissues: A harmonization exercise of the Plastic Busters MPAs project

In the framework of the Plastic Busters MPAs project, a harmonization exercise on two methods of microplastic extraction from biological samples i.e. 15% H2O2 digestion and 10% KOH digestion was carried out. The two methods were tested in four laboratories on fish gastrointestinal tracts and mussel tissues spiked with polyethylene, polypropylene and polyethylene terephthalate. The recovery percentage of microplastics for each method, species and polymer tested were overall similar among laboratories, and interlaboratory coefficient of variation was less than 11% for the majority of samples. Microplastic recovery rates for the two methods were similar for each sample tested, but overall mean interlaboratory recovery rate using KOH (96.67%) was higher than H2O2 (88.75%). Results validate the use of both methods for extracting microplastics from biota tissues. However, when comparing the two methods in terms of microplastic recovery rate, time consumed, technical difficulties and cost, digestion with 10% KOH is considered optimal.En prensa2,35