Evaluation of microplastics sediment sampling techniques—efficiency of common methods and new approaches

Abstract

Common sediment samplers for microplastics (MP) such as grab samplers or corers are limited to certain grain sizes and known to cause disruption of sediments which results in a loss of fine and low-density particles such as MP. However, this loss has not been quantified yet and its occurrence is commonly tolerated during MP sediment sampling. In the present study we evaluate the recovery of MP of various common sediment samplers used in most recent studies. The samplers were tested on a model plant simulating a riverine environment with MP spiked sediments. Also, we investigated the feasibility of less frequently used freeze coring. The results of this study suggest that a combination of common methods is crucial in order to sufficiently evaluate a sampling site until standardized MP samplers for sediments are available. Freeze coring indicates a promising potential to monitor MP in river sediments in the future but is costly and should be optimized for regular field sampling campaigns. Graphical Abstract