Highlights from a review of microplastics in marine sediments

A screening-level human health risk assessment for microplastics and organic contaminants in near-shore marine environments in American Samoa

“…For example, studies of microplastics in seawater in the United Kingdom with 5µm sized filters found an average of only 1.5 to 6.7 particles per liter (Li et al 2018), while other studies with much larger sample sizes (e.g. more water filtered) over larger spatial scales and with larger 300 µm pore-sized nets found between 8 to 9200 particles/m 3 (or 0.008 to 9.2 particles per liter) (Desforges et al 2014)., Given the low numbers of microplastics detected in marine sediments in our study, potential issues with the selected extraction methods cannot be ruled out (Cashman et al 2020, Phuong et al 2021. In a systematic review of 70 studies of microplastics extracted from marine sediments, Phoung et al (2021) found that only 22 reported method recovery rates.…”

Selection of a density separation solution to study microplastics in tropical riverine sediment

“…In general, the process used to determine MP concentrations in sediment samples comprises extraction, separation, identification and quantification (Shim et al, 2017). Several methods have been developed for MP extraction from marine and beach sediment samples, including filtration, sieving, density separation, flotation, chemical decomposition, electrostatic separation, elutriation column optimisation and magnetic extraction using coated Fe nanoparticles to magnetise plastics (Felsing et al, 2018;Grbic et al, 2019;Hengstmann et al, 2018;Hidalgo-Ruz et al, 2012;Müller et al, 2020;Nakajima et al, 2019;Phuong et al, 2021). However, density separation is the most commonly applied method for isolating MPs from sediment and is based on the specific density difference between MPs and sediments to separate less dense plastic polymers from denser sediment particles (Coppock et al, 2017;Phuong et al, 2021).…”

“…Several methods have been developed for MP extraction from marine and beach sediment samples, including filtration, sieving, density separation, flotation, chemical decomposition, electrostatic separation, elutriation column optimisation and magnetic extraction using coated Fe nanoparticles to magnetise plastics (Felsing et al, 2018;Grbic et al, 2019;Hengstmann et al, 2018;Hidalgo-Ruz et al, 2012;Müller et al, 2020;Nakajima et al, 2019;Phuong et al, 2021). However, density separation is the most commonly applied method for isolating MPs from sediment and is based on the specific density difference between MPs and sediments to separate less dense plastic polymers from denser sediment particles (Coppock et al, 2017;Phuong et al, 2021). Various density salt solutions have been used to extract MPs from marine sediment samples, and a wide range of recovery efficiencies have been found when using single or combined salt solutions for the extraction of MPs within the same environmental compartment (Claessens et al, 2013;Nuelle et al, 2014;Quinn et al, 2017).…”

Latest Advances and Developments to Detection of Micro‐ and Nanoplastics Using Surface‐Enhanced Raman Spectroscopy

“…According to the studies reviewed in this work, the preparation of the reported SERS substrates shows that each one was designed for a specific type of sample, which indicates a lack of standardization in the detection method of micro‐ and nanoplastics with SERS. [ 139 ] On this subject, Sharma et al have stated that it is challenging to compare various SERS substrates due to the complexity to rigorously characterize them. Furthermore, they provided a list of factors that must be considered to classify a material as reliable and highly enhancing for SERS.…”