We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Evaluation of existing methods to extract microplastics from bivalve tissue: Adapted KOH digestion protocol improves filtration at single-digit pore size
Summary
Researchers compared several existing methods for extracting microplastics from bivalve tissue, including hydrogen peroxide, enzymatic digestion, and potassium hydroxide treatments. They found that only the KOH method allowed filtration through very fine filters down to 1.2 micrometers when a neutralization step was added, enabling recovery of much smaller microplastics. The study recommends KOH digestion as the most practical extraction method for studies aiming to assess human exposure risk from consuming shellfish.
Methods standardisation in microplastics research is needed. Apart from reagent-dependent effects on microplastics, varying target particle sizes can hinder result comparison between studies. Human health concerns warrant recovery of small microplastics. We compared existing techniques using hydrogen peroxide, Proteinase-K, Trypsin and potassium hydroxide to digest bivalve tissue. Filterability, digestion efficacy, recoverability of microplastics and subsequent polymer identification using Raman spectroscopy and a matching software were assessed. Only KOH allowed filtration at ≤25 μm. When adding a neutralisation step prior to filtration, KOH digestates were filterable using 1.2-μm filters. Digestion efficacies were >95.0% for oysters, but lower for clams. KOH destroyed rayon at 60 °C but not at 40 °C. Acrylic fibre identification was affected due to changes in Raman spectra peaks. Despite those effects, we recommend KOH as the most viable extraction method for exposure risk studies, due to microplastics recovery from bivalve tissues of single-digit micrometre size.
Sign in to start a discussion.