Rapid optimization of decapod crustacean digestion for efficient microplastic extraction (MPs)

The objective of this study was to develop and apply a rapid digestion protocol for extracting microplastics (MPs) from commercial crab samples using four different digestion methods. The methods employed included thermo alkaline digestion with potassium hydroxide (KOH), oxidative digestion with hydrogen peroxide (H2O2), enzymatic digestion with protease, and digestion using the surfactant dodecyl dimethyl betaine (DDB). Among these, protocols 2 and 4 (P2 and P4) achieved efficient digestion rates of 93% and 96%, respectively. These protocols were validated based on recovery percentage, repeatability, color assessment, and the chemical integrity of the MPs. The MPs extracted were analyzed using optical microscopy, revealing their presence in the forms of fibers, films, and fragments. Additionally, MPs were characterized by Fourier transform infrared spectroscopy in attenuated total reflectance mode (FTIR-ATR), with spectral quality indices (Q) ranging from 0.82 to 0.90.