Microplastic extraction from digestive tracts of large decapods

Authors

Katrina Bornt, University of Western AustraliaFollow
Kathryn Linge, ChemCentre
Jason How, Department of Primary Industries and Regional Development, Western AustraliaFollow
Simon de Lestang, Department of Primary Industries and Regional Development, Western AustraliaFollow
Renae Hovey, University of Western Australia
Tim J. Langlois, University of Western AustraliaFollow

Document Type

Article

Publication Date

9-2024

Journal Title

Marina Pollution Bulletin

ISSN

0025-326X

Keywords

Chitin; Crustacean; Plastic contamination; KOH method; Alkaline digestion; Density separation; DPIRD; WA

Abstract

The reliable quantification of microplastic contamination in chitinous organisms requires validated methods to remove interfering complex organic and inorganic material. This study trialled KOH, H2O2 and HNO3 digestion methods on the digestive tracts of two large decapods (Panulirus cygnus and Portunus armatus) to validate a protocol that facilitates reliable microplastic extraction. KOH digestion provided the best recovery (>95 %) of all polymers (e.g. polyamide, polyethylene, polyethylene terephthalate, polypropylene, polystyrene and polyvinyl chloride), with the lowest impact to their physical morphology and chemical spectra. While HNO3, and HNO3 + H2O2 treatments were more effective at digesting chitin, they destroyed polyamide, and altered several other polymers. High digestion efficiency did not result in high matrix clarification or high microplastic recovery for large decapods. This study emphasises the importance of validating species-specific microplastic extraction methods, whilst proposing additional post-digestion protocols, such as density separation, for complex samples, that can be applied in future research investigating plastic contamination in large decapods.

Comments

Highlights

• KOH provided best recovery of microplastics from digestive tracts of large decapods.

• High digestion efficiency (HNO3/H2O2) did not result in high polymer recovery.

• Specific method protocols depend on sample composition.

• Density separation is needed when digestive tracts contain sediment.

Recommended Citation

Bornt, K, Linge, K, How, J, de Lestang, S, Hovey, R, and Langlois, T J. (2024), Microplastic extraction from digestive tracts of large decapods. Marina Pollution Bulletin, 206 (116709).
https://library.dpird.wa.gov.au/fr_fja/258