Article
?
AI-assigned paper type based on the abstract. Classification may not be perfect — flag errors using the feedback button.
Tier 2
?
Original research — experimental, observational, or case-control study. Direct primary evidence.
Nanoplastics
Sign in to save
Extracting and characterizing microplastics and nanoplastics from environmental samples
Nature Protocols2025
2 citations
?
Citation count from OpenAlex, updated daily. May differ slightly from the publisher's own count.
Score: 48
?
0–100 AI score estimating relevance to the microplastics field. Papers below 30 are filtered from public browse.
Researchers developed a standardized four-step extraction method for isolating and characterizing microplastics and nanoplastics from diverse environmental samples, encompassing predigestion, density separation, postdigestion, and postdensity separation steps to improve cross-study comparability.
There is increasing interest in measuring the effect of microplastics and nanoplastics (MNPs) in the environment, but it is difficult to compare the results obtained in these studies due to variations in the extraction and characterization techniques, as well as the variability of the matrices analyzed. Here we provide a workflow consisting of three separate procedures for (1) preprocessing of different environmental samples, (2) methods for MNP extraction (four-step extraction method) and (3) techniques for qualitative and quantitative characterization of MNPs. The four-step extraction method (FSEM) involves predigestion, predensity separation, postdigestion and postdensity separation. This process has been optimized to maximize recovery (between 83.7% and 100% for polyethylene, polyethylene terephthalate, polypropylene, polystyrene and polymethyl methacrylate) and purity while minimizing artefactual changes to the particles. It is crucial to characterize the MNPs extracted using the FSEM to understand their chemical composition and other physicochemical properties such as quantity, particle size and morphology. We provide guidance on the use of different fit-for-purpose analytical technologies, including attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), laser direct infrared spectroscopy (LDIR) and optical photothermal infrared microspectroscopy (O-PTIR). These techniques can be combined to characterize MNPs with particle sizes of 0.5-5,000 µm. We provide advice on how to optimize the sample preparation methods by adding or removing extraction steps based on the complexity of the matrix and purpose of the analysis. The suggested validation workflow also uses additional analytical techniques (for example, atomic force microscopy and flow cytometry) to evaluate efficiency, feasibility and reliability. We provide experimental detail for analysis using micro-FTIR, which can be used instead of LDIR and O-PTIR to characterize microplastics with particle sizes larger than 10 µm. Execution of this workflow takes 7-30 d and can be performed by researchers, technicians and students in the environmental field if they have access to the required equipment.