We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Towards quality-assured measurements of microplastics in soil using fluorescence microscopy
AI summary Read the abstract
Researchers tested a fluorescence microscopy method with Nile Red staining for detecting microplastics in different soil types, achieving 80-90% recovery rates for particles larger than 500 micrometers. However, recovery dropped significantly for smaller particles and biodegradable plastics, particularly in clayey soils. The study developed a semi-automated image analysis pipeline and provides quality assurance guidelines for using fluorescence microscopy as a high-throughput microplastic detection method in soil research.
Fluorescence microscopy is increasingly seen as a fast, user-friendly, and high-throughput method for detecting microplastics (MPs) in soil; however, its effectiveness across diverse MP types and soil properties remains underexplored. This study tested a fluorescence microscopy-Nile red (NR) staining approach on eight MP types, covering both biodegradable and non-biodegradable plastics, in three size ranges (≤ 150 µm, 100-250 µm, 500-1000 µm) across loamy, clayey, and sandy soils. Each sample, processed in triplicate, underwent a relatively quick and straightforward extraction procedure involving density separation, organic digestion, and NR staining, followed by fluorescence and bright-field microscopy. A new digital image analysis pipeline using Image J was developed to expedite and (semi)automate MP quantification. Recoveries ranged from 80% to 90% for MPs with a Feret diameter of 500-1000 µm, regardless of soil type. In contrast, the recovery of smaller MPs (Feret dia. ≤ 250 µm) varied depending on the soils and plastic types: recoveries for low-density polyethylene (LDPE) reached 85% in sandy soil and 90% in loamy soil, whereas those for biodegradable polybutylene adipate terephthalate/polylactic acid (PBAT/PLA) were only 60% and 10%, respectively. The lowest recovery rate was observed in clayey soil and for biodegradable plastics. The method was tested on non-agricultural soil samples, yielding a MP mean number concentration of 20.7 ± 9.0 MPs/g for MPs sized from dia. ≥ 25 µm, comparable to Fourier transform infrared (FPA-µ-FTIR) results of 13.1 ± 7.3 MPs/g (p > 0.05). We conclude that fluorescence microscopy with NR staining and automated particle quantification offers a time-efficient, reproducible, and accurate method for MP detection in light-textured soils, whereas limitations remain for reliable MP analysis in clay-dominated soils.
More Papers Like This
Towards quality-assured measurements of microplastics in soils using fluorescence microscopy
AI summary Read the abstract
Researchers applied fluorescence microscopy with Nile Red staining to detect and measure microplastic particles in soil samples and validated the method across eight plastic types and a range of soil types. The method performed well when adapted to account for soil matrix effects. Validated fluorescence microscopy protocols make microplastic analysis in agricultural and environmental soils more accessible and standardized.
An economical fluorescent method for microplastic detection in soil samples
AI summary Read the abstract
A simplified low-cost Nile Red fluorescent staining method was developed for detecting microplastics in soil, validated on sand spiked with 1–5 mm microplastics, and designed for accessibility in educational settings and community monitoring programs without requiring expensive laboratory equipment.
An Economic Fluorescent Method for Microplastics Detection in Soil Samples
AI summary Read the abstract
Researchers developed a simplified, low-cost Nile red fluorescent dye method for detecting microplastics in soil samples, validating it on sand spiked with microplastics (1-5 mm) and achieving detection rates close to 100% using blue light illumination and orange filter glasses. Testing on urban lake sediment, agricultural soil, garden soil, and state park soil showed urban lake and garden samples had the highest microplastic densities, with the method suitable for educational outreach.
Detecting and monitoring the leaching of small (¡ 2 µm) microplastics in soils by fluorescence microscopy
AI summary Read the abstract
Researchers developed a fluorescence microscopy method to detect and monitor the leaching of small microplastics (under 2 µm) in soils, comparing it against µ-Raman spectroscopy across matrices of varying complexity and demonstrating its applicability for tracking the smallest microplastic fraction in soil systems.
Microplastic analysis in soils: A comparative assessment
AI summary Read the abstract
Researchers compared six different analytical methods for detecting and measuring microplastics in soil, testing them across different soil types and plastic materials. Fluorescence microscopy achieved the highest recovery rates for larger particles, while mass-based techniques like pyrolysis gas chromatography were better suited for detecting very small microplastics. The study highlights that no single method works best for all situations, and combining techniques may be necessary for accurate microplastic assessment in soil.
Research digests by email
When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.