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Updated: Jul 10, 2025
Protocol for Microplastics Sampling on the Sea Surface and Sample Analysis
Published on: December 16, 2016
Detecting small microplastics down to 1.3 μm using large area ATR-FTIR.
Yuanli Liu1, Stephan Lüttjohann2, Alvise Vianello3
1Department of the Built Environment, Aalborg University, Thomas Manns Vej 23, 9220 Aalborg, Denmark; College of Environmental and Biological Engineering, Putian University, Putian 351100, China; Fujian Provincial Key Laboratory of Ecology-Toxicological Effects and Control for Emerging Contaminants, Putian University, Putian 351100, China; Key Laboratory of Ecological Environment and Information Atlas, Fujian Provincial University, Putian 351100, Fujian, China.
Large area attenuated total reflectance-Fourier transform infrared spectroscopy (LAATR-FTIR) effectively detects small microplastics (MPs) down to 1.3 μm. While promising for small particles, LAATR-FTIR struggles with larger MPs, offering complementary data to traditional methods.
Area of Science:
- Environmental Science
- Analytical Chemistry
- Spectroscopy
Background:
- Microplastic (MP) pollution is a growing environmental concern.
- Accurate detection and characterization of MPs, especially small ones, remain challenging.
- Fourier transform infrared spectroscopy (FTIR) is a key technique for MP identification.
Purpose of the Study:
- To introduce and evaluate Large Area Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (LAATR-FTIR) for microplastic detection.
- To compare the performance of LAATR-FTIR with traditional transmission mode micro-Fourier Transform Infrared Spectroscopy (μ-FTIR).
- To assess the capability of LAATR-FTIR in identifying small microplastics in environmental samples.
Main Methods:
- Utilized two LAATR-FTIR units with Zinc Selenide (ZnSe) and Germanium (Ge) crystals.
- Tested with reference microplastics (< 20 μm) and microplastics in marine water samples.
- Compared spectral data quality and particle identification with μ-FTIR in transmission mode.
Main Results:
- LAATR-FTIR successfully detected small microplastics down to 1.3 μm.
- The technique showed limitations with larger microplastics due to uneven particle-crystal contact.
- Spectral quality in LAATR mode was comparable to transmission mode.
- LAATR-FTIR provided valuable additional information on small microplastics.
Conclusions:
- LAATR-FTIR is a promising technique for detecting small microplastics, complementing traditional methods.
- The technique is well-suited for homogeneous matrices but faces challenges with heterogeneous samples.
- While not a complete replacement for transmission mode, LAATR-FTIR offers unique advantages for microplastic analysis.
