Navigating Global Microplastics Regulations in Drinking Water with Vibrational Spectroscopy

Significance of the Topic

Access to safe and clean drinking water is essential for public health, yet microplastic contamination poses a growing environmental and health concern. Characterizing microplastics accurately is critical to inform regulations, protect consumers, and guide water treatment practices.

Study Objectives and Overview

This white paper reviews global regulatory frameworks for monitoring microplastics in drinking water and demonstrates how the Agilent 8700 LDIR chemical imaging system meets their requirements. It focuses on three key regulations: EU 2024/1441, California Water Boards policy, and ISO/DIS 16094-2, comparing their sampling, analytical, and reporting demands.

Methodology and Instrumentation

The primary microplastics analysis methods include thermo-analytical techniques (TED-GC/MS, pyrolysis-GC/MS) and vibrational spectroscopy (FTIR, Raman). This work emphasizes quantum cascade laser-based infrared microscopy implemented in the Agilent 8700 LDIR system. Sample collection employs large-volume filtration (up to 1,500 L) onto gold- or aluminum-coated filters or low-emissivity IR reflective slides. Quality control uses procedural blanks and fortified blanks per each regulatory protocol. The Agilent Cary 630 FTIR with diamond ATR enables identification of larger particles up to 5 mm.

Instrumentation Used

• Agilent 8700 LDIR chemical imaging system with QCL-IR and rapid scanning optics
• Agilent Clarity software with automated Particle Analysis workflow and microplastics spectral library
• Gold- and aluminum-coated filters (25 mm diameter) and low-emissivity IR reflective slides (25 × 75 mm)
• Agilent Cary 630 FTIR spectrometer with diamond ATR module for larger fragments

Main Results and Discussion

The Agilent 8700 LDIR system detects particles as small as 10 µm with high confidence (HQI > 0.95). Customizable size classifications align with regulatory categories (1–5 µm to 1,000–5,000 µm). Aspect ratio calculations and high-magnification imaging allow automated shape classification (fibers vs. fragments). Built-in spectral libraries cover major polymers (PE, PP, PET, PS, PVC, PA, PU, PMMA, PC, PTFE) and natural materials, ensuring reliable polymer identification. Automated blank measurements streamline QC, and end-of-run reports deliver counts per size fraction, polymer type, morphology, and images.

Benefits and Practical Applications

Implementing QCL-IR imaging offers significant advantages: accelerated throughput with fully automated workflows, reduced contamination risk through direct filter analysis, flexible data reporting that meets multiple regulatory standards, and high reproducibility across laboratories.

Future Trends and Potential Applications

Emerging standardization efforts (ISO/DIS 16094-2, ASTM WK87463) will further harmonize microplastics methods. Advances in spectral libraries, integration of thermo-analytical and vibrational data, and portable QCL-IR platforms may expand field monitoring. Machine learning for spectral matching and particle classification will enhance speed and accuracy.

Conclusion

The Agilent 8700 LDIR chemical imaging system, combined with robust software and QC procedures, satisfies current global regulations for microplastics in drinking water. Its rapid, automated, and sensitive analysis supports consistent compliance and informs strategies to manage emerging contaminants.

References

• ISO/DIS 16094-3. Water Quality — Analysis of Microplastic in Water. Part 3: Thermo-Analytical Methods for Waters with Low Content of Suspended Solids Including Drinking Water (accessed March 2025).
• Commission Delegated Decision (EU) 2024/1441. Supplementing Directive (EU) 2020/2184 by laying down a methodology to measure microplastics in water intended for human consumption (accessed March 2025).
• California Water Boards. Policy Handbook Establishing a Standard Method of Testing and Reporting of Microplastics in Drinking Water. SWB-MP1-rev1 (accessed March 2025).
• ISO/DIS 16094-2. Water Quality — Analysis of Microplastic in Water, Part 2: Vibrational Spectroscopy Methods for Waters with Low Content of Suspended Solids Including Drinking Water (under development; accessed March 2025).
• ASTM WK87463: New Test Method for Spectroscopic Identification and Quantification of Microplastic Particles in Water Using Infrared Spectroscopy (under development; accessed March 2025).
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