Microplastics Monitoring in Environmental Epipelagic Water

Significance of the Topic

Microplastics (MPs) have emerged as pervasive pollutants in epipelagic waters, posing risks to aquatic life and human health. Accurate monitoring from sample collection to polymer identification is essential for understanding distribution, assessing ecological impacts, and informing mitigation strategies.

Objectives and Study Overview

This application note presents a comprehensive workflow developed by Shimadzu for monitoring microplastics in environmental epipelagic water. The goals are to streamline sample preparation, achieve reproducible particle sizing, and provide reliable polymer characterization using integrated analytical instruments.

Methodology and Instrumentation

The monitoring workflow is organized into three main steps:

1. Sampling
   • Epipelagic water is collected using neuston nets from oceanic sites or manual grabs at river bridges following national guidelines.
2. Sample Preparation
   • Automated digestion and isolation of MPs using the MAP-100 Microplastic Automatic Preparation Device.
   • Removal of organic contaminants while preserving plastic fragments.
3. Analysis and Measurement
   • Size and morphology determination by stereoscopic microscopy (STZ-171-TLED) combined with Motic Images Plus software.
   • Polymer identification using the IRSpirit FTIR spectrophotometer with QATR-S ATR accessory and IR Pilot analysis wizard.
   • Support from a UV/heat-degraded plastic spectral database to enhance recognition of aged or weathered polymers.

Main Results and Discussion

The MAP-100 device efficiently digests biological material and isolates microplastics, reducing manual labor and improving reproducibility. Combining stereomicroscopy and image analysis allows accurate measurement of particle size distributions. FTIR analysis with the IRSpirit/QATR-S system reliably identifies polymer types, including UV- and heat-degraded fragments, by referencing a specialized database. This integrated approach ensures high data quality and traceability.

Benefits and Practical Applications

Key advantages of the Shimadzu workflow include:

• Labor savings through automation of tedious sample preparation steps.
• Enhanced reproducibility and safety by minimizing manual handling of reagents.
• Accurate particle sizing and robust polymer identification, critical for environmental monitoring and regulatory compliance.

This methodology supports research laboratories, quality assurance/quality control in environmental agencies, and industrial monitoring of marine pollution.

Future Trends and Application Opportunities

Emerging developments are likely to further improve microplastics analysis:

• Integration of Raman and infrared microspectroscopy for complementary polymer fingerprinting.
• Advanced image recognition and machine learning algorithms for automated particle classification.
• Portable and in situ instruments enabling field-based rapid assessments.
• Expansion of spectral libraries to cover a wider range of weathered and composite plastics.
• Coupling separation techniques (e.g., micro-FTIR with chromatography) for size-fractionated chemical analysis.

Conclusion

Shimadzu’s integrated suite of sampling tools, automated sample preparation, stereomicroscopy, and FTIR analysis provides a robust platform for monitoring microplastics in epipelagic waters. The workflow enhances efficiency, data quality, and reliability, supporting environmental research and pollution management efforts.