Analysis of Microplastics in Environmental Water Using Microplastic Automatic Preparation Device MAP-100 and FTIR

Significance of the Topic

Microplastic contamination in rivers and oceans poses a growing threat to ecosystems and human health. Reliable detection and characterization of microplastics demand robust sample preparation and analytical methods. Automating labor-intensive pretreatment steps can improve data quality, reproducibility and analyst safety.

Objectives and Study Overview

This study demonstrates the integration of a Microplastic Automatic Preparation Device (MAP-100) with a Fourier Transform Infrared Spectrophotometer (FTIR) to analyze microplastics in environmental surface water. The goal was to streamline sample preparation, remove interfering contaminants and accurately identify plastic types using an infrared spectral library.

Methodology and Instrumentation

The workflow comprises four automated steps:

• Screening: Sieving to retain particles from 0.3 to 5 mm
• Digestion: Oxidation of organic matter with 30% hydrogen peroxide over three days
• Separation: Density sorting of inorganic debris using 5.3 mol/L sodium iodide solution for three hours
• Filtration: Collection of isolated microplastics on a membrane filter

Automated control software manages reagent addition, timing and process monitoring in real time, reducing manual handling and safety risks.

Instrumentation Used

• MAP-100 Microplastic Automatic Preparation Device
• IRSpirit-T FTIR Spectrophotometer
• QATR-S Diamond ATR Accessory
• UV-Damaged Plastics Library (Shimadzu proprietary database)

Key Results and Discussion

Surface water samples from a river in Okinawa Prefecture were processed with the MAP-100. Visual inspection confirmed effective removal of organic and inorganic contaminants. Infrared spectra acquired by FTIR produced high-quality matches against library entries:

• Sample A: Polypropylene degraded by UV for 25 hours (match score 876)
• Sample B: Polyethylene degraded by UV for 550 hours (match score 904)

High matching scores reflect the device’s ability to generate clean spectra by eliminating background interference.

Advantages and Practical Applications

• Labor savings: Automation frees analysts from repetitive manual steps
• Enhanced repeatability: Software-controlled protocols ensure consistent preparation
• Improved safety: Enclosed handling of corrosive reagents minimizes exposure
• Accurate identification: Clean sample matrices yield reliable FTIR spectral matches

These benefits support routine monitoring programs and research applications in environmental analytics, quality control and regulatory compliance.

Future Trends and Opportunities

Advancements may include:

• Extension to smaller particle sizes below 0.3 mm
• Integration of imaging and automated microscopy for particle sizing
• Expanded spectral libraries covering emerging polymer blends and additives
• On-site or portable systems for real-time environmental monitoring
• High-throughput workflows coupling preparation and spectral mapping

Conclusion

The combination of the MAP-100 automatic preparation device and FTIR analysis enables efficient, reproducible and safe workflows for microplastic detection in environmental waters. The automated removal of contaminants improves spectral quality and identification accuracy, making this approach a valuable tool for environmental monitoring and research.

Reference

Shimadzu Application News No. A647 (2023) – Analysis of UV-Damaged Plastics Library by FTIR