Automated PY-GCMS Workflow for the Qualitative and Quantitative Analysis of Microplastics in Environmental Samples

Significance of the Topic

Microplastics have become pervasive pollutants in aquatic and terrestrial environments, posing risks to ecosystems and human health. Reliable methods for identifying polymer types and quantifying their abundance are essential for monitoring contamination, assessing ecological impact, and guiding remediation efforts.

Objectives and Study Overview

This study evaluates an automated pyrolysis–gas chromatography/mass spectrometry (Py-GC/MS) workflow for both qualitative identification and quantitative measurement of microplastics. The approach integrates evolved gas analysis (EGA) and single‐shot pyrolysis to characterize major polymer classes commonly found in environmental samples.

Methodology and Instrumentation

• Sample Preparation: Solid polymer standards and environmental microplastic particles were ground or sliced to under 200 µg, placed into pyrolysis eco-cups with quartz wool.
• EGA-MS Analysis: Samples heated from 100 to 700 °C in the absence of a GC column to determine thermal decomposition zones.
• Single-Shot Pyrolysis GC-MS: Flash pyrolysis at an optimized temperature of 600 °C followed by separation on a Shimadzu GCMS-QP2020 NX and detection with QP2020 NX mass spectrometer.
• Data Analysis: Pyrolyzate peaks were matched against the F-Search library to identify characteristic compounds of common polymers.
• Instrumentation: Shimadzu GCMS-QP2020 NX, Frontier Lab multi-shot pyrolyzer (EGA/PY-3030D), auto-shot sampler.

Main Results and Discussion

EGA thermograms revealed distinct thermal zones for acrylonitrile-butadiene-styrene (ABS) and Nylon-6,6, guiding the selection of 600 °C for single-shot analysis. Seven target polymers (ABS, Nylon-6, Nylon-6,6, PET, PP, PS, PVC) were characterized by their signature pyrolyzates. Calibration curves prepared with polymer–CaCO3 standards over 0.20–4.00 mg exhibited excellent linearity (r² range 0.9947–1.0000). Precision tests (n=8) yielded percent RSD values between 2.63 % and 13.67 % across all polymers, demonstrating reproducibility.

Benefits and Practical Applications

• Rapid, robust workflow enables simultaneous qualitative and quantitative analysis of multiple polymer types.
• High sensitivity and precision support trace-level quantification of microplastics in complex matrices.
• Automated sampling and analysis reduce hands-on time and minimize contamination risk.
• Applicable to environmental monitoring, regulatory compliance, and industrial quality control.

Future Trends and Potential Applications

Advancements may include integration of higher-resolution mass spectrometry for enhanced polymer fingerprinting, expansion of spectral libraries for emerging polymer blends, and coupling with micro-extraction techniques for direct analysis of field samples. Development of standardized protocols will improve interlaboratory comparability. Portable or field-deployable pyrolysis systems could enable on-site monitoring of microplastic pollution.

Conclusion

The automated Py-GC/MS workflow using a Shimadzu GCMS-QP2020 NX coupled with a Frontier PY-3030D pyrolyzer provides a fast, accurate, and reproducible method for qualitative and quantitative analysis of common microplastic polymers. Calibration performance and precision metrics confirm its suitability for routine environmental and industrial applications.

References

• Owens A, Sandy A, Okamura Y, Marfil-Vega R. Automated PY-GCMS Workflow for the Qualitative and Quantitative Analysis of Microplastics in Environmental Samples. Shimadzu Scientific Instruments, Columbia, MD.