Identifying Microplastics in Tap Water Using Py-GC/MS

Researchers from the University of Missouri (Colombia, MO) have developed a cost-effective and streamlined pyrolysis gas chromatography-mass spectrometry (Py-GC/MS) methodology for the detection and quantification of microplastics in tap water, specifically focusing on seven common polymers. Whereas conventional approaches have relied on expensive pyrolyzate libraries, this method identifies pyrolysis fragments by matching m/z values with commercially available mass spectral libraries and confirms the findings using pure polymer standards. A paper based on their work has been published in MethodsX (1).

There has been an increase in public concern over the last decade regarding the contamination of environmental media such as water, soil, air, and even biota and human biological samples with microplastics. This is driven by evidence of the toxicity of microplastics as well as adverse impacts on the environment and public health (2-5). Py-GC/MS, focusing on the analysis of pyrolysis products or polymer degradation ions (m/z), has emerged as a reliable technique for the detection of microplastics across a variety of matrices, providing crucial data in terms of mass loading of microplastics in water (ng/L) or soil samples per volume (6,7). However, there are currently limited reports demonstrating the technique’s capabilities to accurately identify and quantify microplastics in some environmental media, such as tap water (8,9).

The authors of the study report that the performance of their method for the detection and quantification of seven polymers was rigorously validated through the evaluation of its linearity, sensitivity, selectivity, recovery, accuracy, and reproducibility. Specifically, the method was applied to quantify microplastics in tap water collected from laboratory sources in a campus building with the focus on quantification of those seven targeted polymers, and the test proved to be successful (1).

While the authors state that their method “provides a reliable, efficient, and cost-effective tool for routine laboratory analysis of microplastics in tap water and other environmental matrices,” they admit to limitations. These include the use of glass fiber filters as part of the filtration setup introduces a potential source of contamination, particularly for ABS polymer. As the method relies on precise calibration and consistent instrument performance, variations in pyrolysis conditions, such as furnace temperature, carrier gas flow rate, or column temperature programs, can affect the accuracy and reproducibility of results. Access to advanced Py-GC/MS equipment and commercially available mass spectral libraries, which may not be readily available in all laboratories, is necessary (1).

Woman filling a glass of water from a tap. © michaelheim- stock.adobe.com

References

1. Ccanccapa-Cartagena, A.; Gopakumar, A. N.; Salehi M. A Straightforward Py-GC/MS Methodology for Quantification of Microplastics in Tap Water. MethodsX 2025, 14, 103173. DOI: 10.1016/j.mex.2025.103173

2. Dehaut, A.; Hermabessiere, L.; Duflos, G. Microplastics Detection Using Pyrolysis-GC/MS-Based Methods, in Handbook of Microplastics in the Environment, T. Rocha-Santos, M.F. Costa, and C. Mouneyrac, Editors. 2022, Springer International Publishing: Cham. 141–175.

3. Beheshtimaal, A.; Alamdari, N.; Wang, B.; Kamali, M.; Salehi, M. Understanding the Dynamics of Microplastics Transport in Urban Stormwater Runoff: Implications for Pollution Control and Management. Environ. Pollut. 2024, 124302. DOI: 10.1016/j.envpol.2024.124302

4. Herath, A.; Datta, D. K.; Bonyadinejad, G.; Salehi, M. Partitioning of Heavy Metals in Sediments and Microplastics from Stormwater Runoff. Chemosphere 2023, 332, 138844. DOI: 10.1016/j.chemosphere.2023.138844

5. Yang, X.; Man, Y. B.; Wong, M. H.; Owen, R. B.; Chow, K. L. Environmental Health Impacts of Microplastics Exposure on Structural Organization Levels in the Human Body. Sci. Total Environ. 2022, 825, 154025. DOI: 10.1016/j.scitotenv.2022.154025

6. Hermabessiere, L.; Himber, C.; Boricaud, B.; Kazour, M.; Amara, R.; Cassone, A. L. et al. Optimization, Performance, and Application of a Pyrolysis-GC/MS Method for the Identification of Microplastics. Anal. Bioanal. Chem. 2018, 410, 6663-6676. DOI: 10.1007/s00216-018-1279-0

7. Gopakumar, A. N.; Ccanccapa‐Cartagena, A.; Bell, K., Salehi, M. Development of Crosslinked Polyvinyl Alcohol Nanofibrous Membrane for Microplastic Removal from Water. J. Appl. Polym. Sci. 2024, 141 (22), e55428. DOI: 10.1002/app.55428

8. Gomiero, A.; Øysæd, K. B.; Palmas, L.; Skogerbø, G. Application of GCMS-Pyrolysis to Estimate the Levels of Microplastics in a Drinking Water Supply System. J. Hazard. Mater. 2021, 416, 125708. DOI: 10.1016/j.jhazmat.2021.125708

9. Santos, L. H.; Insa, S.; Arxé, M.; Buttiglieri, G.; Rodríguez-Mozaz, S.; Barceló, D. Analysis of Microplastics in the Environment: Identification and Quantification of Trace Levels of Common Types of Plastic Polymers Using Pyrolysis-GC/MS. MethodsX 2023, 10, 102143. DOI: 10.1016/j.mex.2023.102143