Extractable Pollutants from Microplastics to Vegetables: Incorporation to the Food Chain

Importance of the Topic

Microplastics are emerging pollutants in terrestrial ecosystems, capable of releasing additives and degradation products that may be taken up by crops and enter the human food chain. While their impact in marine environments has been widely studied, the migration of plastic-related volatiles into vegetables remains poorly understood. A sensitive, rapid and robust analytical approach is needed to monitor these compounds and support food safety assessments.

Objectives and Study Overview

This study aimed to develop and validate a static headspace gas chromatography/mass spectrometry (SHS-GC/MS) method to screen, identify and quantify volatile organic compounds leached from microplastics into vegetables. Key goals were:

• To apply targeted and untargeted SHS-GC/MS for plastic-related volatiles in edible- and nonedible-root vegetables.
• To assess differences in compound profiles between root types.
• To demonstrate method performance (linearity, detection limits, precision, recovery).
• To provide evidence of polymer-specific contamination in agricultural produce.

Methodology and Instrumentation

Vegetable samples (38 items, 114 analyses) were homogenized, spiked with internal standards (toluene, naphthalene) and subjected to SHS extraction (3 g sample, 130 °C, 35 min). Headspace gas (2 mL) was injected in split mode (10:1) to an Agilent 8890 GC coupled with a 5977B GC/MSD operated in full-scan and SIM modes. A two-column setup (HP-5ms, 15 m×0.25 mm×0.25 µm each) with pneumatic switching provided separation. Method development optimized incubation parameters, sample mass, temperature program and injection volume. Spectral deconvolution and retention indices (MS-DIAL) supported compound identification.

Instrumentation Used

• Gerstel MPS with static headspace sampler.
• Agilent 8890 GC with 5977B MSD (EI source).
• Agilent J&W HP-5ms columns and purged ultimate union (PUU).
• Pneumatic switching device (PSD) for mid-column flow control.

Main Results and Discussion

Untargeted analysis identified 92 volatiles, including additives and degradation markers associated with PS, PVC, PET and PC. Principal component analysis and OPLS-DA discriminated edible- from nonedible-root vegetables, revealing higher levels of alkylphenols (2,4-di-tert-butylphenol, 2,4-dimethylphenol, 2-tert-butyl-4-methylphenol) and cumene in edible-roots. Phenylacetaldehyde and styrene—PS degradation markers—were detected in >80% of samples. Xylene isomers and ethylbenzene indicated PVC/PET contamination. Targeted quantification achieved limits of detection from 0.03 to 15 ng/g, LOQs from 0.1 to 50 ng/g, interday precision <13% RSD and recoveries of 90–110%. Concentrations ranged from sub-ng/g to tens of µg/g across vegetables.

Benefits and Practical Applications of the Method

The SHS-GC/MS approach offers automated sample preparation, low solvent consumption and minimal matrix interference. It enables routine screening of large sample sets for volatile plastic leachates, supporting laboratory QA/QC, environmental monitoring and risk assessment in food safety.

Future Trends and Potential Applications

Further work may extend this method to other crops, soils and processed foods, integrate liquid chromatography for less volatile additives, and employ high-resolution MS for non-volatile leachates. Combining isotopic labeling and multimodal analytics will advance understanding of microplastic fate and inform regulatory guidelines.

Conclusion

An SHS-GC/MS protocol using Agilent instrumentation was established for comprehensive detection and quantification of volatile microplastic-related compounds in vegetables. The study demonstrated clear polymer-specific contamination patterns, especially in edible-root crops, and provided a validated tool for food chain monitoring.

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