Microplastics Analysis using Accelerated Solvent Extraction (ASE) and Pyrolysis Gas Chromatography / Mass Spectrometry (Pyr-GC/MS)

Analyzing Microplastics in the Environment
Oral Presentation

Prepared by C. Shevlin1, J. O'Brien2, C. Rauert3, K. Thomas3, E. Okoffo3
1 - Thermo Fisher Scientific, 490 Lakeside Dr, Sunnyvale, CA, 82801, United States
2 - PACE, The University of Queensland, 20 Cornwall St, Woolloongabba, QLD, 4102, Australia
3 - PACE, The University of Queensland, 20 Cornwall Street, Woolloongabba, QLD, 4102, Australia

Contact Information: [email protected]; 774-402-0647


Micro- and nano- sized plastics (MNPs) are considered contaminants of emerging concern for both environmental and human health due to their ubiquity and small size. Contamination of food and beverages intended for human consumption with plastics is poorly documented and human dietary cumulative exposure has not been exhaustively investigated. Assessing microplastic exposure levels in humans is important to understand the health consequences, which to date are mostly limited to in vitro studies4. To date, MNPs contamination has been reported in various foods and drinks. Rice is a staple food for more than half of the global population and it poses the highest food yield among the cereals providing >20% of the human dietary energy worldwide. In certain countries (e.g. Bangladesh and Cambodia) rice can constitute up to 70% of the dietary energy intake. Most of the rice available for consumers is packaged in plastic, but it is not known if packaging could be a contributing source of plastics.
Numerous rice cooking instructions direct consumers to wash the rice with tap water before cooking in order to remove the starchy coating, and this has been shown to reduce the heavy metal load. This washing process might also contribute to reducing the hypothetical plastic contamination. Rice is also sold pre-cooked, only requiring the consumer to microwave the rice inside the plastic packaging it is sold in. As a convenience food, it passes through several additional stages of industrial processing that could potentially lead to additional plastic contamination. Standardized mass concentration-based methods for the quantification of plastics in food are currently unavailable.

This work investigates plastic contamination in consumer rice products using a novel technique for plastics extraction and analysis in food. Rice samples were analyzed using a quantitative method consisting of Accelerated Solvent Extraction (ASE) followed by double-shot pyrolysis gas chromatography/mass spectrometry (Pyr-GC/MS) to estimate the mass concentration of selected plastic polymers in rice. The advantage of this methodology is that it is particle size independent and provides concentrations as a total mass of plastic per sample.