Additional Commentary on the Detection and Quantification of Plastic Micro- and Nanoparticles in Tea Samples.

Patricia Taladriz-Blanco,Alke Petri-Fink,Barbara Rothen-Rutishauser,Jessica Caldwell

doi:10.2533/chimia.2021.882

Patricia Taladriz-Blanco, Alke Petri-Fink + Show 2 more

Open Access

https://doi.org/10.2533/chimia.2021.882

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Abstract

The study of plastic particles, particularly those in the micro-, sub-micro-, and nano-size ranges, within food and beverages has gained increasing interest within recent years. However, many analytical techniques have limits of detection which hinder their use for the study of these particles in these sample matrices. In addition, remaining contaminants from the matrices can interfere with the signals from plastic particles. Thus, great care must be given to sample preparation and data interpretation to ensure accurate results. This study proposes the use of sample purification through chemical digestion protocols to facilitate the study of plastic particles present in tea samples, and serves to highlight technical limitations which must be overcome in future studies.

Highlights

Of the 368 million tons of plastics produced in 2020, 39.6%(approximately 145.7 million tons) were utilized in packaging materials.[1]
Many of the standard techniques utilized in the literature have limitations that hinder the accurate collection and interpretation of data; such as the limit of detection commonly reported for Fourier transform infrared spectroscopy (FTIR) being orders of magnitude larger (i.e. ~10 μm minimum particle size[6]) than the nanoplastic particles of interest or the difficulty differentiating true plastic particles from other organic materials in scanning electron microscopy (SEM) images.[7]. Such concerns have previously been expressed by Busse et al, who highlighted the potential for the results reported by Hernandez et al to be skewed by the presence of contaminants such as oligomers that would not be differentiated from true plastic particles by FTIR due to the area averaging quality of the measurements, or in SEM images due to oligomer crystallization upon drying.[7]
For the teabag types analyzed during the current study, it is likely that the leachate obtained from steeping the cut, rinsed commercial teabags is a mixture of plastic-based materials and other organic contaminants such as tea leaf-based particulate matter or dust

Summary

Introduction

(approximately 145.7 million tons) were utilized in packaging materials.[1] Such packaging is utilized to preserve food and beverage products meant for human consumption. Studies tend to focus on larger microplastic particle presence, and have reported their detection in a variety of food and beverage products such as bottled water[2] and beers.[3]. While this data serves to highlight the importance of quantifying the presence of plastic particles within products meant for human consumption, it fails to accurately represent the most analytically challenging fraction of plastic particles: nanoplastics

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