Screening method for differentiation of plastic and non-plastic microparticles contaminating store-bought rice

Abstract

This article presents a simple and low-cost screening method based on optical microscopy and FT-IR spectroscopy for assessing microparticles found in rice. Five brands of rice packed in paper and foil bags from both the European Union (EU) and non-EU region were tested. Microparticles of various shapes have been found in the rice regardless of the packaging type and origin of the rice. The content of microparticles varies depending on the sample, from 2 to even 12 items per 1 g of rice. Overall, the abundance of microparticles is higher in the case of rice packed in foil bags. Not all identified microparticles are microplastics, but those that are microplastics cannot be directly linked to the composition of the rice package. For a cursory analysis aimed at distinguishing the infrared spectra of non-plastic microparticles (i.e. rice, paper or cellulose) from microplastics, it is sufficient only to analyse the absorption bands above 2800 cm⁻¹.