Method validation of microplastics in food

It has been known that consumption of foods is an important pathway of microplastics intake in humans. Because of the complexity of food matrices, however, it is very difficult to develop standard experimental methods to isolate microplastics from foods and to identify them using spectroscopic methods such as Fourier-transform infrared spectroscopy. In this study, we optimized pretreatment methods for three representative food matrices–sea salts, soy sources, and salted fish eggs–representing dissolvable inorganic foods, liquid foods, and solid foods, respectively. Methods worked robustly in a laboratory in which the original methods have been optimized. For further validation of the methods, a small scale ring test was planned in five independent laboratories with different instruments. Standard microplastics of high-density polyethylene, polypropylene, polystyrene, polyethylene terephthalate, and polyamide 6 in …