ИСТИНА

Microplastics are increasingly detected in diverse food matrices, raising questions regarding their reliable quantification [1–2]. Recent studies have reported the presence of small-size microplastics in agricultural and livestock products, such as milk, honey, and meat [3–5]. Among such products, chicken eggs represent a nutritionally valuable but analytically challenging biological matrix, combining lipid-rich yolk and protein based white, which complicates isolation and quantification of microplastics. Currently, there are no studies on the methodology of sample preparation of chicken eggs for microplastics. Thus, the aim of this study was to develop performance parameters for the quantitative determination of microplastics in chicken eggs using fluorescence microscopy as a reliable and sensitive method for small size microplastics. Several digestion protocols were tested to achieve effective degradation of eggs while preserving polymer particles. The most efficient protocol was found to be alkaline hydrolysis at elevated temperature, followed by neutralization of the digested egg solution. This procedure ensured minimal matrix interferences and high reproducibility of subsequent microplastics detection. For selective visualization, microplastics isolated from egg samples were stained with a commercially available fluorescent dye, enabling reliable recognition of polymer microparticles among other organic residues. The trueness of the proposed analytical method was assessed through several spike and recovery experiments. The developed approach was applied to eggs from several commercial producers. The results demonstrated that the proposed method provides accurate and reproducible quantification of microplastics in chicken eggs, presenting a valuable analytical tool for monitoring microplastic contamination in food products.