Detection and quantification of microplastics in milk from Chandigarh, India: a pilot study highlighting SFEC-based spectral validation

Microplastics (MPs), defined as plastic particles less than 5 mm, have emerged as pervasive environmental contaminants increasingly reported in aquatic systems, air, and soil. Their detection in the human food chain has raised growing concerns regarding potential health risks. Although milk is a widely consumed dietary staple across all age groups, limited research has explored suitable methods for analysing MP contamination in this complex food matrix. In this study, a complementary multi-analytical framework was applied to investigate MP presence and characteristics in milk, integrating optical microscopy for initial screening with FTIR spectroscopy supported by an advanced spectral classification method (squared first-difference Euclidean cosine; SFEC) using the FloPP database, Raman spectroscopy for complementary polymer confirmation, and FESEM-EDX for morphological and elemental characterisation. To demonstrate these methods, milk samples (three commercial brands and one raw farm-sourced; <i>n</i> = 8) were analysed. MPs were detected in all samples, with concentrations ranging from 98 to 269 particles/L, showing diverse characteristics in colour, shape, and size. Polymers identified included PET, PU, PEVA, PE, PP, PC, PLA, rayon, and cotton fibres. These findings illustrate the feasibility of combining conventional spectroscopic techniques with advanced spectral matching to identify MPs reliably in dairy matrices. While the results provide preliminary evidence of MP occurrence in milk, larger-scale studies are needed for comprehensive risk assessment and source-tracking.