Evaluating the Suitability of ATR-FTIR Spectroscopy for Screening Suspected Microplastics (MPs) in Human Breast Milk (HBM)

Abstract

Background: Microplastics (MPs) are increasingly detected in human biological samples, including human breast milk (HBM), raising concerns regarding infant exposure during early development. However, analysing MPs in HBM remains challenging due to its complex composition and limited standardised detection methods. This study aimed to evaluate the suitability of Attenuated Total Reflectance Fourier-Transform Infrared (ATR-FTIR) spectroscopy for identifying MPs in HBM following enzymatic digestion and oxidative treatment. Methods: Processed samples were filtered, visually screened under a stereomicroscope, and analysed using ATR-FTIR. Spectral matches were compared with a polymer reference library. Results: Several polymer signatures were detected, including polypropylene (PP), polyvinylidene fluoride (PVDF), and chlorosulfonated polyethylene (CSPE), with match scores ranging from low to moderate confidence (0.43–0.55). These findings show that ATR-FTIR can support preliminary MP screening in HBM, but accuracy is limited by spectral resolution, library constraints and contamination risks. Improved contamination control upgraded software libraries, and integration of complementary techniques such as Raman spectroscopy and pyrolysis-GC-MS are recommended to strengthen reliability. Conclusion: Overall, this work provides early analytical insight into MP detection in HBM and highlights key considerations for method optimisation in future studies.