FTIR assessment of PFAS phytoremediation by Cannabis sativa L. for sustainable water treatment

Efficient and sustainable analytical strategies are fundamental to mitigate the environmental impacts of per- and polyfluoroalkyl substances (PFAS), persistent contaminants characterized by strong chemical stability and resistance to conventional remediation processes. Cannabis sativa L. (C. sativa), a fast-growing and highly adaptable plant species, has recently gained increasing attention as a potential phytoremediation agent due to its capacity to accumulate and interact with environmental pollutants. The aim of this study is to explore the use of Fourier Transform Infrared (FTIR) combined with chemometric approaches to characterize hemp plants exposed to different PFAS. To this end, C. sativa was grown in hydroponic solutions in the absence or presence of PFAS (perfluorooctanoic acid: PFOA or perfluorooctane sulfonate: PFOS) at a concentration of 1 mg L⁻¹ for 15 days. FTIR spectroscopy was then employed to evaluate the variations in spectral response of C. sativa plants resulting from PFAS contamination. To enhance the interpretability of the acquired spectra and minimize the effects of noise and baseline fluctuations, a chemometric approach was applied, primarily based on preprocessing techniques and Principal Component Analysis (PCA). This strategy allowed the identification of spectral changes associated with PFAS uptake and facilitated a clearer distinction between exposed and unexposed plant tissues. Overall, this integrated FTIR–chemometric approach represents a preliminary step toward the development of reliable strategies for investigating PFAS–plant interactions both at laboratory and field scales. The outcomes lay the groundwork for future implementation of spectroscopic tools in phytoremediation studies and contribute to the design of monitoring frameworks aimed at assessing and optimizing PFAS removal efficiency in real environmental conditions.