Tracing the Fate of PFAS in Black Soldier Fly Larvae-Based Food Waste Valorisation Systems Using High-Resolution Mass Spectrometry

Black Soldier Fly Larvae (Hermetia illucens, BSFL) bioconversion offers a sustainable approach to food waste management, yet the fate of environmental contaminants such as per- and polyfluoroalkyl substances (PFAS) within these systems remains poorly understood. In this study, BSFL were reared on five distinct food waste streams differing in composition and anticipated levels of contamination: (B) bread and vegetable mix and (S) soybean waste were prepared in the lab to represent homogeneous food waste and three food wastes from different facilities: (CC) childcare facility waste, (WB) mixed waste block, and (WL) supermarket waste represented heterogenous post-consumer food wastes. Samples of each substrate, 5th instar larvae, and frass were collected for PFAS analysis.

Untargeted screening was performed using high-performance liquid chromatography coupled with Orbitrap high-resolution mass spectrometry (HPLC-HRMS). Subsequent data processing with Fluoromatch facilitated qualitative identification and confidence assessment of PFAS species across matrices. Chemometric analysis was employed to examine shifts in chemical profiles between feed, larvae, and frass, providing insight into contaminant transfer, potential transformation, and accumulation dynamics.

Preliminary results suggest differential PFAS profiles between waste streams, reflecting both feedstock composition and contamination potential. The study contributes to understanding contaminant pathways in BSFL-based circular systems and highlights the analytical challenges associated with PFAS identification in complex biological and waste matrices. Findings will inform risk assessment and the development of safe, sustainable waste valorisation practices.