Analytical Determination of Selected Volatile Fumigants and Sterilants in Food: Current Status and Future Perspectives

Volatile fumigants and sterilants remain relevant to the protection of stored commodities and international food trade, yet their residue analysis presents challenges that differ substantially from those encountered for conventional pesticide residues. Their high volatility, chemical reactivity and diverse residue formation pathways complicate sampling, sample preparation, instrumental determination and regulatory interpretation. This review examines compound-specific analytical strategies for ethylene oxide, phosphine, methyl bromide and sulfuryl fluoride. These four representative compounds illustrate distinct residue behaviours involving parent compounds, transformation products, residues derived from fumigant-generating precursors and inorganic marker ions. The discussion focuses on gas chromatography-based methodologies for volatile analytical targets and associated transformation products, alongside complementary analytical approaches, including liquid and ion chromatography for inorganic marker ions. Sampling and sample-preparation challenges, headspace-based methodologies, marker residue determination, method validation and regulatory performance requirements are considered in relation to food safety monitoring. Particular attention is given to the relationship between analytical targets and residue definitions and to the limitations associated with interpreting inorganic marker residues as evidence of fumigant use. Priorities for further development include harmonised validation and sample-handling procedures, improved occurrence and storage-stability data, and fit-for-purpose analytical methods capable of supporting reliable regulatory monitoring.