Migration of Diethyl-Hexyl-Phthalate from Plastic Containers and Oak Casks to Tequila During Long-Term Storage and...

Tequila is frequently stored or aged in polymer containers and oak casks, which can enable the migration of phthalates such as di-(2-ethylhexyl) phthalate (DEHP), an endocrine-disrupting chemical. We quantified DEHP in tequila (55% ethanol) stored in LDPE tanks, HDPE jerry cans, PET carboys, and French oak casks with and without thermal treatment during long-term storage/aging (up to 18 and 11 months, respectively). Monthly samples were extracted and analyzed by GC-MS. Migration kinetics were evaluated using empirical exponential/sigmoidal models and an analytical solution of Fick's second law for a semi-infinite slab. In plastics, DEHP increased nonlinearly and was best described by a modified Gompertz model, exhibiting a lag phase up to 42 days (~month 2), maximum transfer rates (Rmax) up to 0.82 µg L^-1 day^-1, and late-time concentrations near 120 µg L^-1. The non-toasted oak cask previously used for wine showed exponential behavior, reaching ~185 µg L^-1 and fitting the Minchev-Minkov model, whereas the toasted cask showed minimal transfer. Although concentrations remained below a reference safety limit (1500 µg kg^-1), the results indicate that food-contact plastics and commonly used oak casks are not risk-free under prolonged contact, supporting model-based forecasting for quality control.