Diffusion coefficient of antimony leaching from polyethylene terephthalate bottles into beverages

A variety of polyethylene terephthalate (PET) bottles commercially available as soft drink containers from 80 different brands was collected in Japan and subsequently examined to determine the amount of Sb in both the PET plastic and drink. The concentration of Sb in the plastic material ranged from 0.1 to 216.5 mg/kg, while this value ranged from 0.3 to 1.6 μg/L in bottled solutions. The diffusion coefficients of Sb in PET samples were determined at 25, 40, 55, and 70 °C. The migrated-Sb in all simulated food solutions (e.g., ultra pure water, 4% acetic acid, and 50% ethanol) increased with storage time and temperature. The temperature-dependent diffusion coefficients were derived from the Arrhenius equation. The predicted model for Sb migration suggested that storage conditions of all PET drink products should be below 70 °C for a maximum of 72 d to avoid Sb levels above the recommended value of 5 μg/L, which is based on the European standards.

► Sb concentration in all samples was below the Japanese standards for drinking water.
► The diffusion coefficients of Sb in PET were determined ranging from 25 to 70 °C.
► Temperature-dependent prediction model for Sb migration was derived.
► The model suggested storage conditions for PET drinks below 70 °C of 72 d.