Evaluation of plasticizer release from food contact tinplate coatings across various extraction and simulation conditions

Migration of 20 Phthalate Esters from food-contact tinplate coatings was quantified using a validated gas chromatography–mass spectrometry (GC–MS) method. Among seven tested solvents, Tetrahydrofuran (THF) exhibited the highest extraction efficiency across concentration levels. Migration tests using water, 20% ethanol, and n-heptane as food simulants at 4 °C and 60 °C for 15min, revealed temperature-dependent increases. As a representative example, Di-isobutyl phthalate in n-heptane increased from 0.912 ± 0.103 to 1.116 ± 0.013 mg/kg. At the high spiking level, Dibutyl Phthalate migration reached 10.9 ± 0.280 mg/kg. THF consistently outperformed n-Heptane in the extraction-efficiency screening, particularly at low and medium concentrations. Analysis of 6 commercial canned foods detected Diethyl phthalate and Di-2-Ethyl hexyl phthalate up to 51.0 ± 4.43 and 8.67 ± 0.72 mg/kg, respectively. These results confirmed that tinplate coatings can release plasticizers and demonstrated that THF is a reliable extraction solvent for coating characterization and method development in food-contact safety assessment.