Determination of Migrations of 5 Acrylic Compounds in Food Contact Materials by Ultra-High Performance Liquid Chromatography and Discussion of Their Migration Rules

A method for determination of migrations of 5 acrylic compounds in food contact materials, including acrylic acid, methyl acrylate, 2-hydroxyethyl acrylate, methacrylic acid, and 2-hydroxyethyl-2-methyl-2-acrylate, was proposed by ultra-high performance liquid chromatography. Migration tests were conducted using water, 20% (volume fraction, the same below) ethanol solution, 4% (volume fraction), acetic acid solution, and olive oil as food simulants in accordance with the provisions of GB 31604.1—2015 and GB 5009.156—2016. Direct injection analysis was made on the soaking solution of water-based simulants, which passed through a 0.22 μm organic filter membrane. 5 g of olive oil soaking solution was taken, and placed in a 50 mL-centrifuge tube, and 5 mL of methanol was added. The mixed solution was vortexed for 2 min, centrifuged at a rotational speed of 8 000 r·min⁻¹ for 5 min, and passed through a 0.22 μm organic filter membrane. The filtrate was analyzed by the instrument. Xbridge BEH C₁₈ chromatographic column was used as the stationary phase and the mixed solution composed of 0.1% (volume fraction) phosphoric acid solution and acetonitrile at different volume ratios was used as mobile phase for gradient elution. The solution was determined at 210 nm by a photodiode array detector. As shown by the results, linear relationships between the corresponding peak areas and mass concentrations of acrylic compounds in the water-based simulants were kept in the range of 0.3-10.0 mg·L⁻¹, with detection limits (3S/N) of 0.1 mg·L⁻¹. Linear relationships between the corresponding peak areas and mass fractions of acrylic compounds in the olive oil were kept in the range of 0.3-10.0 mg·kg⁻¹, with detection limits (3S/N) of 0.1 mg·kg⁻¹. Test for recovery was made by the standard addition method, giving results in the range of 80.6%-99.8%, with RSDs (n=6) of the determined values less than 8.0%. This method was used for the analysis of food contact material samples, and methyl acrylate was detected in one of the samples. The migration rules of methyl acrylate in positive food contact materials were investigated under different simulants, different migration temperatures and different migration time. As shown by the results, acrylic compounds had strong migration ability in 20% ethanol solution and olive oil, and the migrations increased with the increase of migration temperature. The growth rate of migration was tended to stabilize after reached the maximum, and the migration time of the maximum migration was shortened with the increase of temperature.