Determination of Amounts of Methacrylates and Methacrylic Acid of Food-Containing Polymethacrylate Material Migrated Into Food Simulants by HPLC

Aqueous solutions (50.0 mL each) of 4% acetic acid and 10%, 20%, 50%, 95% ethanol were used separately as food simulants (abbrev. as FSs), and thin pieces of PMA plastic (with testing area of 0.3 dm²) were taken as the specimen to be soaked in the 5 FSs in the testing under 3 soaking conditions:1 70℃ for 2 h; 2 40℃ for 10 d and 3 60℃ for 2 h (95% ethanol solution). After soaking, the solution was filtered through 0.45 μm filtering membrane, and the filtrate was used for HPLC analysis under the working condition of the instrument. Shim Sen-VD C₃₀(250 mm×4.6 mm, 3 μm) chromatographic column with column temperature at 35℃, and mixtures of (A) 0.1% (volume fraction) H₃PO₄ acid solution and (B) methanol in various ratios were selected for HPLC separation by gradient elution with flow-rate of 0.5 mL·min^-1. 13 compounds of the methacrylates and methacrylic acid were well-separated and determined by UV-detector at the wavelength of 210 nm. As shown by the results, linearity ranges of the standard curves of the 13 compounds were found same between 1 to 20 mg·L^-1. Detection limits (3S/N) found were in the range of 0.015 to 0.084 mg·L^-1. Tests for recovery were made by standard addition method in 5 FS, and 3 soaking conditions separately, and as shown by the results, values of average recovery for the 13 compounds were all over 85%, and RSDs (n=6) all less than 6%.