Rapid Determination of Specific Migration Amount of 2,2,4-Trimethyl-1,3-Pentanediol Diisobutyrate in Plastics for Food Contact by GC-MS

GC-MS was applied to the rapid determination of amount of 2,2,4-trimethyl-1,3-pentanediol diisobutyrate migrated from plastics for food contact into 6 food simulant, i.e.water, 4% (volume fraction, the same below) acetic acid solution, 20% (volume fraction, the same below) ethanol solution, 50% ethanol solution, isooctane and olive oil. The DB-5MS chromatographic column (30 m×0.25 mm, 0.25 μm) was used for GC separation and the selected ion monitoring mode was adopted in MS determination. When food simulants were water, 4% acetic acid solution, 20% ethanol solution and 50% ethanol solution, extraction solvent was n-hexane, extraction repeat was 1 and extraction time was 10 min; when food simulant was isooctane, no extraction was required; when food simulant was olive oil, extraction solvent was methanol, extraction repeat was 3 and extraction time was 10 min. Linear relationship between values of peak area and mass concentration of TXIB was kept in the range of 0.03-1.00 mg·L^-1 (0.10-2.00 mg·kg^-1 when food simulant was olive oil), with detection limit (3S/N) of 0.01 mg·kg^-1 (0.03 mg·kg^-1 when food simulant was olive oil) and lower limit of determination (10S/N) of 0.03 mg·kg^-1 (0.10 mg·kg^-1 when food simulant was olive oil). On the base of blank food simulants, test for recovery was made by standard addition method; values of recovery found were in the range of 82.7%-110%, with RSDs (n=6) of determined values in the range of 2.3%-10%.