Determination of Migrations of 23 Primary Aromatic Amines in Polyamide Kitchenware by Ultra-High Performance Liquid Chromatography-Tadem Mass Spectrometry

The sample with surface area of 0.6 dm² of polyamide kitchenware was immersed in 100 mL of 3% (mass fraction) acetic acid solution, and the mixture was heated at (100±3)℃ for 2 h. After the immersing process was repeated twice, each immersing solution was collected, and an aliquot (1 mL) was filtered with a 0.22 μm needle filter membrane. The filtrate was used for determination under optimized instrument working conditions. CORTECS T3 column (100 mm×2.1 mm, 2.7 μm) was used as the stationary phase, and methanol containing 0.1% (volume fraction) formic acid-water mixed solution at various volume ratios was used as the mobile phase for gradient elution. The primary aromatic amines (PAAs) separated were detected by MS/MS with an electrospray ion source in positive mode under multiple reaction monitoring mode. As shown by results that the mass concentrations of 23 PAAs were all linearly related with their corresponding peak areas in the range of 1-20 μg·L^-1, with detection limits (3S/N) in the range of 0.04-0.5 μg·L^-1. Test for recovery was made on the negative samples by standard addition method, giving values of recovery in the range of 90.9%-107%, and RSDs (n=6) of the determined values ranged from 0.40% to 7.3%. The proposed method was applied to the analysis of 10 kinds of polyamide kitchenware, and 4,4'-MDA, 4-CoT and 4-CA were detected in the 4 types of kitchenware, including flat spatula, rice spoon, potato pressure and soup spoon, and the detection amounts (0.4-1.3 μg·kg^-1) decreased with the increase of immersing times.