Determination of 24 Free Primary Aromatic Amines in Tattoo by Gas Chromatography-Mass Spectrometry with Sampling by Water Infiltration

After wetting with water and peeling the water-transfer sticker of the tattoo sample, the ink on the film was removed with a glass rod, and heated to constant weight in an oven at 80 ℃. An aliquot (1.0 g) of the sample was taken, and 10 mL of ethyl acetate was added. The mixture was extracted by ultrasound at 35 ℃ for 60 min, and the extract was introduced into gas chromatography-mass spectrometer. Twenty-four free primary aromatic amines were separated by programmed temperature on the DB-35MS capillary column, and detected by the mass spectrometer equipped with electron impact ion source. It was shown that the mass concentrations of each free primary aromatic amine were linearly related with the peak areas in the same range of 2.5-30 mg·L^-1, with detection limits (3S/N) in the range of 0.8-2.6 mg·kg^-1. Test for recovery was made by standard addition method, giving results of recovery in the range of 94.8%-99.8%, and RSDs (n=7) of the determined values ranged from 0.60% to 2.6%. The proposed method was applied to the analysis of the 7 actual tattoo samples, and 2,4-dimethylaniline was detected in all samples, with detection amounts in the range of 1.32-3.94 mg·kg^-1.