Abstract: A method for the determination of 2,4-diaminotoluene in Mianpi composite packaging film bags was established based on ion-exchange solid-phase extraction-gas chromatography-mass spectrometry (GC-MS). The samples were immersed in 4% (v/v) acetic acid solution. 2,4-Diaminotoluene was enriched from a 50.0 mL soak solution with an activated and balanced MCX solid-phase extraction column. The MCX column was washed with 5.0 mL water and eluted with 3.0 mL ammoniated methanol. 2,4-Diaminotoluene was detected quantitatively by GC-MS after derivatization with heptafluorobutyric acid anhydride. In the mass concentration range of 1-50 μg/L, the linear correlation coefficient (r) was 0.9991. The limit of detection (LOD, S/N=3) was 0.2 μg/L, and the limit of quantification (LOQ, S/N=10) was 0.6 μg/L. The recovery of 2,4-diaminotoluene was in the range of 89.0%-94.2%. The relative standard deviations (RSDs) were 1.9%-3.6%. This method requires neither pH adjustment of the soak solution in the pre-processing step nor liquid-liquid extraction. With this method, the pre-processing step is greatly simplified and there is minimal consumption of organic solvents. Further, the method is simple, convenient, and accurate, and it is suitable for the determination of 2,4-diaminotoluene in Mianpi composite packaging film bags.

Key words: ion exchange solid phase extraction, gas chromatography-mass spectrometry (GC-MS), 2,4-diaminotoluene, Mianpi composite packaging film bag