采用液相色谱-串联质谱法测定复合塑料食品包装袋中的二氨基甲苯的含量。将食品包装袋用水洗干净后,按照2 mL·cm-2的比例装入4%(体积分数)乙酸溶液,密封后在一定温度下恒温一定时间后,将浸泡液用氨水(1+9)溶液调节至弱碱后,以SB-C18色谱柱为分离柱,以10 mmol·L-1乙酸铵-甲醇(98+2)混合液为流动相进行洗脱。质谱中选择电喷雾正离子源和多反应监测模式。二氨基甲苯的4种同分异构体的质量浓度在一定范围内与峰面积呈线性关系,检出限(3S/N)在0.012~0.027 μg·L-1之间。加标回收率在88.0%~108%之间,测定值的相对标准偏差(n=6)在2.2%~3.2%之间。

LC-MS/MS was applied for the determination of diaminotoluene in composite plastic bags for food packaging. The plastic bags were washed with water and then were filled with 4% (φ) acetic acid solution in a ratio of 2 mL·cm-2. The bags were sealed and heated at a definite temperature for definite time. Then 10% (φ) ammonia solution was added into the soaking solution to make a weak alkaline solution. The obtained solution was separated on a SB-C18 chromatographic column with a mixture of 10 mmol·L-1 ammonium acetate solution and methanol (98+2) as mobile phase. ESI+ and MRM were adopted in MS. Linear relationships were found between the peak areas and the mass concentrations of the 4 isomers of diaminotoluene in definite ranges, with detection limits (3S/N) in the range of 0.012-0.027 μg·L-1. Recovery rates obtained by standard addition method were in the range of 88.0%-108%, and RSDs (n=6) were in the range of 2.2%-3.2%.