顶空/气相色谱-质谱法分析方便面印刷包装材料中挥发性有机物

摘要

利用顶空/气相色谱-质谱(HS/GC-MS)联用法对袋装方便面印刷包装材料中7种挥发性有机物(异丙醇、乙酸乙酯、苯、乙酸丁酯、乙苯、间/对二甲苯、邻二甲苯)进行了检测分析.优化的实验参数为:平衡温度80℃,平衡时间40 min.本方法线性关系良好,7种挥发性有机物的相关系数均大于0.9991,检出限为0.004～0.007 mg/m2；回收率为93％～102％;相对标准偏差≤3.1％.结果表明:未印刷的塑料薄膜中包含异丙醇、乙酸乙酯、乙酸丁酯；印刷后的塑料薄膜中包含这7种物质,其中异丙醇、乙酸乙酯、乙酸丁酯的含量增大；复合塑料膜中异丙醇、乙酸乙酯、乙酸丁酯、间/对二甲苯、邻二甲苯的含量增大,苯和乙苯的含量减小,VOCs总量为0.42 mg/m2,苯类溶剂残留量为0.25 mg/m2.黑色油墨中VOCs含量较高；其次是黄色和品红色油墨；白色油墨中VOCs的含量较低；粘合剂中包含有异丙醇、乙酸乙酯、乙酸丁酯、间/对二甲苯、邻二甲苯.降低印刷油墨和粘合剂中苯类溶剂的含量是保证方便面包装材料安全性的重要途径；延长印后干燥时间、升高干燥温度,方便面塑料包装袋中挥发性有机物的残留量有所降低.%A headspace gas chromatography/mass spectrometric (HS/GC-MS) method was used to analyze seven volatile organic compounds (VOCs) including isopropyl alcohol, ethyl acetate, benzene, butyl acetate, ethyl benzene, m/p-Xylene, o-Xylene in printing and packaging materials of instant noodles. The important experiment parameters related to the HS/GC-MS method were optimized, equilibrium temperature of 80 °C and headspace equilibrium time of 40 min. In the experiment, linear calibration curves of the seven VOCs were obtained with correlation coefficients of more than 0. 9991, the detection limits were in the range of 0. 004-0. 007 mg/m2, the recoveries ranged from 93% to 102% with RSD less than 3. 1%. The results indicated unprinted plastic film contained isopropyl alcohol, ethyl acetate, butyl acetate, printed plastic film contained the seven VOCs, and the contents of the three VOCs including isopropyl alcohol, ethyl acetate and butyl acetate were higher than unprinted plastic film. Plastic laminated films contained the seven VOCs, the contents of the five VOCs including isopropyl alcohol, ethyl acetate, butyl acetate, m/p-Xylene, o-Xylene were higher than printed plastic film, and the contents of benzene and ethylbenzene were lower. The amount of the seven VOCs in the plastic laminated films was 0. 42 mg/m2, and the benzene solvent content was 0. 25 mg/m2. The content of VOCs in black ink was higher, followed by yellow ink and magenta ink, while white ink had the lower content. Binder contained isopropyl alcohol, ethyl acetate, butyl acetate, m/p-Xylene, o-Xylene. Reducing benzene solvent contents in printing inks and binder was an important procedure to ensure the safety of the packaging materials of instant noodles. Longer drying time and higher drying temperature could help reduce the residual quantity of VOCs in packages of instant noodles.