食品包装用聚苯乙烯树脂中苯乙烯和乙苯单体的测定方法

Determination of styrene and ethylbenzene monomers in food packaging polystyrene

探讨了测定食品包装用聚苯乙烯树脂中苯乙烯和乙苯单体的粉碎-溶解-气相色谱法。采用液氮冷冻粉碎仪粉碎样品,用25mL体积分数为4︰1的N,N-二甲基甲酰胺(DMF)和二甲基乙酰胺(DMA)混合溶液溶解,选用安捷伦19091S-433毛细管柱作为分离色谱柱。结果表明,经过液氮冷冻粉碎样品能使苯乙烯和乙苯单体的提取效果大大提高。该方法中,苯乙烯单体的检出限为0.002%,乙苯单体的检出限为0.001%。苯乙烯单体的加标回收率为85%～105%,相对标准偏差(RSD)<10%;乙苯单体的加标回收率为92%～110%,相对标准偏差(RSD)<9%。

A smash-dissolution-gas chromatographic method is discussed for the determination of styrene and ethylbenzene monomers in polystyrene used for food packaging. Samples were smashed by liquid nitrogen frozen grinding device, and dessolved in 25mL DMF and DMA mixed solution （4：1, V/V ）. An Agilent 19091S-433 capillary column was used for separation. It was showed that the extraction efficiency for sty-rene and ethylbenzene monomers was enhanced greatly by liquid nitrogen frozen smash method. The detection limits were 0. 002% and 0. 001% and the recoveries were 85-105% （RSD〈10%） and 92-110% （RSD%） for styrene monomer and ethylbenzene monomer, respectively.