顶空-气相色谱法测定聚丙烯腈类食品接触材料中3种腈类化合物残留量

Determination of Residues of Three Nitrile Compounds in Polyacrylonitrile Food Contact Materials by Headspace-Gas Chromatography

建立了顶空-气相色谱法测定聚丙烯腈类食品接触材料中3种腈类化合物残留量的分析方法。通过优化前处理溶剂种类、溶剂体积、样品前处理溶解时间,以及平衡温度和时间等色谱条件,实现了对3种腈类化合物残留量的常规、快速分析。结果表明:3种腈类化合物在完全分离的前处理和色谱条件下,在0.02～2.0 mg/L质量浓度范围内线性关系良好,线性相关系数均大于0.999;3种腈类化合物的方法定量限(10S/N)为0.045～0.052 mg/kg,低、中、高质量分数的回收率为89.4%～110.7%,相对标准偏差(RSD)为3.5%～9.8%;方法满足了聚丙烯腈类食品接触产品中3种腈类化合物残留量的检测要求。实际检测中发现丙烯腈-丁二烯-苯乙烯共聚物(ABS)和丙烯腈-苯乙烯共聚物(AS)材质除含有较高的丙烯腈外,还含有一定量的丙腈和乙腈单体,因此需要关注AS和ABS材质等食品接触材料产品中存在腈类化合物的风险。

A headspace-gas chromatography method was developed for the determination of residual amounts of three nitrile compounds in polyacrylonitrile food contact materials.By optimizing the pretreatment conditions such as the type of solvent,the volume of solvent,the dissolution time of the sample,and the chromatographic conditions such as equilibrium temperature and time,the conventional and rapid analysis of the residual amount of three nitrile compounds was realized.The results showed that the three nitrile compounds could be separated completely under the pretreatment and chromatographic conditions,the linear relationship was good in the concentration range of 0.02-2.0 mg/L,and the linear correlation coefficient was greater than 0.999.The detection limit with 10S/N was 0.045-0.052 mg/kg,the recovery rate of low,medium and high content was 89.4%-110.7%,and the relative standard deviation(RSD)was 3.5%-9.8%.The detection requirements of residual amounts of three nitrile compounds in the food contact products of polyacrylonitrile were satisfied.In the actual test,it was found that acrylonitrile-butadiene-styrene(ABS)and acrylonitrile-styrene(AS)materials not only contained more acrylonitrile,but also contained certain acrylonitrile and acetonitrile monomers.Therefore,it is necessary to pay attention to the risk of nitrile compounds in food contact materials such as AS and ABS.