固相萃取-气相色谱-串联质谱法测定乳胶儿童用品中15种N-亚硝胺及其前体物的迁移量

Determination of migration of 15 N-nitrosamines and N-nitrosatable substances from children ' s latex articles by gas chromatography-tandem mass spectrometry using solid phase extraction

建立了同时测定乳胶儿童用品中15种Ⅳ．亚硝胺及其前体物迁移量的固相萃取-气相色谱-串联质谱（SPE-GC—MS／MS）分析方法。以人工唾液作为迁移模拟物，以ChromabondEasy固相萃取柱（填料的主要成分是极性修饰的聚乙烯-二乙烯基苯共聚物）对迁移液中的N-亚硝胺分析物进行净化，采用HP一5MSUI色谱柱分离，MS／MS在多反应监测模式下进行定性及定量分析。15种N-亚硝胺在5～2000μg／L范围内呈良好的线性关系，相关系数均大于0．998；方法定量限（S／N：10）为0．625-12．50μg/kg，低于欧盟2009／48／EC指令的限量要求。在低、中、高3个添加水平的回收率为53．8％-116．2％、52．7％～105．1％和49．5％～102．9％；日内精密度分别为1．3％-14.0％（n=6），目间精密度为1．6％-7．6％（n=4）。采用本方法对婴儿奶嘴样品和气球样品进行了测定，其中4件奶嘴和7件气球样品中检出亚硝胺及其前体物，奶嘴和气球中N-亚硝胺的总检出含量分别为0．0499～0．126mg／kg和0．515～41．2mg／kg；N-亚硝胺前体物总检出量分别为0．0264～0．0300mg／kg和0．187～12．5mg／kg。

A method based on gas chromatography-tandem mass spectrometry （GC-MS/MS） using solid phase extraction （SPE） has been developed for the determination of 15 N-nitrosa- mines from children＇ s latex articles. Artificial saliva was used as the migration solution to extract N-nitrosamines in children＇s latex articles. And then a polar modified polystyrene- divinylbenzene copolymer （Chromabond Easy） was used for the selective SPE of the analytes in the migration solution. The analytes were then separated on an HP-SMS UI GC column and determined by MS/MS in multiple reaction monitoring mode for qualitative and quantitative analysis. Good linearity ranged from 5μg/L to 2 000μg/L was observed for all the compounds （R2 〉 0. 998 ） and the limits of quantification for the 15 N-nitrosamines were 0. 625 - 12.50μg/kg （S/N = 10）, which were lower than the limits required by the EU 2009/48/EC Directive. The average recoveries of the target analytes at low, medium, and high spiked levels were in the ranges of 53.8% - 116.2%, 52.7% - 105. 1% and 49.5% - 102. 9%, respectively. The average within-day and between-day RSDs were from 1.3% to 14.0% （ n = 6 ） and from 1. 6% to 7.6%（n = 4）, respectively. The proposed method was used to monitor N-nitrosamines in baby nip- ples and balloons, and N-nitrosamines were found in some samples. The total contents of the 15 N-nitrosamines in the analyzed nipples and balloons samples ranged from 0. 049 9 mg/kg to 41.2 mg/kg. And the total contents of the N-nitrosatable substances in the analyzed samples ranged from 0. 026 4 mg/kg to 12.5 mg/kg.