气相色谱-串联质谱法测定塑料儿童玩具中15种N-亚硝胺残留量

Determination of 15 Kinds of N-nitrosamines Residues in Plastic Children’s Toys by GC-MS/MS

基于溶解沉淀-气相色谱-串联质谱(GC-MS/MS)建立了ABS和PVC塑料玩具中15种N-亚硝胺残留量的测定方法。塑料玩具样品经相应溶剂溶解、甲醇沉淀后,在4℃下,以13 000 r/min离心5 min,取上层清液,过0.22μm滤膜后上机检测。通过DB-17MS色谱柱分离,串联质谱多反应监测模式(SRM)测定,外标法定量。自制阳性样品的回收率测定结果表明,溶解沉淀法具有较高的提取率。GC-MS/MS具有较强的选择性,样品中的杂质峰未对N-亚硝胺的检测产生干扰。由于存在溶剂效应和基质效应,需要采用空白基质匹配的标准曲线进行定量分析。该方法对于不同物质的定量限(LOQ)为0.02~0.2 mg/kg,在线性范围0.02~20 mg/kg内的相关系数(R^2)不小于0.996 3。ABS和PVC样品的回收率分别在77.6%~126.2%和75.6%~122.4%之间,相对标准偏差(RSD,n=6)分别在1.7%~8.7%和1.4%~10.2%之间。将该方法应用于市售的35个ABS玩具和30个PVC玩具实际样品检测,结果未检出N-亚硝胺。该方法简便快速、准确灵敏,适用于两类塑料玩具中15种N-亚硝胺残留量的检测。

A method for the determination of 15 N-nitrosamines residues in ABS and PVC plastic toys was developed based on dissolution precipitation-gas chromatography-tandem mass spectrometry(GC-MS/MS).After dissolving in the corresponding solvent and precipitating with methanol,the plastic toy samples were centrifuged at 13000 r/min for 5 min at 4℃.The supernatant was collected and then detected by instrument after filtered through 0.22μm membrane.The analytes were separated by DB-17MS column,scanned by multiple reaction monitoring(SRM),and quantified by external standard method.The results of recovery of self-made positive samples showed that the dissolution precipitation method had a high extraction rate.GC-MS/MS had strong selectivity,impurity peaks in samples did not interfere with the detection of N-nitrosamines.Due to the solvent effect and matrix effect,the standard curve matched with blank sample matrix was needed for quantitative analysis.The limits of quantification(LOQs)for different substances were 0.02-0.2 mg/kg,and the linear ranges were 0.02-20 mg/kg with the correlation coefficient(R^2)greater than 0.9963.The recoveries of N-nitrosamines in ABS and PVC samples ranged from 77.6%to 126.2%and 75.6%to 122.4%,respectively.The relative standard deviation(RSD,n=6)ranged from 1.7% to 8.7%and 1.4%to 10.2%,respectively.Finally,the method was applied to the actual samples of 35 ABS toys and 30 PVC toys sold in the market,and no N-nitrosamines were detected.The method is simple,rapid,accurate and sensitive.It is suitable for the determination of 15 N-nitrosamines residues in two kinds of plastic toys.