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

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0.22 μm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（R²）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。

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

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 13 000 r/min for 5 min at 4 ℃. The supernatant was collected and then detected by instrument after filtered through 0.22 μm 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 ofN-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 (R²) greater than 0.996 3. The recoveries ofN-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 noN-nitrosamines were detected. The method is simple, rapid, accurate and sensitive. It is suitable for the determination of 15N-nitrosamines residues in two kinds of plastic toys.