基于硅酸镁前处理富集的气相色谱-串联质谱分析方法检测空气中9种挥发性N-亚硝胺

Determination of Nine Volatile Nitrosamines in Air by Magnesium Silicate as Adsorbent in Combination with Gas Chromatography-Tandem Mass Spectrometry

针对空气中N-亚硝胺检测困难、成本高的问题,通过硅酸钠对廉价的无定形二氧化硅进行刻蚀,与硫酸镁反应得到硅酸镁负载填料,将其装入柱管制得N-亚硝胺捕集器,与气相色谱-串联质谱(GC-MS/MS)联用建立了一种检测空气中9种挥发性N-亚硝胺的分析方法。本方法前处理步骤简单,富集后的洗脱液即可进入仪器分析。对影响方法回收率的色谱柱类型、升温程序、定性定量离子对和洗脱溶剂等参数进行了优化。在最佳实验条件下,9种挥发性N-亚硝胺的线性范围为50~5 000 ng/m^(3),最低检出限为11 ng/m^(3)。在实际空气样品检测中,9种挥发性N-亚硝胺回收率为96.8%~105.6%,RSD为3.8%~8.8%。这表明,以该易制备、低成本的硅酸镁负载填料填充的小柱,能替代价格昂贵的商品化亚硝胺捕集器(94.7%~103.2%),且与普适性更强的GC-MS/MS联用建立的检测方法,能够应用于空气中9种挥发性亚硝胺的检测。

The amorphous silica was etched by sodium silicate and reacted with magnesium sulfate to obtain magnesium silicate-loaded packing,which was loaded into a column to obtain a nitrosamine trap.An analytical method for the determination of nine volatile N-nitrosamines in air was established by coupling with GC-MS/MS.The pretreatment steps of the method are simple,and the enriched eluate can be directly analyzed by the instrument.The parameters,such as column type,warming procedure,qualitative and quantitative ion pair and elution solvent,were optimized.Under the optimal experimental conditions,the linear ranges of the nine volatile N-nitrosamines were 50-5000 ng/m 3,and the detection limit was 11 ng/m 3,respectively.The recoveries of the nine volatile N-nitrosamines were 96.8%-105.6%with the relative standard deviations(RSDs)of 3.8%-8.8%in the real air samples.This indicates that the column filled with this easy-to-prepare and low-cost magnesium silicate-loaded packing material can replace the expensive commercial nitrosamine trap(94.7%-103.2%),and the method established in conjunction with the generalized GC-MS/MS can be applied to the determination of the nine volatile nitrosamines in air.