搅拌子固相吸附-热脱附-气相色谱/质谱/质谱法快速测定空气中多环芳烃

Determination of Polycyclic Aromatic Hydrocarbons in Air by Stir Bar Sorptive Extraction-Thermal Desorption-Gas Chromatography Tandem Mass Spectrometry

利用聚二甲基硅氧烷（PDMS）涂层的搅拌子作为大气被动采样器，建立了搅拌子同相吸附一热脱附一气相色谱／质谱顺谱联用法（SBSETD—GC／MS／MS）快速测定室内空气中多环芳烃的方法。在搅拌子表面涂渍标准样品，待溶剂挥发后放于脱附管内，在多反应监测模式（MRM）下，对多环芳烃子离子、碰撞能量、热脱附参数（脱附温度300℃，冷阱捕集温度-60℃和脱附时间6min）等条件进行了优化，并建立标准曲线；以12种氘代同位素PAHs为内标，建立了多窗口下16种美同环保署优先检测多环芳烃的分析方法，方法回收率在45．1％～109％之间，检出限为0．0200．054ng。利用本方法对模拟燃煤前后室内大气中悬挂搅拌子中的多环芳烃进行了被动吸附与检测，燃煤前后室内大气样品中16种多环芳烃含量分别为4．24～5．32ng和172～200ng。

A method was developed for the determination of polycyelic aromatic hydrocarbons （PAHs） in indoor air by a novel passive air sampler, polydimethylsiloxane （PDMS）-coated stir bar sorptive extraetion （SBSE）, which is detected by thermal desorption （TD） coupled to gas chromatography/triple quadrupole mass spectrometry （GC/MS/MS）. PAH standard was added to the surface of stir bar, and it would not be put into a desorption tube until solvent was evaporated. The experimental conditions of daughter ions, collision energy under multiple reactions monitoring （MRM） mode were optimized. To enhance detection sensitivity, TD parameters like desorption temperature （300℃）, cooled injection system （CIS） temperature （-60℃） and desorption time （6 min） were also optimized. 12 deuterated internal standards were applied to identify and quantify 16 EPA-PAH congeners under 4 functions. The method recovery is 45. 1%- 109% and the limits of detection （LOD） were in the range of 0. 020-0. 054 ng. The established method is further applied to analyze 16 PAHs of indoor air before and after coal combustion by hanging stir bars in a room as passive air sampler. The PAHs concentrations of indoor air before and after coal combustion samples were 4.24-5.32 ng and 172-200 ng, respectively