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

A method was developed for the determination of polycyclic aromatic hydrocarbons (PAHs) in indoor air by a novel passive air sampler, polydimethylsiloxane (PDMS)-coated stir bar sorptive extraction (SBSE), which is detected by thermal desorption (TD) coupled with gas chromatography/triple quadrupole mass spectrometry (GC/MS/MS). A PAH standard was added to the surface of the stir bar, and it was not put into a desorption tube until solvent was evaporated. Daughter ions, collision energy under multiple reactions monitoring (MRM) mode are optimized. To enhance the detection sensitivity, TD parameters such as desorption temperature (300 °C), cooled injection system (CIS) temperature (−60 °C) and desorption time (6 min), were also optimized. Twelve deuterated internal standards were applied to identify and quantify 16 EPA-PAH congeners under 4 functions. The method recovery was 45.1%–109.0% and the limits of detection (LOD) were in the range 0.020–0.054 ng/sample. The established method was 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 PAH concentrations of indoor air before and after coal combustion samples were 4.24–5.32 ng/sample and 172–200 ng/sample, respectively.