Application of gas chromatography coupled with tandem mass spectrometry for the assessment of PAH levels in non industrial indoor air

A gas chromatographic coupled to a triple quadrupole tandem mass spectrometric (GC-MS/MS) method was optimized in order to measure the levels of polycyclic aromatic hydrocarbons (PAHs) in different non industrial indoor environments using active (filter + XAD-2) and passive (polyurethane, PUF) samplers. Ultrasonic and soxhlet extractions were used for active and passive samplers, respectively. The precision and accuracy of the analytical methods used were tested by spiking PUF, filters and XAD-2 with different working standards containing all analyzed PAH compounds. The proposed methods were applied to the analysis of real samples collected in the urban area of Ciudad Real, Spain. Nineteen PAHs were investigated in homes and workplaces such as petrol station stores (PSS), an underground parking office and the office of a periodic technical inspection of vehicles (PTI). The range of individual concentrations of PAH collected with the active sampler was from non detected to 144 ng m(-3) at home, from < LOD to 595 ng m(-3) at PSS, from 0.08 to 492 ng m(-3) at parking office and from non detected to 93 ng m(-3) at PTI office. Passive samplers were only employed at homes and the concentration range of PAH was from non detected to 5.1 ng m(-3). Naphthalene was the most abundant PAH in all samples using active samplers while phenanthrene was the most abundant at homes using passive samplers. Total concentrations of measured PAH (EPAH) were as follow: 283 ng m(-3) (home), 217-911 ng m(-3) (PSS), 732 ng m(-3) (parking office) and 216 ng m(-3) (PTI office). Three components were extracted from the application of PCA to the petrol stations stores accounting for 97.2% of the total variance. A procedure to estimate the measurement uncertainty of PAH collected with active samplers has also been developed as it is an important issue in order to achieve accurate measurement results. The relative uncertainties were found to be in the range of 16-45% except for Acenaphthene whose uncertainty was around 54%.