Determination of oxygenated polycyclic aromatic hydrocarbons in atmospheric aerosol samples by liquid chromatography-tandem mass spectrometry

In this paper, the development of an analytical method using liquid chromatography-tandem mass spectrometry (LC-MS-MS) with atmospheric pressure chemical ionization (APCI) for the determination of 17 oxygenated polycyclic aromatic hydrocarbons (OPAH) is described. These OPAH include ketones, pyrones and diketones. The APCI interface parameters have been optimized for maximum sensitivity. Positive ion mode was proved to be most sensitive for ketones and pyrones while negative ion mode gave better detection limits for target diketones. The detection limits of the method ranged from less than 1.20 μg L^-1 for several OPAH solutions (between 0.10 and 0.70 μg L^-1 for positive mode and between of 0.19 and 1.20 μg L^-1 for negative mode). The analytical method was applied particulate matter (PM_2.5) samples collected over 24-48 h periods between March 2005 and June 2005 in Tempe (Arizona, USA). Before analysis aerosol samples were solvent extracted and concentrated to a final volume of 1 mL of methanol. OPAH concentrations observed for this urban site ranged from 0.22 to 3.60 ng m^-3.