Pressurized liquid extraction technique for the analysis of pesticides, PCBs, PBDEs, OPEs, PAHs, alkanes, hopanes, and steranes in atmospheric particulate matter

• PLE technique for the analysis of 130 target analytes from a single filter aliquot.
• Method allows for more fully characterized atmospheric particulate matter.
• 92 target analytes identified in Houston atmospheric particulate matter.
• First identification of OPEs (emerging class of flame retardants) in Houston air.

An analytical method has been developed for the pressurized liquid extraction (PLE) of a wide range of semi-volatile organic compounds (SVOCs) from atmospheric particulate matter. Approximately 130 SVOCs from eight compound classes were selected as molecular markers of (1) agricultural activity (30 current and historic-use pesticides), (2) industrial activity (18 PCBs), (3) consumer products and building materials (16 PBDEs, 11 OPEs), and (4) motor vehicle exhaust (22 PAHs, 16 alkanes, 9 hopanes, 8 steranes). Currently, there is no analytical method validated for the extraction of all eight compound classes in a single automated technique. The extraction efficiencies of varying solvents and solvent combinations at high temperatures and pressures were examined. Extracts were concentrated and analyzed by gas chromatography coupled with mass spectrometry. The optimized PLE method utilized methylene chloride:acetone (2:1 v/v) at 100 °C with three (5 min) static cycles, flush volume of 80%, and a 100 s N2 purge. Spike and recovery experiments (n = 7) provided average percent recoveries for pesticides, PCBs, PBDEs, OPEs, PAHs, alkanes, hopanes, and steranes of 88.8 ± 4.0%, 86.9 ± 2.6%, 83.8 ± 2.9%, 101 ± 6%, 90.3 ± 6.1%, 74.4 ± 8.8%, 104 ± 8%, and 86.5 ± 8.6%, respectively. The developed method was applied to atmospheric particulate matter samples collected in the greater Houston, TX metropolitan area. Ambient concentrations of eight classes of compounds (92 SVOCs) were reported in pg m−3.