title: Condensed Phase Membrane Introduction Mass  Spectrometry with Direct Electron Ionization: On-line  Measurement of PAHs in Complex Aqueous Samples.
abstract: Polycyclic aromatic hydrocarbons (PAHs) are USEPA regulated priority pollutants. Their low aqueous solubility requires very sensitive analytical methods for their detection, typically involving preconcentration steps. Presented is the first demonstrated ‘proof of concept’ use of condensed phase membrane introduction mass spectrometry (CP-MIMS) coupled with direct liquid electron ionization (DEI) for the direct, on-line measurement of PAHs in aqueous samples. DEI is very well suited for the ionization of PAHs and other nonpolar compounds, and is not significantly influenced by the co-elution of matrix components. Linear calibration data for low ppb levels of aqueous naphthalene, anthracene, and pyrene is demonstrated, with measured detection limits of 4 ppb. Analytical response times (t10%–90% signal rise) ranged from 2.8 min for naphthalene to 4.7 min for pyrene. Both intra- and interday reproducibility has been assessed (<3% and 5% RSD, respectively). Direct measurements of ppb level PAHs spiked in a variety of real, complex environmental sample matrices is examined, including natural waters, sea waters, and a hydrocarbon extraction production waste water sample. For these spiked, complex samples, direct PAH measurement by CP-MIMS-DEI yielded minimal signal suppression from sample matrix effects (81%–104%). We demonstrate the use of this analytical approach to directly monitor real-time changes in aqueous PAH concentrations with potential applications for continuous on-line monitoring strategies and binding/adsorption studies in heterogeneous samples.
authors.affiliation: 1Laboratorio LC-MS, Dipartimento di Scienze della Terra, della Vita e dell’Ambiente (DiSTeVA), Università degli studi di Urbino Carlo Bo, Urbino, Italy
authors.forename: Veronica
authors.initials: V
authors.lastname: Termopoli
authors.forename: Giorgio
authors.initials: G
authors.lastname: Famiglini
authors.forename: Pierangela
authors.initials: P
authors.lastname: Palma
authors.forename: Achille
authors.initials: A
authors.lastname: Cappiello
authors.forename: Gregory W
authors.initials: GW
authors.lastname: Vandergrift
authors.forename: Erik T
authors.initials: ET
authors.lastname: Krogh
authors.forename: Chris G
authors.initials: CG
authors.lastname: Gill
mesh_terms: D002138:Calibration; D004867:Equipment Design; D006108:Graphite / Q000737:chemistry; D013058:Mass Spectrometry / Q000295:instrumentation / Q000379:methods*; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis*; D015203:Reproducibility of Results; D012623:Seawater / Q000032:analysis / Q000737:chemistry; D012680:Sensitivity and Specificity; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D011084:Polycyclic Aromatic Hydrocarbons; D014874:Water Pollutants, Chemical; D006108:Graphite