title: Novel determination of polychlorinated naphthalenes in water by liquid chromatography-mass spectrometry with atmospheric pressure photoionization.
abstract: This study presents the development, optimization, and validation of a novel method for the determination of polychlorinated naphthalenes (PCNs) by liquid chromatography-atmospheric pressure photoionization (APPI), using toluene as dopant. The mass spectra of PCN 52, 54, 66, 67, 73, and 75 were recorded in negative ionization. The base ions corresponded to [M-Cl+O](-), where M is the analyte molecule. A strategy, which includes designs of experiments, for the development, the evaluation, and the optimization of the LC-APPI-MS/MS methods is also described. Finally, a highly sensitive method with low instrumental limits of detection (LoDs), ranging from 0.8 pg for PCN 75 to 16 pg for PCN 54 on column, was validated. A Thermo Hypersil Green PAH (100 mm × 2.1 mm, 3 μm) column was used with acetonitrile/water/methanol as mobile phase. The method was applied for the determination of the selected PCNs in surface and tap water samples. A simple liquid-liquid extraction method for the extraction of PCNs from water samples was used. Method LoQs ranged from 29 ng L(-1), for PCN 73, to 63 ng L(-1), for PCN 54, and the recoveries ranged from 97 to 99%, for all congeners. This is the first LC-APPI-MS/MS method for the determination of PCNs in water samples.
authors.affiliation: Laboratory of Analytical Chemistry, Department of Chemistry, School of Sciences, National and Kapodistrian University of Athens, Panepistimioupolis Zografou, 157 71, Athens, Greece.
authors.forename: Athanasios I
authors.initials: AI
authors.lastname: Moukas
authors.affiliation: Laboratory of Analytical Chemistry, Department of Chemistry, School of Sciences, National and Kapodistrian University of Athens, Panepistimioupolis Zografou, 157 71, Athens, Greece. ntho@chem.uoa.gr.
authors.forename: Nikolaos S
authors.initials: NS
authors.lastname: Thomaidis
authors.affiliation: Laboratory of Analytical Chemistry, Department of Chemistry, School of Sciences, National and Kapodistrian University of Athens, Panepistimioupolis Zografou, 157 71, Athens, Greece.
authors.forename: Antony C
authors.initials: AC
authors.lastname: Calokerinos
keywords: Atmospheric pressure photoionization (APPI); Dopant; Experimental design; LC-APPI-MS/MS; Polychlorinated naphthalenes (PCNs); Pseudo-SRM