Design of a method for polycyclic aromatic hydrocarbons routine determination by liquid-liquid microextraction and GC-MS/MS: Optimisation and validation

Abstract

This study focuses on the optimisation and validation of a method for the determination of Polycyclic Aromatic Hydrocarbons (PAHs) to be applied in real supply waters of the Zaragoza area. The supply water samples were analysed by gas chromatography coupled to tandem mass spectrometry using ion trap (GC-MS/MS IT) due to its great selectivity and sensitivity. Injections in GC were performed by programmable temperature vaporization (PTV) in solvent venting mode of the samples. A liquid-liquid microextraction (LLME) treatment was necessary to concentrate the sample for analysis. Moreover, in order to correct matrix effects, Isotopically-Labelled Internal Standard (ILIS) was added to the samples. Several experiments were carried out to optimise the PAHs extraction method, chromatography and MS/MS conditions. The study focused mainly on Acenaphthylene and Acenaphthene as these compounds were not included in the method in use at Valero Analítica. In addition, the research also focused on Benzo(𝛽)fluoranthene, Benzo(g,h,i)perylene, Benzo(𝜅)fluoranthene and Indeno(1,2,3-c,d)pyrene, compounds regulated by RD 140/2003. The results of this work indicate that a comprehensive study of the PAHs of interest can be performed on the optimised method. The validation provides positive data for all compounds except for Acenaphthylene and Acenaphthene, which have an (limit of quantification) LOQ more than three times higher than the rest of PAHs. The results of this study contribute to report more complete PAHs data and therefore to understand which compounds are found in drinking water.