Untargeted approach for the evaluation of anthropic impact on the sheltered marine area of Portofino (Italy)

Abstract

Seawater passive sampling with Polar Organic Chemical Integrative Samplers (POCIS) combined with Gaschromatography-Mass Spectrometry analysis were employed as a tool for screening unknown contaminants in a complex Ligurian marine coastal area. The untargeted approach allowed recognizing different classes of compounds, mainly hydrocarbons from C₂₀ to C₃₀. Besides, two chemicals, deriving from anthropic activities, N-butylbenzenesulfonamide (NBBS) and diphenyl sulfone (DPS), were identified and quantified in all samples. Both analytes showed decreasing concentrations from the more confined site to the outer one. The oceanographic characterization of the area performed with multiparametric probes provided useful information, in agreement with chemical analyses. The presence of NBBS and DPS in the site presenting lower continental inputs demonstrated the usefulness of the integrative sampling approach for temporal and spatial monitoring, especially for low level and/or short-term pollution events that traditional monitoring can fail to detect.

Keywords: GC-MS; Ligurian sea; Marine protected area; Passive sampling; Seawater; Trace contaminants.