Solid-phase nano-extraction and laser-excited time-resolved Shpol\u27skii spectroscopy for the analysis of polycyclic aromatic hydrocarbons in drinking water samples

A unique method for screening polycyclic aromatic hydrocarbons in drinking water samples is reported. Water samples (500 mu l) are mixed and centrifuged with 950 mu l of a commercial solution of 20 nm gold nanoparticles for Pollutants extraction. The precipitate is treated with 2 mu l of 1-pentanethiol and 48 mu l of n-octane, and the Supernatant is then analyzed via laser-excited time-resolved Shpol\u27skii spectroscopy. Fifteen priority pollutants are directly determined at liquid helium temperature (4.2 K) with the aid of a cryogenic fiber-optic probe. Unambiguous pollutant determination is carried out via spectral and lifetime analysis. Limits of detection are at the parts-per-trillion level. Analytical recoveries are similar to those obtained via high-performance liquid chromatography. The simplicity of the experimental procedure, use of microliters of organic solvent, short analysis time, selectivity, and excellent analytical figures of merit demonstrate the advantages of this environmentally friendly approach for routine analysis of numerous samples. (C) Published by Elsevier Inc