Shpolʹskii spectroscopy at the interface of two non-polar microenvironments: a novel approach for the analysis of polycylic aromatic compounds

This article presents a thorough investigation of quantitative parameters for the analysis of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and polychlorinated dibenzofurans (PDBFs) partitioning between an octadecyl silica extraction membrane and microliters of an n-alkane solvent spiked on the surface of the membrane. Shpolʹskii spectrometry is directly performed on the surface of the membrane with the aid of a cryogenic fiber optic probe. The analyte concentration in the layer of Shpolʹskii solvent follows a linear relationship with the analyte concentration in the water sample and the same is observed for the phosphorescence signal of the cryogenic probe. The accuracy and precision needed for quantitative analysis in aqueous samples is demonstrated. The analytical figures of merit show the feasibility to determine organic pollutants at the parts-per-trillion level with minimum solvent consumption.