Determination of nitrated and oxygenated polycyclic aromatic hydrocarbons in water samples by a liquid-liquid phase microextraction procedure based on the solidification of a floating organic drop followed by solvent assisted back-extraction and liquid chromatography-tandem mass spectrometry

摘要

A methodology was optimized for the determination of nitrated-PAHs (nitro-PAHs) and oxygenated-PAHs (oxy-PAHs) in natural waters. The extraction/preconcentration procedure was performed by liquid-liquid phase microextraction based on the solidification of a floating organic drop followed by a novel solvent assisted back-extraction (DLLME-SFO-SBE) combined with liquid chromatography-tandem mass spectrometry. The solvent assisted back extraction into a suitable solvent enabled the direct injection of nitro and oxy-PAHs into the UHPLC-(+)APCI-MS/MS system. Parameters affecting the efficiency of the back-extraction procedure were evaluated and optimized, including the nature of the back-extractant volume, temperature and agitation effect. Additionally, various strategies related to the emulsion formation process were assayed.