Supramolecular solvent-based high-throughput sample treatment platform for the biomonitoring of PAH metabolites in urine by liquid chromatography-tandem mass spectrometry

Abstract

Monohydroxylated polycyclic aromatic hydrocarbons (OH-PAHs), present in human urine at trace concentrations (viz. from ng L1 to mg L1 ), are considered the main biomarkers of human exposure to PAHs. In this work, we report a simple and high-throughput sample treatment platform to facilitate the biomonitoring of OH-PAHs by making it easier, greener and most cost-effective. This platform is based on the integration of analyte extraction and sample cleanup in a single step by the use of supramolecular solvents with restricted access properties (SUPRAS-RAM). The SUPRAS was spontaneously formed in situ in the urine by the addition of a colloidal suspension of decanoic acid in THF. Metabolites from naphthalene, fluorene, phenanthrene and pyrene were quantitatively extracted (absolute recoveries in the range 91e109%). Polysaccharides and proteins in the urine were excluded from extraction by physical and chemical mechanisms, which allowed the direct analysis of the SUPRAS extract by liquid chromatography tandem mass spectrometry. Absolute matrix effects for OH-PAHs were in the range 92e103%. Method quantification limits for OH-PAHs, without the need for evaporation of the SUPRAS extracts, were in the interval 1.0e6.7 ng L1 . The precision, evaluated in terms of repeatability and reproducibility, varied between 1.1 and 13.8%. The method was successfully applied to the analysis of urine from 16 smoking and non-smoking volunteers. Both analytical and operational features of this method make it suitable to evaluate human exposure to PAHs.