Direct quantification of monohydroxy-polycyclic aromatic hydrocarbons in synthetic urine samples via solid-phase...

A screening method for six biomarkers from polycyclic aromatic hydrocarbons (PAH) exposure in urine samples is presented. Solid-phase extraction is carried out on commercial C18 cartridges via an optimized procedure that minimizes metabolite loss. PAH metabolites are directly determined in the eluting solvent (3 mL of methanol) without the need of previous solvent evaporation. Spectral overlapping is resolved with the combination of unfolded partial least squares and residual bilinearization. Excellent analytical figures of merit were obtained for all the studied metabolites. Analytical recoveries varied between 87.9% (9-hydroxyphenanthrene) and 99.4% (3-hydroxybenzo[a]pyrene). For 10 mL of urine sample, the limits of detection varied between 0.01 ng.mL(-1) (3-hydroxybenzo[a]pyerene and 1-hydroxybenzopyrene) and 0.3 ng.mL(-1) (2-hydroxynaphthalene). Because the chemometric algorithm is capable of handling more than six metabolites at once, the application of this approach to a larger number of metabolites is feasible.