Quantification of monohydroxylated polycyclic aromatic hydrocarbons in human urine samples using solid-phase microextraction coupled with glass-capillary nanoelectrospray ionization mass spectrometry.

Polycyclic aromatic hydrocarbons (PAHs) are environmental contaminants with carcinogenic effect raising worldwide concerns. Hydroxylated PAHs (OH-PAHs) could be formed in the body as metabolites of PAHs in human urine samples and thus considered as biomarkers of PAH exposure. In this study, five OH-PAHs including 3-phenanthrol, 1-naphthol, 2-hydroxy fluorene, 1-hydroxprene and 6-hydroxy chrysene in human urine samples were selectively enriched by C18 solid-phase microextraction (SPME), then SPME fiber was connected high voltage and then was inserted into a glass-capillary to elute and ionize the analytes for mass spectrometric (MS) detection. The coupling of SPME-MS showed excellent analytical performance for detection of urinary OH-PAHs under optimal conditions, providing an easy operation for rapid detection of a single sample within minutes. By use of internal standard (i.e., 2-hydroxy fluorene-d9), the limit of detection (LOD) and limit of quantitation (LOQ) of OH-PAHs were found to be less than 0.05 ng L-1 level (S/N > 3) and less than 0.1 ng L-1 level (S/N > 10), respectively. The dynamic ranges of five OH-PAHs were found to be a range at 0.1-5.0 ng L-1 with excellent coefficient (R2  > 0.99). This method also showed good precisions (intra-day: 3.4-5.5%, inter-day: 7.0-9.8%, n = 5) and good accuracy (85.3-95.3%, n = 5). Moreover, ion suppression and matrix effect in detection of OH-PAHs in urine were also investigated. Human urine samples collected from 12 volunteers including 6 non-smokers and 6 smokers have been successfully analyzed, it was found that individual OH-PAHs in smokers were higher than in non-smokers. This study demonstrated that SPME coupled with glass-capillary nanoESI-MS is a sensitive method for rapid detection of urinary OH-PAHs for health risk assessment of PAHs exposure.