Luping Sun,Shuyun Zhu,Zhenjia Zheng,Jing Sun,Xian-En Zhao,Huwei Liu
Hydroxyl-polycyclic aromatic hydrocarbons (OH-PAHs) are biomarkers for assessing the exposure levels of polycyclic aromatic hydrocarbons (PAHs). A series of stable isotope mass tags (SIMT-332/338/346/349/351/354/360/363/374/377) were firstly designed and synthesized to perform multiplexed stable isotope labeling derivatization (MSILD) of OH-PAHs in human plasma and urine. Their derivatives were enriched and purified by magnetic dispersive solid phase extraction (MDSPE) using prepared Fe 3 O 4 /GO and then determined by ultra high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) in multiple reaction monitoring mode. 9-Plexed MSILD reagents were prepared using pipemidic acid as core structure with different isotope mass tags, in which carbonyl chloride group was used to label OH-PAHs. The SIMT-346 labeled OH-PAHs standards were used as internal standards, which can greatly increase the quantitative accuracy. 9-Plex labeled nine different real samples can be quantified by UHPLC-MS/MS in a single run. Under optimized MSILD-MDSPE conditions, good linearities of seven OH-PAHs were obtained with satisfactory coefficient of determination R 2 > 0.991. Limits of detection (LODs) of seven OH-PAHs were from 0.1 to 0.5 pg/mL, and limits of quantitation (LOQs) ranged from 0.5 to 2.0 pg/mL. The intra- and inter-day precisions ranged in 2.3–12.4% with accuracies in the range of 91.7–108.4%. Acceptable results of matrix effect (89.7–105.7%) and derivatization efficiency (> 96.4%) were obtained. In short, the developed method has been proved to be high-throughput, sensitive, accurate and easy-handling. This method was applied for the measurement of seven free OH-PAHs in human urine and plasma, and expected to provide technical support for the evaluation of PAHs exposure levels in humans.
The metabolism of polycyclic aromatic hydrocarbons (PAHs) and the elimination kinetics of their mono-hydroxylated metabolites (OH-PAHs) following single exposure to different combinations of four PAHs (PAH4) were studied. Male Sprague–Dawley rats were orally exposed to a single dose of benzo[a]pyrene (B[a]P) or PAH2 (B[a]P + chrysene), PAH3 (B[a]P + chrysene + benz[a]anthracene), and PAH4 (B[a]P + chrysene + B[a]A + benzo[b]fluoranthene) with each combination adjusted to the same dose of individual compound. OH-PAHs including 3-hydroxybenzo[a]pyrene, 3-hydroxychrysene, 3-hydroxybenz[a]anthracene, and 1-hydroxypyrene (1-OHP) were detected in serum and urine samples collected at six intervals over a 72-h period post-dosing. The hepatic mRNA levels of cytochrome P450 (CYPs) were determined to ascertain the expression induction of PAHs metabolic enzymes. Results showed OH-PAHs (except 1-OHP) peaked within 8 h in serum and were excreted from urine within 24–48 h. The serum and urinary concentration of 3-hydroxybenzo[a]pyrene was significantly increased after PAH4 exposure compared with other PAHs combinations. Inversely, urinary concentration of 3-hydroxychrysene was decreased after PAH4 exposure, and the kinetics of 3-hydroxybenz[a]anthracene or 1-OHP were not different depending on the PAHs combinations. Also, CYPs were markedly induced by PAHs. Notably, the induction levels of CYP1A1 and CYP1B1 were significantly higher after PAH4 exposure compared with B[a]P exposure. The results indicated the metabolism of B[a]P was accelerated after PAH4 exposure which might be partly due to the induction of CYPs. These results confirmed PAHs are rapidly metabolized and suggested potential interactions of PAHs may happen among PAH4 mixture.