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 Fe3O4/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 R2 > 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.
Keywords: Derivatization Exposome High throughput Hydroxyl polycyclic aromatic hydrocarbons Magnetic dispersive solid phase extraction Multiplexed tags chemical isotope labeling