Simultaneous determination of multiple isomeric hydroxylated polycyclic aromatic hydrocarbons in urine by using ultra-high performance liquid chromatography tandem mass spectrometry

Monitoring the level of hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) in urine is the key to exploring human metabolic changes and comprehensive potential toxicity of PAHs. The OH-PAHs with isomeric structure have different biological functions, indicating that their quantification is indispensable. However, the quantitation method is still dissatisfactory due to the poor separation of these isomeric OH-PAHs. The current study established a ultra-high performance liquid chromatography (UHPLC) tandem mass spectrometry (MS) method to complete the simultaneous determination of 17 OH-PAHs, including two naphthalene metabolites (1-hydroxynaphthalene, 2-hydroxynaphthalene), two fluorene metabolites (2-hydroxyfluorene, 3-hydroxyfluorene), five phenanthrene metabolites (1-hydroxyphenanthrene, 2-hydroxyphenanthrene, 3-hydroxyphenanthrene, 4-hydroxyphenanthrene, 9-hydroxyphenanthrene), a pyrene metabolite (1-hydroxypyrene), five chrysene metabolites (1-hydroxychrysene, 2-hydroxychrysene, 3-hydroxychrysene, 4-hydroxychrysene, 6-hydroxychrysene) and two benzo[a]pyrene metabolites (3-hydroxybenzo[a]pyrene, 9-hydroxybenzo[a]pyrene). The method validation results showed good selectivity, linearity (r2 > 0.999), inter-day and intra-day precision (relative standard deviation (RSD) < 5.5% and RSD < 6.3%), stability (RSD < 19.3%), matrix effect (-8.3%-11.5%) and recovery (65.9%-116.2%). This method is convenient, sensitive and efficient, saving expensive materials and complicated derivatization procedures. The practical applicability of developed approach was also tested in urine samples to identify potential biomarkers of PAHs exposure in humans, and a great compromise was obtained between recoveries and extract convenience. The developed approach may be widely utilized for specific determination of OH-PAHs with isomer structure in urine samples. It is expected that the application of this method may provide powerful references for PAHs exposure assessment.