Determination of 10 Kinds of Monohydroxylated Polycyclic Aromatic Hydrocarbons in Human Urine by Supported Liquid Extraction Followed by Liquid Chromatography-Tandem Mass Spectrometry

The monitoring of urinary monohydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) can be used for the risk assessment of human exposure to polycyclic aromatic hydrocarbons (PAHs). In this work, we developed and optimized a new pretreatment method based on solid-phase supported liquid-liquid extraction (SLE). After pretreatment, the analytes were then determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Urine samples were extracted with a mixed solution of dichloromethane and n-hexane (3:7, V/V) by a SLE clean-up using a diatomaceous earth mini-cartridge. The results indicated that the developed pretreated procedure had good recoveries and also significantly reduced the interference of biological matrix. At three concentration levels (10, 50 and 100 mu g/L), the recoveries of ten OH-PAHs ranged from 88.5% to 120.9%, and the repeatability ranged from 1. 6% to 8. 1%. The limits of detection ranged from 0.06 mu g/L to 0.3 mu g/L and the limits of quantitation were between 0.2 mu g/L and 1.0 mu g/L. This method was finally successfully applied to the determination of OH-PAHs in urines collected from primary school students in Guangdong. The results showed that 2-OHN was the dominant compound, with the highest concentration of 4.83 mu g/L.