The determination of occupational exposure to polycyclic aromatic hydrocarbons by the analysis of 1-hydroxypyrene in urine using a simple automated online column switching device and high-performance liquid chromatography.

An analytical method using a liquid chromatograph combined with a simple online column switching sample pre-treatment system was developed for the determination of 1-hydroxypyrene (1-HP) in urine. This compound is the metabolite of pyrene and is used to assess the exposure of workers to polycyclic aromatic hydrocarbons (PAHs). After enzymatic hydrolysis, a urine sample was directly injected into a high-performance liquid chromatograph (HPLC) where it automatically underwent a sample cleanup using a column switching device. The procedure is simpler than previous methods because it uses only one switching valve, one extraction column and one HPLC pump. The analyte was retained on a short extraction column and after interferences were eluted to waste, was subsequently switched onto the analytical column. This allowed a short analysis time of 15 min. The calibration graph was found to be linear within the concentration range of 0.5 to 20 µg/L with a coefficient of determination exceeding r(2) = 0.99. Recoveries were found to be greater than 96% in the range 1 to 10 µg/L with intermediate precision of 2.5 to 5.8% relative standard deviation. This online method was verified by a comparison with an existing manual method by the analysis of 81 urine samples from workers exposed to PAHs and showed that the test results from both methods were in agreement with a probability obtained from the paired Student's t-test of P > 0.76. The proposed online method was found to be simple, fast and suited to routine analyses of 1-HP in urine for the assessment of occupational exposure to PAHs.