Automated column-switching high-performance liquid chromatography method for the determination of 1-hydroxypyrene in...

An on-line sample treatment method to determine 1-hydroxypyrene (1-OHP), a metabolite of polycyclic aromatic hydrocarbons (PAHs), in human urine has been developed. The hydrolysed biological fluid was directly injected into the chromatographic system after only centrifugation. A miniature precolumn loop packed with a preparative phase and coupled on-line to a liquid chromatographic (LC) system was used for analyte enrichment. The analytes were non-selectively desorbed with the LC eluent and cleaned by means of a column-switching procedure comprising two purification columns and an analytical column. Pre-treatment and analysis were performed within 2 and 20 min, respectively. Average 1-OHP recovery reached 99% in the 1-25 microg/l range of urine, and the quantitation limit was 20 ng/l for 100 microl of injected sample. A comparison with a more time-consuming off-line method was performed by analysing 120 urine samples of PAH-exposed and expected unexposed workers; the statistical treatment indicated that both methods are in agreement.