Selective immunoclean-up followed by liquid chromatography for the monitoring of a biomarker of exposure to polycyclic aromatic hydrocarbons in urine at the ng l−1 level

A selective clean-up procedure using an immunosorbent (IS) was developed for the trace-level determination, in water and urine samples, of 3-benzo(a)pyrene-glucuronide (3-BP-G), a biomarker of exposure to carcinogenic polycyclic aromatic hydrocarbons (PAHs). First, three sorbents used for the immobilization of antibodies were evaluated for their ability to limit the risk of non-specific interactions and to provide a high bonding density. The best sorbent, i.e. sepharose, was used for the immobilization of two different monoclonal antibodies. The most specific antibody for 3-BP-G was applied to the selective extraction from urine providing a clean extract, an easy and reliable quantification by comparison with a classical SPE process. The sensitivity of the fluorescence associated with the selectivity of the IS provides a limit of detection up to 1.2 ng l−1 in urine for 3-BP-G.