Close overlapping discrimination of polycyclic aromatic hydrocarbons by synchronous scanning at variable-angle solid-phase spectrofluorimetry

The polycyclic aromatic hydrocarbons (PAHs) fluorene, acenaphthene and phenanthrene have been determined in water at trace levels by solid-phase variable-angle synchronous scanning spectrofluorimetry. These PAHs were previously fixed on Sephadex G-15 gel, and then packed in a quartz cell with a 1-mm pathlength. The fluorescence of the PAHs-gel system was measured directly using a solid-surface attachment. The applicable concentration ranges were 0.70–7.00 ng ml−1 for fluorene, 4.0–60.0 ng ml−1 for acenaphthene and 0.50–5.00 ng ml−1 for phenanthrene. The detection limits were 0.07 ng ml−1, for fluorene, 0.4 ng ml−1 for acenaphthene and 0.05 ng ml−1 for phenanthrene, the relative standard deviations being 0.94%, 0.95% and 0.74%, respectively. The method was applied to the determination of the cited PAHs in waters of diverse provenance. The recoveries obtained were 93.0–105.0%.