Determination of EPA's priority pollutant polycyclic aromatic hydrocarbons in drinking waters by solid phase extraction-HPLC

Abstract

A solid phase extraction (SPE) coupled with a liquid chromatographic procedure with fluorimetric detection was established for the determination of PAHs, priority pollutants listed by EPA (acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, dibenzo(a,h)anthracene, benzo(g,h,i)perylene, indeno(1,2,3-c,d)pyrene) in waters intended for human consumption. Acting on wavelengths detection, significant improvements on limits of quantitation were achieved: worthy of note is the 40-fold enhancement of sensitivity obtained for benzo(g,h,i)perylene, whose concentration is regulated by the European Community (EC) Directives. The SPE procedure was optimized for some parameters including solvent volumes for cartridge conditioning, sample volumes, presence of methanol in the sample, obtaining significant recovery enhancement also for low-boiling PAHs, phenanthrene and anthracene, whose determination is hampered by their high vapor pressure and Henry's law constant values. Advantages of this procedure are low quantitation limits (0.04–1 ng L⁻¹), reduced solvent volumes used (and disposed), reduced analysis times that enable the processing of 24 samples per day, and a lower cost of the whole analysis. The whole analysis protocol enabled the determination of PAHs in drinking waters at concentrations lower than 1 ng L⁻¹, two orders of magnitude lower than what is currently required by the EC Directive. The protocol derived was validated for its accuracy inside an inter-laboratory study and it is now currently routinely applied for PAHs analysis by the laboratory in charge of monitoring drinking water in the Italian city of Torino.