Methodology to examine polycyclic aromatic hydrocarbons (PAHs) nitrated PAHs and oxygenated PAHs in sediments of the Paraguaçu River (Bahia, Brazil).

Conventional methods for determination of polycyclic aromatic compounds (PACs) in sediments usually require large sample sizes (grams) and solvent volumes (at least 100 mL) through the employment of Soxhlet extraction, which is both time (hours) and energy consuming, among other disadvantages. We developed a new analytical protocol for the determination of PACs in sediments using microextraction, which requires small sample masses (25 mg), 500 μL of acetonitrile-dichloromethane mix and sonication for 23 min, followed by GC-MS analysis. The method was validated using the certified reference material SRM 1941b - NIST organic marine sediment, as well as internal deuterated standards. Seventeen PAHs, seven nitro-PAHs and one quinone were detected and quantified. The mean concentrations were 90.4 ng g-1 for PAHs, 179.2 ng g-1 for nitro-PAHs and 822.5 ng g-1 for quinones. The proposed method showed good sensitivity, linearity, precision and accuracy for the determination of PAC in sediments samples.