Quantification of Nitro-PAHs and PAHs

In this work, we used as authentic nitro-PAH standards a NIST SRM 2265 (polycyclic aromatic hydrocarbons nitrated in methylene chloride II), which contained 2-nitrofluoranthene (2-NFLT, CAS# 13177-29-2), 3-nitrofluoranthene (3-NFL, CAS# 892-21-7), 1-nitropyrene (1-NPYR, CAS# 5522-43-0), 2-nitropyrene (2-NPYR, CAS# 789-07-1), and 3-nitrobenzanthrone (3-NBA, CAS# 17117-34-9), among others. Their certified concentrations were 5.46 ± 0.15 µg mL⁻¹ (2-NFLT), 6.14 ± 0.13 µg mL⁻¹ (3-NFLT), 6.91 ± 0.27 µg mL⁻¹ (1-NPYR), 6.91 ± 0.27 µg mL⁻¹ (2-NPYR), and 4.39 ± 0.11 µg mL⁻¹ (3-NBA). Since SRM 2265 does not include 2-nitrobenzanthrone (2-NBA, CAS# 111326-48-8), this compound was purchased from Sigma-Aldrich (USA) (>99% purity) and added to that. Authentic standards for fluoranthene (FLT, CAS# 206-44-0), pyrene (PYR, CAS# 129-00-0), benzo[a]pyrene (BaP, CAS# 50-32-8), and benzo[a]anthracene (BaA, CAS# 56-55-3), among others, are included in the EPA 610 PAH mix, at 2000 µg mL⁻¹ each, in methanol: methylene chloride (1:1) (Supelco, USA). In this study, stock and analytical solutions were prepared by successive dilutions in acetonitrile (chromatographic and spectroscopic grade, J.T. Baker, USA).