Figure 8.
The generation of substrate-derived free radicals from (A) 3-nitro-BaP and (B) 6-nitro-BaP. Samples contained 0.9 mM 3-nitro-BaP or 6-nitro-BaP and 25 mM 5-tert-butoxycarbonyl-5-methyl-1-pyrroline-N-oxide (BMPO) in 90% CH3CN. Samples were irradiated at 382 and 400 nm for 3-nitro-BaP; and 369 and 389 nm for 6-nitro-BaP. ESR signal recorded after 5 and 25 min time intervals. ESR instrument settings were as follows: 20 mW microwave power, 100 G sweep width, 1 G field modulation amplitude, and 100 kHz modulation frequency.