Fig. 2

IR spectra comparison for pure benzo[a]pyrene (red spectrum), \(\:1\:\)wt.\(\:\%\) benzo[a]pyrene adsorbed on hydrated magnesium sulfate (black spectrum) and hydrated magnesium sulfate blank (blue spectrum) in (a) IR \(\:8000-3500\:{cm}^{-1}\) spectral range; (b) IR \(\:3500-450\:{cm}^{-1}\) spectral range. Only adsorbed benzo[a]pyrene bands with shifts greater than the resolution of the instrument (\(\:>4\:{cm}^{-1}\)) with respect to the pure benzo[a]pyrene are shown. Legend: \(\:\nu\:\) stretching vibrations; \(\:{\delta\:}_{ip}\) in-plane bending vibrations; \(\:{\delta\:}_{oop}\) out-of-plane bending vibrations.