Aerosol photoemission for quantification of polycyclic aromatic hydrocarbons in simple mixtures adsorbed on carbonaceous and sodium chloride aerosols.

The photoelectric aerosol sensor was applied as a tool for the in situ and on-line detection of surface-enriched polycyclic aromatic hydrocarbons (PAHs). Carbon aerosol and sodium chloride aerosol were coated stepwise with up to four different PAHs or simultaneously with three different PAHs (internally mixed aerosol). The measured photoelectric signal of the internally mixed aerosol was compared with the expected signal, which was calculated from the previous calibration of the sensor. An additivity of the individual contributions of the absorbed PAHs on the sum signal was found. Experiments with photoelectrically inactive paraffin adsorbed on photoelectrically active aerosol particles have demonstrated that only the surface composition contributes to the photoemission signal.