Ground-State Diffuse Reflectance and Laser-Induced Luminescence on the Evaluation of Total PAHs in Urban Air Particulate Matter from Rio de Janeiro City in Brazil

Abstract

Ground-state diffuse reflectance and laser-induced fluorescence techniques were tested on the evaluation of total polycyclic aromatic hydrocarbons (PAHs) in unextracted and unfractionated airborne particulate matter. The total particulate PAH content estimated from these methods and from gas-chromatography in air particulate samples collected in the Rio de Janeiro city and for standard reference material (SRM) 1648, were compared. Ground-state diffuse reflectance proved to be by itself a good technique for estimating total PAH content in urban particulate matter, since results directly correlate with data obtained by conventional gas-chromatographic techniques. Laser-induced fluorescence is also an efficient method for low concentration estimates. Apparent deviations of the fluorescence response do occur due to black carbon interference and have to be taken into account. These surface optical methods showed to be fast, low cost, sensitive and useful as screening techniques, allowing field measurements.

Keywords

• air quality monitoring techniques
• air particulate matter
• polycyclic aromatic hydrocarbons
• ground-state diffuse reflectance
• laser-induced fluorescence