Abstract

Applications of laser spectroscopy for highly sensitive detection of harmful substances are demonstrated.

• Laser-induced, time-resolved fluorescence applied to aerosol and water. Analytes of interest are polycyclic aromatic hydrocarbons and geological tracer substances. Detection limit is around 10 ppt.

• Laser-induced breakdown spectroscopy for rapid screening of the elemental content of soil, sand, and landfill barrier. The various parameters for signal formation are discussed. Detection limit is around 10 ppm for selected heavy metals.

• Resonant photoacoustic detection of free-flowing particles. Via a modulated diode laser the true light absorption by ultrafine carbon particles is measured in situ. Common to all techniques is proportionality of signal versus laser power. In the case of laser-induced fluorescence the construction of fiber-optical sensors is possible. First applications to real matrices are presented.

© 1994 IEEE