Colorimetric determination of trace pollutants in water using photothermal deflection spectroscopy

Summary form only given. Photothermal deflection spectroscopy (PDS) is a well-known technique for measuring small absorbencies in gases, liquids, and solids (<10/sup -6/). The basic principle of this technique are relatively simple. A pump laser passes through a medium and is partially absorbed. A fraction of the absorbed energy is released as heat, which results in a spatially and temporally modified refractive index field. The photoinduced refractive index change can be monitored through the deflection of a probe beam.