A PORTABLE ABSORPTION-FLUOROMETER FOR DETECTION OF ORGANIC-SUBSTANCESIN FLUIDS

Using the method of multipath-saturation fluorescence, which considers both fluorescent as well as nonfluorescent substances, the total abso rption coefficient can be determined with high sensitivity. This new f luorescence method is appropriate, e.g. for in-situ applications. Thus a portable absorption-fluorometer has been constructed. The main part of the device is a multireflection cell based on a design of Herriott with a 1 cm quartz-cuvette. Two pairs of spherical dielectric mirrors are used to realize the multireflection of the excitation radiation i n the UV and blue spectral range. The combination of a cylindrical and a convace mirror leads to a long pathway of the excitation radiation and, thus, to a full absorption by the fluid. A first experiment has b een performed with drinking water samples defined polluted by non-fluo rescent p-nitrophenol and 2-nitroaniline. Based on the method of multi path-saturation fluorescence a good correlation to the substance conce ntration was achieved, whereas the conventional absorption failed.