A portable absorption-fluorometer for detection of organic substances in fluids

• Published in: Analytical and bioanalytical chemistry Vol. 355; no. 5-6; pp. 742 - 744
• Main Authors: Mittenzwey, K H, Sinn, G, Hiersigk, R, Krause, M, Lenz, P, Pfeil, L, Rauchfuss, J, Streich, G
• Format: Journal Article
• Language: English
• Published: Germany 01.06.1996
• DOI: 10.1007/s0021663550742
• ISSN: 1618-2642

Using the method of multipath-saturation fluorescence, which considers both fluorescent as well as nonfluorescent substances, the total absorption coefficient can be determined with high sensitivity. This new fluorescence 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 in 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 been performed with drinking water samples defined polluted by non-fluorescent p-nitrophenol and 2-nitroaniline. Based on the method of multipath-saturation fluorescence a good correlation to the substance concentration was achieved, whereas the conventional absorption failed.