ULTRAVIOLET MULTIWAVELENGTH ABSORPTIOMETRY (UVMA) FOR THE EXAMINATION OF NATURAL-WATERS AND WASTEWATERS .3. DETERMINATION OF CHROMIUM(VI)

Chromium(VI) is one of the major pollutants of waters and unfortunately, at the present time, it cannot be determined with a simple and fast method. The use of the ultraviolet multiwavelength absorptiometry (UVMA) for chromium determination is very convenient for that purpose because of the well known absorption properties of chromium. Two methods are proposed which lead to different sensitivity. The first one needs hydroxide sodium addition for the measurement of the chromate form and has a detection limit of 4 μg/l. The second does not use any reagent and determines directly both dichromate and chromate forms, whose sum gives the concentration of chromium(VI). This last procedure is faster but the characteristics are slightly less precise. These proposed methods have been compared with a reference method, for natural waters and treated wastewaters, with good agreement. These procedures can be used for water quality monitoring. © 1990 Springer-Verlag.