Inhibitory spectrophotometric determination of trace phenol based on the oxidizing decoloration reaction of butyl Rhodamine B by potassium bromate

The decolorizing reaction based on incubation effect of phenol to oxidation butyl rhodamine B with potassium bromate has been investigated in sulfuric acid medium by stop-flow technique. The reaction mechanism has been discussed. A highly sensitive and simple inhibitory kinetic spectrophotometric method for the determination of trace phenol based on its effect on incubation period of the reaction was proposed. The detection limit was 1.3×10+{-9} g/L and linear range was 0.3~15.0 μg/L and the relative standard deviation (5.0 μg/L, n=11) was 2.1% for phenol. The method has been applied to determining of trace phenol in samples of river waters and industrial wastewater with satisfactory results.