The development of a new inhibition kinetic spectrophotometric method for determination of phenylhydrazine

A new sensitive kinetic method has been developed for the determination of trace amounts of phenylhydrazine in the range of 1.08 X 10(-7) to 1.08X 10(-6) g/cm(3). The detection limit of this method is 0.008 mu g/cm(3), based on the 3Sb criterion. The method is based on the inhibitory effect of phenylhydrazine on the oxidation of Victoria Blue 4-R by KBrO3. The reaction was monitored spectrophotometrically at 596.3 nm. The method development includes the optimization of the reagent concentration and temperature. The kinetic parameters of the reaction are reported and a rate equation is suggested. The effects of certain foreign ions upon the reaction rate were determined for the assessment of the selectivity of the method. The new developed method was found to have fairly good selectivity, sensitivity, simplicity and rapidity.