Simultaneous Determination of p-Dihydroxybenzene and o-Phenylenediamine by Inhibitory Kinetic Spectrophotometry with Artificial Neural Networks

In acidic medium,Fe(Ⅲ) could catalyze the reaction of H2O2 oxidation of neutral red fading,while p-dihydroxybenzene and o-phenylenediamine can inhibit the catalysis oxidation reaction rate of fading.But there was some obvious difference in their reaction rates.And their absorbance additive properties were not satisfactory.The new method for the simultaneous determination of p-dihydroxybenzene and o-phenylenediamine was established by inhibitory kinetics spectrophotometry with artificial neural network.The optimum conditions of reaction and determination were studied as follows:1.0×10-3mol·L-1 neutral red dosage of 0.8mL,30% H2O2 dosage of 0.6mL,standard solution Fe(Ⅲ)(0.100g·L-1) of 0.5mL,0.06mol·L-1HCl dosage of 0.8mL,reaction time of 6min and temperature of 75℃,that was applied to determination of p-dihydroxybenzene and o-phenylenediamine in mixed samples and water samples.The recovery of p-dihydroxybenzene and o-phenylenediamine in mixed samples were 95.6%—104.0% and 97.8%—104.4% respectively.The relative standard deviations of p-dihydroxybenzene and o-phenylenediamine were 3.2% and 2.5% for five replicate determinations.The recovery of standard addition in water sample for the method were both 105%.