New determination scheme of p-aminophenol by using MnO2 as a preoxidant is demonstrated in this work. In the flow injection system, the p-aminophenol is oxidized to quinoneimine by MnO2 at up-stream, which can be detected at a suitable reductive potential. After optimization, the linear range of PAP is started from 1 μM to 30 μM (R2=0.999), the estimated detection limit (S/N=3) is 0.28 μM. Two real samples are studied and excellent recoveries are achieved by using standard addition method.
