Pyrophosphate is used as a stabilizer in aqueous hydrogen peroxide solution. “Reagent grade” solutions may contain pyrophosphate in the higher mg/L range, while “electronic grade” hydrogen peroxide should be free of this stabilizer. Here the determination of pyrophosphate in a high purity H2O2 solution (30%) is performed applying Inline Preconcentration with Matrix Elimination (MiPCT-ME) and a Dose-in Gradient.