Highly sensitive sequential injection determination of p-aminophenol in paracetamol formulations with 18-molybdodiphosphate heteropoly anion based on elimination of Schlieren effect

► Determination of p-aminophenol with 18-molybdodiphosphate by SIA method. ► A new strategy has been proposed to reduce the Schlieren effect. ► Careful matching of the reagent and buffer concentrations decreases Schlieren effect. ► Using new strategy allowed to improve sensitivity by one order of magnitude. ► Amount as low as 0.001% of p-aminophenol can be determined in paracetamol tablets.