Determination of paracetamol in pharmaceutical formulations using a sequential injection system

A simple method for the rapid determination of paracetamol in pharmaceutical formulations is described. The method involves oxidation of paracetamol by potassium hexacyanoferrate(III) and a subsequent reaction with phenol in the presence of ammonia. The blue complex formed is measured at 630 nm. The system has a sample frequency of 27 samples per h with a detection limit of 0.2 mg l(-1) The calibration curve is linear up to 60 mg l(-1) with a relative standard deviation of 1.2% (n = 10). (C) 2002 Elsevier Science B.V. All rights reserved.