Spectrophotometric determination of paracetamol in drug formulations by oxidation with potassium dichromate.

A rapid spectrophotometric method for determination of paracetamol is described, based on oxidation with dichromate for 15 min in 6M sulphuric acid at 80 degrees , and measurement (at 580 nm) of the chromium(III) formed. The method is applied to the determination of paracetamol in drugs prescribed for colds, coughs and flu. Of the common pharmaceuticals associated with paracetamol, only ascorbic acid and acetylsalicylic acid interfere. The results have been statistically compared with those obtained by the official (BP) and cerium(IV) methods.