DETERMINATION OF MICRO AMOUNT OF PARACETAMOL IN PHARMACEUTICAL PREPARATIONS BY MOLECULAR SPECTROPHOTOMETRIC METHOD

Abstract

A simple and sensitive spectrophotometric method has been established for the determination of paracetamol. The method is based on the reaction of paracetamol with iron(III) sulfate. The produced iron(II) reacts with potassium hexacyanoferrate (III) forming Prussian blue colored product with a maximum absorption at 710 nm. Linearity was in the range 0.1 – 7.0 µg mL-1 paracetamol [2.5 – 175.0 µg / 25 mL] with a limit of detection (signal : noise = 3) of 0.038 µg mL-1, a molar absorptive of 3.477 × 104 L mol-1 cm-1, a Sandell sensitivity of 4.348 ng cm-2, a relative error of less than ± 1.5% and a relative standard deviation of 0.745 – 1.002% depending on the paracetamol concentration. The proposed method was statistically applied to the determination of paracetamol in pharmaceutical preparations. The proposed method has been statistically evaluated with British Pharmacopeia method and no statistical difference between methods was found at the 95% confidence level.