A Sensitive spectrophotometric method for the determination of microamount of paracetamol is described, based on the oxidation of the drug by Fe(III) in the presence of ferrozine, whereby reduced Fe(II) reacts to build a ferrozine complex. The latter exhibits an absorption maximum at 562 nm with an apparent molar absorptivity of 2.81 x 104 L mol-1 cm-1 and a Sandell sensitivity of 5.4 ng cm-2. The optimum concentration range is 0.1 – 8.0 µg mL-1 of paracetamol. For more accurate results, Ringbom optimum concentration range is 0.25 – 7.50 µg mL-1. Statistical analysis indicated that there was no significant differenve between the results obtained by the proposed method and those of the British Pharmacopoeia method> the method was successful applied to the determination of paracetamol in some pharmaceutical formulations.

Quim. Anal., 19, 135–138 (2000).