Rapid Spectrophotometric Determination of Thallium with Mepazine Hydrochloride

Abstract

Mepazine hydrochloride reacts with thallium(III) at room temperature in phosphoric acid medium to give and orange-red species with an absorption maximum at 512 nm. The reaction obeys Beer’s law over the concentration range 0.1-13.0 μg/ml of thallium(III) with an effective spectrophotometric range of 1.8-11.0 μg/ml. The molar absorptivity is 1.60 x 10⁴ dm³ mol^-1 cm^-1. The efficacy of the method is shown by the successful determination of thallium in synthetic thallium alloys.