Acta Pharm. 52 (2002) 45-51

Use of arsenazo III for determination of vitamin C involving Ce(IV)-Ce(III) redox couple

S. P. ARYA,^* PREETI JAIN and MEENAKSHI MAHAJAN

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Department of Chemistry, Kurukshetra University, Kurukshetra - 136 119, Haryana, India

A method based on Ce(III)-arsenazo III complex formation for determination of vitamin C is described. The absorbance of the blue complex is measured at 650 nm and the system obeys Beer's law up to 2.3 x 10^-5 mol L^-1, with molar absorbtivity of 2.95 x 10⁴ L mol^-1 cm^-1 ant the coefficient of correlation of 0.9925. Limit of detection is 5.6 x 10^-7 mol L^-1 and relative standard deviation is 1.9%. Interference studies of various substances, including amino acids, vitamins, organic acids and sweeteners, were carried out and commercial pharmaceuticals were analysed by the proposed method.

Keywords: vitamin C determination, arsenazo III, Ce(IV)-Ce(III) redox couple