Assay of Retinol and α-tocopherol involving Ce(IV)-Ce(lll) Redox Couple Spectrophotometrically

Abstract

The present procedure aims to develop an affordable, prompt, and consistent spectrophotometric approach for the assay of Retinol and α-tocopherol in pharmaceutical formulations and distinct edibles. The present procedure based upon the reduction of Ce(IV) into Ce(lll) by the working vitamins retinol and α-tocopherol, the reduced Ce(Ill) formed a blue colored complex with reagenl arsenazo(III) in between the range of pH 3.0-3.3. The optimization of analytical variables was done carefully. The maximum absorption obtained at 648 nm with molar absorptivity 1.5X10⁴ L mol⁻¹ cm⁻¹ and 0.75x 10⁴: L moi⁻¹ cm⁻¹ for Retinol and α-tocopherol respectively. Beer’s law is obeyed within the range of concentrations 0.5-6.0 µg mL⁻¹ for Retinol and 0.4-25.0 µg mL⁻¹ for α-tocopherol. The limit of detection (LOD) was 0.3 µg mL⁻¹ for Retinol and 0.1 µg mL⁻¹ for α-tocopherol and the limit of quantification (LOQ) was 0.9 µg mL⁻¹ for Retinol and 0.3 µg mL⁻¹ for α-tocopherol. The decision limit (CCα) was 0.8 µg kg⁻¹ and 5.2 µg kg⁻¹ and the detection capability (CCα) values were 1.4 µg kg⁻¹ and 9.0 µg kg⁻¹ for Retinol and α-tocopherol respectively. Distinct Edibles were qualified using the proposed method, and the results obtained are in good agreement with the existing methods.