Assay of Retinol and α‐tocopherol involving Ce(IV)‐Ce(III) 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(III) by the working vitamins retinol and α‐tocopherol, the reduced Ce(III) formed a blue colored complex with reagent 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 1.5×10⁴ L mol^‐1cm^‐1 and 0.75×10⁴ L mol^‐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^‐1for 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 (CCβ) values were 1.4 μg kg^‐1 and 9.0 μg kg^‐1 for Retinol and α‐tocopherol respectively. Distinct Edibles were quantified using the proposed method, and the results obtained are in good agreement with the existing methods.