Simultaneous Spectrophotometric Determination of Ponceau-S and Erythrosine in Pharmaceutical, Cosmetic and Food Samples by Using Mean Centering of Ratio Spectra Method

Abstract

A new micelle-mediated extraction method for ultra-trace quantities of ponceau-s and erythrosine as a prior step to their simultaneous Spectrophotometric determination has been developed. The mean centering (MC) of ratio spectra method is based on the difference in the absorption spectra for the products of the reaction of ponceau-s and erythrosine with Fe (III) in the presence of Sodium Lauryal Sulphate (SLS) micellar media at pH 5.5. The method allows rapid and accurate determination of ponceau-s and erythrosine. The conditions were optimized for analytical characteristics of the method (e.g. limit of detection, linear range) were obtained. Beer`s law was obeyed in the concentration range of 0.175-6.15 µg mL^-1 of ponceau-s and 0.304 – 4.56 µg mL^-1 of erythrosine. The proposed method has successfully been applied for simultaneous determination of ponceau-s and erythrosine in pharmaceutical and food samples.