The 4-aminoantipyrine Method Revisited: Determination of Trace Phenols by Micellar Assisted Preconcentration

The traditional method for phenol analysis based on the oxidizing coupling of 4-aminoantipyrine (4-APP) with phenol in alkaline solution is re-evaluated in this study in combination with micellar assisted preconcentration (cloud point extraction). The method employs the conventional reaction pathway while extraction is facilitated by surfactant based precipitation, during which the nonpolar derivative of 4-AAP-phenol is entrapped in the micelles and concentrated into a surfactant-rich phase. The latter is the re-solubilized and the complex is quantified spectrophotometrically in the presence of a surfactant. Compared to the traditional method the modification proposed offers certain analytical advantages like massive analysis of many samples, lower detection limits and shorter time of analysis. The method was applied in various samples of different origin with satisfactory results.