A colorimetric method for the micro determination of 2-phenylphenol

Abstract

A colour reaction produced with the fungicide 2-phenylphenol is described. 2-Phenylphenol, its esters and sodium 2-phenylphenate give a pink colour with concentrated sulphuric acid and traces of formaldehyde and iron(III), which is specific for 2-phenylphenol. With 5 ml of reagents, 1 µg of these compounds produces colours that are discernible visually. In fixed conditions the reaction conforms to the Beer-Lambert law for up to 16 µg of 2-phenylphenol per 5 ml of reagents. A simple and rapid method has been evolved for its determination in disinfectant solutions containing sodium 2-phenylphenate, and in paper wrappers impregnated with 2-phenylphenol, its esters or its sodium salt. Recovery varies from 94·1 to 105·0 per cent.; the deviations remain within the limits of experimental error.