Diazotised anthranilic acid as a reagent for the spectrophotometric determination of ethyl acetoacetate in aqueous solution

Abstract

A sensitive colour reaction for the determination of ethyl acetoacetate in aqueous solution is described. It relies on the reaction of the determinand with diazotised anthranilic acid in the presence of hydrogen carbonate. An intensely colured water-soluble compound is rapidly formed for which a maximum absorbance occurred at 315 nm. Beer's law was obeyed between 10 and 200 µg of ethyl acetoacetate per 25 ml final volume (i.e., 0.4–8 p.p.m.) and a molar absorptivity of 2.59 × 10⁴ l mol^–1 cm^–1 was found. A relative error of +2.2 to –0.8% and a relative standard deviation of 2.4–0.2%, depending on the concentration level, were also observed. Interference due to foreign organic compounds has also been examined.