Determination of Phenol in Water by 4-Aminoantipyrine Spectrometry Using Peroxodisulfate as Oxidant

We studied using an ammonium peroxodisulfate as the oxidizing reagent instead of potassium hexacyanoferrate(III) on the 4-aminoantipyrine spectrometry for the determination of phenol. Suitable color development was obtained by the addition of 1 - 5 mL of ammonium peroxodisulfate solution (pH 10, 220 mmol/L) and 2 mL of 4-aminoantipyrine solution (98 mmol/L) to a 100 mL sample solution of pH 10 buffered with an ammonium chloride - ammonia solution (9.8 mol/L). The proposed procedure was applied to methyl benzoate extraction for determining small amounts of phenol in water. Results obtained by the proposed method were in agreement with that by the JIS method.