Spectrophotometric determination of bromate in flour with naphthol green B

A new spectrophotometric method for the determination of trace potassium bromate in food was developed.In the medium of hydrochloride solution,the colour of naphthol green B changed by the oxidation of potassium bromate.The degree of color changing was proportional to the concentration of potassium bromate.The maximum absorption wavelength located at 415 nm with the apparent molar absorptivity of 5.5×104 L/mol· cm.Beer's law was obeyed from 0 to 14 μg of potassium bromate per 10 mL of solution.The method was used in the determinetion of bromate in flour with satisfactory results.