Determination of Trace Formaldehyde by Catalytic Kinetic Spectrophotometry of Potassium Bromate-Bromocresol Green

In sulfuric acid medium,formaldehyde had significant catalytic effect on potassium bromate oxidation of bromocresol green solution fade.The fade degree was proportional to formaldehyde content.Based on that,a new catalytic kinetic spectrophotometry method was set up to determine trace formaldehyde.The maximum absorption wavelength was at 445nm,the reaction time was 22 minutes in 50℃ water bath.The formaldehyde contents had a good linear relationship in range of 0~14.0 μg/25mL.The method had been used for the determination of trace formaldehyde in laboratory wastewater with satisfactory results.