Determination of Trace Formaldehyde by Catalytic-Kinetic Spectrophotometry with Xylenol Orange-Potassium Bromate System

A catalytic-kinetic spectrophotometric method has been used for the determination of trace formaldehyde.In sulfuric acid medium,potassium bromate could oxidize and decolorize the xylenol orange under the catalysis of formaldehyde,and the extent of decolorization reaction was proportional to the content of formaldehyde under the maximum absorption wavelength of 435 nm.The reaction was allowed to run for 10 min in 50 ℃ water bath,and the content of formaldehyde had a linear relationship in the range of 0~20 μg/mL.The method has been used in the determination of trace formaldehyde in waste water with satisfactory results.