Studies on Catalytic Kinetic Spectrophotometric Determination of Trace Formaldehyde

A catalytic kinetic spectrophotometric method for the determination of trace formaldehyde was proposed.The method is based on the catalysis of trace formaldehyde to discoloring reaction of methyl orange oxidized by potassium bromate in the solution of dilute H_2SO_4.Under the selected conditions,the apparent molar absorption coefficient is 1.18×10~5 L·mol~(-1)·cm~(-1),and the linear range of 0~0.16 mg/L is obtained for formaldehyde with a detection limit of 2.8 μg/L.The method was applied to the determination of trace formaldehyde in drink,waste water and air sample with satisfactory results.The RSD was less than 5%(n=5),and recovery was between 93%~106%.