Sensitive reaction rate method for the determination of low levels of formaldehyde with photometric detection

A simple and rapid method is proposed for the determination of ultra trace amounts of formaldehyde. It is based on the catalytic effect of formaldehyde on the oxidation of Brilliant cresyl blue by bromate. The reaction is monitored photometrically by measuring the decrease in absorbance of the dye. Formaldehyde in the range of 0.005-2.300 mu g/mL can be determined with a limit of detection of 0.003 mu g/mL. The relative standard deviation for ten replicate measurements of 1.5 mu g/mL formaldehyde is 0.1%. The method was used for the determination of formaldehyde in real samples with satisfactory results.