In this application, the quantitative analysis of formaldehyde was successfully executed using the LAMBDA 265 UV/Vis spectrophotometer and Merck Spectroquant formaldehyde cell test kit. Principle Formaldehyde reacts with chromotropic acid in sulphuric solution to form a violet dye which can be detected photometrically at 565 nm. The formaldehyde cell test kit is appropriate for the concentration range of 0.10 to 8.00 mg/L formaldehyde allowing the concentration of formaldehyde in a water sample to be determined without the use of a calibration curve by multiplying the measured absorbance at 565 nm by a known factor.