Spectrophotometric determination of formaldehyde based on the telomerization reaction of tryptamine

A simple and sensitive spectrophotometric method for the determination of formaldehyde FA in different samples using tryptamine TA in a sulfuric acid medium was developed. A trace amount of sodium nitrite was added to enhance the production of a red violet colored product exhibiting an absorbance maximum at 558 nm. Beer’s Law is obeyed for 0.80–23.00 μg mL−1 FA (r = 0.999), the recoveries are within the range of 96.25–100.66%, with percent relative standard deviations ranging from 1.02% to 2.73%. No interference was detected from commonly existing contaminates in the liquid samples e.g. phenol, aminoacids, sugars and related compounds. The method was applied successfully for the determination of formaldehyde in various environmental samples, such as rain water, wood products, and total cigarette smoke.