A sensitive colorimetric method for formaldehyde

✍ Scribed by Joseph Chrastil; John T. Wilson

• Publisher: Elsevier Science
• Year: 1975
• Tongue: English
• Weight: 285 KB
• Volume: 63
• Category: Article
• ISSN: 0003-2697
• DOI: 10.1016/0003-2697(75)90205-5

✦ Synopsis

Formaldehyde reacts with tryptophan in the presence of sulfuric acid and iron, nickel, or cobalt and gives a violet color with absorption maximum at 575 nm. Nanomoles of formaldehyde can be estimated spectrophotometrically by using this reaction which is also very specific. Other aminoacids. sugars and related compounds. higher aldehydes. and heavy metals do not react. 3-Substituted indoles give similar colors of less intensity. The tryptophan reaction can be used to measure formaldehyde formed from biochemical reactions using fractions of liver and other tissues.