Luminol
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Luminol is a chemical used by forensic investigators to detect blood.
- formula:<math>C_8H_7N_3O_2<math>
- CAS number: 521-31-3
Synonyms
- 5-Amino-2,3-dihydro-1,4-phthalazinedione [521-31-3]
- o-aminophthaloyl hydrazide
- o-aminophthalyl hydrazide
- 3-Aminophthalhydrazide
- 3-aminophthalic hydrazide
- Luminol
Use by Crime Scene Investigators
Theory
Luminol is used by investigators to locate blood, even if it has been cleaned or removed. Using its natural property of chemiluminescence, it luminesces upon reacting with hydrogen peroxide. Iron in haemoglobin, a pigment present in blood, is provided as a catalyst in the luminescence. The glow lasts for about 30 seconds and is blue.
Drawbacks
Nevertheless, Luminol has drawbacks that can keep it from detecting just blood that has been shed in a crime:
- Luminol also fluoresces in the presence of copper or an alloy of copper, certain bleaches and horseradish.
- Luminol will also detect the small amounts of blood present in urine and it can be distorted if animal blood was present in the room that is being tested.
- Luminol presence may prevent other tests to be performed on a piece of evidence.
- Luminol is listed as possible carcinogen but has not yet been proven as such.
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Other Uses
- Medical: Used to conduct biochemical assays
- Amusement: Glowing light sticks
- Education: Getting young people interested in science
External links
- Synthesis of Luminol (http://cas.bellarmine.edu/chem117a/lab/luminol.htm)
- Technical note about Hemaglow™ (http://www.redwop.com/technotes.asp?ID=118)
- HowStuffWorks "How Luminol Works" (http://people.howstuffworks.com/luminol.htm)de:Luminol