What is luminol composed of?
The “central” chemical in this reaction is luminol (C8H7O3N3), a powdery compound made up of nitrogen, hydrogen, oxygen and carbon. Criminalists mix the luminol powder with a liquid containing hydrogen peroxide (H2O2), a hydroxide (OH-) and other chemicals, and pour the liquid into a spray bottle.
How does Luminol chemiluminescence work?
Luminol is an organic compound which, when oxidized, emits light — a phenomenon known as chemiluminescence. When the molecule 2 is formed, it is in an excited (higher energy) electronic state, and sheds its “extra” energy by emitting a photon of light (hn), allowing the molecule to go to its ground state form (3).
What is the chemical equation for chemiluminescence?
The chemiluminescence reaction between nitrogen monoxide and ozone is formulated as: N O + O 3 → N O 2 * + O 2 NO 2 * → N O 2 + h v . NO2 refers to the excited nitrogen oxide molecule. These molecules can decay by emission of light of wavelengths longer than 600 nm.
How is luminol manufactured?
Reduction of the nitro group to an amino group with sodium dithionite (Na2S2O4), via a transient hydroxylamine intermediate, produces luminol.
What color does luminol glow in the presence of blood?
blue glow
After spraying luminol, the latent blood traces emit a blue glow.
How is luminol used?
Forensic investigators use luminol to detect trace amounts of blood at crime scenes, as it reacts with the iron in hemoglobin. When luminol is sprayed evenly across an area, trace amounts of an activating oxidant make the luminol emit a blue glow that can be seen in a darkened room.
What is chemiluminescence with example?
Chemiluminescence is defined by the release of light from a chemical reaction. This process occurs naturally in fireflies and several types of sea creatures such as jellyfish, in these cases it is also called bioluminescence. Glowsticks, the vibrant party favors, are also a form of chemiluminescence.
Who discovered luminol?
Walter Specht
In 1937 Walter Specht at the University Institute for Legal Medicine in Jena, Germany developed Luminol as a test for blood. The test is so sensitive that it can detect blood in the parts per million range – even if it’s years old!
Does luminol destroy DNA?
Luminol has been widely used in the field of crime scene investigations to detect latent blood; however, luminol has the tendency to destroy DNA evidence. Fluorescein, an alternative to luminol for detecting latent blood at a crime scene, does not destroy DNA evidence.
Is luminol a chemiluminescent?
Luminol is a well-known chemiluminescent compound that is used in forensics since it glows blue on reacting with blood. It is also used by researchers to detect traces of hydrogen peroxide, proteins and DNA.