Luminol is a versatile chemical that
exhibits chemiluminescence, with a striking blue glow, when mixed with an
appropriate oxidizing agent. It is a white to slightly yellow crystalline solid
that is soluble in most polar organic solvents, but insoluble in water.
This is a five-gram packs
Luminol is used by forensic investigators
to detect trace amounts of blood left at crime scenes as it reacts with iron
found in hemoglobin. It is used by biologists in cellular assays for the
detection of copper, iron, and cyanides, in addition to the detection of
specific proteins by western blot.
For analysis of an area, luminol can be
sprayed evenly across the area, and trace amounts of an activating oxidant will
cause the luminol to emit a blue glow that can be seen in a darkened room. The
glow lasts for about 30 seconds, but the effect can be documented by a long-exposure
photograph. It is important that the spraying be evenly applied to avoid
creating a slanted, or biased impression, such as blood traces appearing to be
more concentrated in areas which received more spray. The intensity of the glow
does not indicate the original amount present, but only the distribution of
trace amounts of substances left in the area.
(Wikipedia)
Mechanism:
Apparatus
1.
A PET bottle
2.
Funnel
3.
400mL beaker
Chemical
1.
Luminol: 0.06g
2.
Sodium carbonate: 1.70g
3.
Sodium bicarbonate: 7.20g
4.
Ammonium carbonate: 0.15g
5.
Cupric sulfate: 0.12g
6.
Aqueous hydrogen peroxide: 35%
1.5mL
7.
Water: 300mL x2
Procedure
Making solution A
1.
Pour 300mL water in a PET
bottle
2.
Place Luminol, Sodium carbonate,
Sodium bicarbonate, Ammonium carbonate and cupric sulfate in the PET bottle and
mix with water thoroughly.
Make Solution B
Add 1.5mL 35% aqueous hydrogen peroxide in 300mL water in a beaker
Start the Reaction
1.
Set up a funnel on the top of
the PET bottle.
2.
Turn off all the light in the
room.
3.
Pour Solution B into the PET
bottle and the reaction starts.
The Blue Light can be seen in a bright room
