An Australian research team has managed to improve the so-called Egyptian blue powder and enhance its efficacy to help detect criminals’ fingerprints on surfaces and floors.
The pigment, scientifically known as the Egyptian blue had been found in some types of varnish used in painting statues, coffins, and walls in ancient Pharaonic tombs.
Decades ago, researchers managed to determine the chemicals that compose this powder, which allowed using it in different applications such as fingerprints detection.
In a study published in the Dyes and Pigments journal in May, 2016, a British research team found that “dusting the Egyptian blue powder on surfaces can improve the detection of fingerprints.”
The researchers used a camera and a filter sensitive to near-infrared rays to digitally photograph the surface under a white light in order to reveal fingerprint traces, if found. When exposed to light, the pigment emits rays that help reveal what may be invisible to the naked eye.
According to a recent study that will be published in May by the ASCLD’s Forensic Chemistry journal, this Egyptian blue pigment can be developed to boost the brightness of the infrared light, which will help reveal challenging invisible fingerprints with simple low-cost photography equipment.
According to a report released on Monday by the journal’s website, “coating the Egyptian blue powder with cetrimonium bromide molecules could enhance the contrast that reveals the fingerprints traces.”
Dr. Khalid Mohammadi, a chemistry professor at the South Valley University, Egypt, says that the added material makes the pigment more responsive to oils, and thus, improves its efficacy in revealing fingerprints.
A human fingerprint contains sweat and oils secreted by the skin, and the added cetrimonium bromide molecules would improve the powder’s reaction with these oils when brushed on the surfaces, which will enhance the revelation of fingerprints, Mohammadi said.