Scientists say that they have develop a 'litmus paper' for analyzing odor chemistry.
Metalloporphyrins are related to the natural pigments found in red blood and green plants. By watching the color change in the presence of a specific aroma, scientists could determine the aroma's source, or what it smelled like. Litmus paper changes color to reflect the acidity or alkalinity of a substance. Suslick and Neal Rakow, another Illinois chemist, described the invention in Thursday's issue of the journal Nature. They then exposed the swatch to a variety of vapors.