Bromcresolgrønn

Bromcresolgrønn, also known as bromcresol purple, is a synthetic dye used primarily as a pH indicator. It is a water-soluble compound with the chemical formula C27H28Br2N3O5S. The dye is a mixture of two tautomers, bromcresol red and bromcresol blue, which are structurally similar but differ in their color and pH sensitivity.

Bromcresolgrønn is commonly used in laboratory settings to determine the pH of a solution. It changes color at different pH levels, providing a visual indication of the acidity or alkalinity of the solution. The dye turns yellow at a pH of 3.8, red at a pH of 5.2, purple at a pH of 6.8, and blue at a pH of 8.2. This range of color changes makes it a useful tool for pH measurements in various scientific and industrial applications.

The dye is also used in the food industry as a color additive, particularly in the production of candies and other confections. It is approved for use in the European Union and the United States, where it is listed as E133 and FD&C Blue No. 2, respectively. Bromcresolgrønn is generally recognized as safe for use in food, but its use is subject to regulations and labeling requirements to ensure consumer safety.

Despite its widespread use, bromcresolgrønn has been the subject of some controversy due to potential health concerns. Some studies have suggested that the dye may have toxic effects, particularly on the liver and kidneys, although these findings are not universally accepted. As a result, the use of bromcresolgrønn in food is closely monitored, and its safety is continually evaluated by regulatory authorities.