Indigo carmine is an organic salt obtained from indigo via aromatic sulfonation, making it water-soluble. This dye produces a blue color and is commonly recognized as Blue No. 2 or E132 in the U.S. and EU. It also acts as a pH and redox indicator, exhibiting a color change based on pH levels. It is used in diverse industries, including food, cosmetics, and pharmaceuticals.
CAS No.:860-22-0
Synonyms: Indigotine; Indigotindisulfonate sodium; E132; CI natural blue II; FD&C Blue No.2; Sicovit Indigotin 85; Food Blue 1; C.I. Acid Blue 74; Brilliant Indigo
| Physical Properties | |
| Chemical formula | C16H8N2Na2O8S2 |
| IUPAC Name | Disodium[2(2′)E]-3,3′-dioxo-1,1′,3,3′-tetrahydro[2,2′-biindolylidene]- 5,5′-disulfonate |
| Molecular weight | 466.4 g/mol |
| Solubility | Water ( 10 g/L at 25°C ), Methanol(0.01 g/10 mL) |
| Flash point | >250°C |
| Density | 1.2 g/cm³ |
| Chemical Properties | |
| Color | Deep Blue, Purplish-blue |
| State | Powder, granules |
| Melting point | >300 °C (572 °F) |
| λmax | 289 nm |
| Pictograms : |  |
| Hazard Statements : | H317: May cause an allergic skin reaction |
| Precautionary statements : | P280: Wear protective gloves/eye protection |
Indigo carmine is an organic salt obtained from indigo via aromatic sulfonation, making it water-soluble. This dye produces a blue color and is commonly recognized as Blue No. 2 or E132 in the U.S. and EU. It also acts as a pH and redox indicator, exhibiting a color change based on pH levels. It is used in diverse industries, including food, cosmetics, and pharmaceuticals.
CAS No.:860-22-0
Synonyms: Indigotine; Indigotindisulfonate sodium; E132; CI natural blue II; FD&C Blue No.2; Sicovit Indigotin 85; Food Blue 1; C.I. Acid Blue 74; Brilliant Indigo
| Physical Properties | |
| Chemical formula | C16H8N2Na2O8S2 |
| IUPAC Name | Disodium[2(2′)E]-3,3′-dioxo-1,1′,3,3′-tetrahydro[2,2′-biindolylidene]- 5,5′-disulfonate |
| Molecular weight | 466.4 g/mol |
| Solubility | Water ( 10 g/L at 25°C ), Methanol(0.01 g/10 mL) |
| Flash point | >250°C |
| Density | 1.2 g/cm³ |
| Chemical Properties | |
| Color | Deep Blue, Purplish-blue |
| State | Powder, granules |
| Melting point | >300 °C (572 °F) |
| λmax | 289 nm |
| Pictograms : | |
| Hazard Statements : | H317: May cause an allergic skin reaction |
| Precautionary statements : | P280: Wear protective gloves/eye protection |
Indigo Carmine is produced by sulfonating Indigo dye with sulfuric acid, then neutralizing it with sodium hydroxide. The final product is purified by crystallization.
Indigo Carmine is used as a dye in various applications, including medical procedures (like urinary tract visualization), food coloring, and laboratory staining.
Indigo Carmine is generally used as a dye and has minimal effects when used in controlled amounts. It can cause temporary discoloration in bodily fluids. It’s usually safe but may cause allergic reactions or gastrointestinal discomfort if overexposed.
No, Indigo carmine is a synthetic dye, not a natural food color.
Indigo Carmine can cause temporary fluid discoloration, allergic reactions, and, in some cases, a brief increase in blood pressure and reflex bradycardia under anesthesia.
