| SYNONYMS | FOOD GREEN S* C. I. FOOD GREEN 4 * BRILLIANT GREEN BS |
| DEFINITION | Food Green S consists essentially of sodium N-[4-(dimethylamino)phenyl (2-hydroxy-3,6-disulfo-1-naphthalenyl) methylene]-2,5-cyclohexadien-1-ylidene-N-methylmethanaminium and subsidary colouring metters together with sodium chloride and/or sodium sulfate as the principal uncoloured compounds. |
| Food Green S is described as the sodium salt. The calcium and the potassium salt are also permitted. | |
| CLASS | Triarylmethane |
| COLOUR INDEX NO. | 44090 |
| EEC NUMBER | E-142 |
| EINECS | 221-409-2 |
| CHEMICAL NAMES | Sodium N-[4-[[4-(dimethylamino)phenyl] (2-hydroxy-3,6-disulfo-1-naphthalenyl) -methylene]-2,5-cyclohexadien-1-ylidene-N-methylmethanaminium; |
| Sodium 5-[4-dimethylamino- alpha -(4-dimethyliminocyclohexa-2,5- | |
| dienylidene)benzyl]-6-hydroxy-7-sulfonato-naphthalene-2-sulfonate (alternative chemical name) | |
| CHEMICAL FORMULA | C27H25N2NaO7S2 |
| MOLECULAR WEIGHT | 576.63 |
| ASSAY | Content not less than 80% total colouring matters, calculated as the sodium salt |
| E 1% 1cm 1 720 at ca 632 nm in aqueous solution | |
| DESCRIPTION | Dark-blue or Dark Green powder |
| IDENTIFICATION | |
| a. Spectrometry | Maximum in water at ca 632 nm |
| b. Blue or Green solution in water | |
| PURITY | Not more than 0.2% |
| Water Insoluble matter | |
| Subsidiary colouring matters | Not more than 1.0% |
| Organic compounds other than colouring matters | [4,4'-bis(dimethylamino-benzhydryl alcohol] - Not more than 0.1% |
| [4,4'-bis(dimethylamino-benzophenone] - Not more than 0.1% | |
| [3-hydroxynaphthalene-2,7-disulfonic acid] - Not more than 0.2% | |
| Unsulfonated primary aromatic amines | Not more than 0.01% (Calculated as aniline) |
| Ether extractable matter | Not more than 0.2% under neutral conditions |
| Arsenic | Not more than 3 mg/kg. |
| Lead | Not more than 10 mg/kg. |
| Mercury | Not more than 1 mg/kg. |
| Cadmium | Not more than 1 mg/kg. |
| Heavy metals | Not more than 40 mg/kg |
| (as Pb) |
