CHOCOLATE BROWN |
|
| SYNONYMS | CHOCOLATE BROWN * C. I. FOOD BROWN 3 * FOOD BROWN 2* BROWN HT |
| DEFINITION | Chocolate Brown consists essentially of disodium
4,4'-(2,4-dihydroxy-5-hydroxymethyl-1,3-phenylene bisazo) di
(naphthalene-l-sulfonate) and subsidiary colouring
matters together with sodium chloride and/or sulfate as the
principal uncoloured components. Chocolate Brown is described as the sodium salt. The calcium and the potassium salt are also permitted. |
| CLASS | Bisazo |
| COLOUR INDEX NO. | 20285 |
| EEC NUMBER | E-155 |
| EINECS | 224-924-0 |
| CHEMICAL NAMES | Disodium 4,4'-(2,4-dihydroxy-5-hydroxymethyl-1,3-phenylene bisazo) di (naphthalene-l-sulfonate) |
| CHEMICAL FORMULA | C17H18N4Na2O9S2 |
| MOLECULAR WEIGHT | 652.57 |
| ASSAY | Content not less than 70% total colouring
matters, calculated as the sodium salt; E 1% 1cm 403 at ca 460 nm in aqueous solution at pH7 |
| DESCRIPTION | Reddish-brown powder |
| IDENTIFICATION | |
| a. Spectrometry b. Brown solution in water |
Maximum in water of pH 7 at ca 460 nm |
| PURITY Water Insoluble matter |
Not more than 0.2% |
| Subsidiary colouring matters | Not more than 10% (TLC method) |
| Organic compounds other than colouring matters | [4-aminonaphthalene-l-sulfonic acid] - Not more than 0.7% |
| Unsulfonated primary aromatic amines | Not more than 0.01% (Calculated as aniline) |
| Ether extractable matter | Not more than 0.2% in a solution of pH7 |
| 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 (as Pb) | Not more than 40 mg/kg. |