Nitrazine Yellow is a synthetic pH-sensitive azo dye with the chemical formula C₁₆H₈N₄Na₂O₁₁S₂. It is also known as Phenaphthazine or Nitrazol Yellow. The compound is the disodium salt of a sulfonated azo dye and generally occurs as a yellow to dark-yellow powder or crystalline material. Its sulfonate groups contribute to its water solubility, while its azo structure gives it characteristic color properties. Nitrazine Yellow changes from yellow to blue over approximately pH 6.0–7.0, making it a useful indicator for detecting changes in acidity and alkalinity.
CAS No.: 5423-07-4
Synonyms: Nitrazine Paper; Nitrazol Yellow; Phenaphthazine; Delta Paper.
| Physical Properties | |
| Chemical formula | C16H8N4Na2O11S2 |
| IUPAC Name | Phenaphthazine, (3E)-3-[(2,4-Dinitrophenyl)hydrazono] -4-oxonaphthalene-2,7-disulphonic acid |
| Molecular weight | 544.4 g/mol |
| Appearance | Orange coloured crystalline powder |
| Solubility | Soluble in water |
| Storage | Store at room temperature |
| Chemical Properties | |
| Color | Yellowish to dark yellow |
| Physical State | Solid |
| λmax | 586 nm |
| Ph | 6.0 -7.2 |
| Odor | Odorless |
| Pictograms : |  |
| Hazard Statements : | H228: Flammable solid. H317: May cause an allergic skin reaction. H351: Suspected of causing cancer. |
| Precautionary Statements: | P201: Obtain special instructions before use. P202: Do not handle until all safety precautions have been read and understood. P210: Keep away from heat/sparks/open flames/hot surfaces. – No smoking. P240: Ground/bond container and receiving equipment. P241: Use explosion- proof electrical/ventilating/lighting/ … /equipment P261: Avoid breathing dust/ fume/ gas/ mist/ vapours/ spray. P272: Contaminated work clothing should not be allowed out of the workplace. P280: Wear protective gloves/protective clothing/eye protection/face protection. P281: Use personal protective equipment as required. P302+P352: IF ON SKIN: Wash with plenty of soap and water. P308+P313: IF exposed or concerned: Get medical advice/attention. P333+P313: If skin irritation or rash occurs: Get medical advice/attention. P363: Wash contaminated clothing before reuse. P405: Store locked up. |
Nitrazine Yellow is a synthetic pH-sensitive azo dye with the chemical formula C₁₆H₈N₄Na₂O₁₁S₂. It is also known as Phenaphthazine or Nitrazol Yellow. The compound is the disodium salt of a sulfonated azo dye and generally occurs as a yellow to dark-yellow powder or crystalline material. Its sulfonate groups contribute to its water solubility, while its azo structure gives it characteristic color properties. Nitrazine Yellow changes from yellow to blue over approximately pH 6.0–7.0, making it a useful indicator for detecting changes in acidity and alkalinity.
CAS No.: 5423-07-4
Synonyms: Nitrazine Paper; Nitrazol Yellow; Phenaphthazine; Delta Paper.
| Physical Properties | |
| Chemical formula | C16H8N4Na2O11S2 |
| IUPAC Name | Phenaphthazine, (3E)-3-[(2,4-Dinitrophenyl)hydrazono] -4-oxonaphthalene-2,7-disulphonic acid |
| Molecular weight | 544.4 g/mol |
| Appearance | Orange coloured crystalline powder |
| Solubility | Soluble in water |
| Storage | Store at room temperature |
| Chemical Properties | |
| Color | Yellowish to dark yellow |
| Physical State | Solid |
| λmax | 586 nm |
| Ph | 6.0 -7.2 |
| Odor | Odorless |
| Pictograms : | |
| Hazard Statements : | H228: Flammable solid. H317: May cause an allergic skin reaction. H351: Suspected of causing cancer. |
| Precautionary Statements: | P201: Obtain special instructions before use. P202: Do not handle until all safety precautions have been read and understood. P210: Keep away from heat/sparks/open flames/hot surfaces. – No smoking. P240: Ground/bond container and receiving equipment. P241: Use explosion- proof electrical/ventilating/lighting/ … /equipment P261: Avoid breathing dust/ fume/ gas/ mist/ vapours/ spray. P272: Contaminated work clothing should not be allowed out of the workplace. P280: Wear protective gloves/protective clothing/eye protection/face protection. P281: Use personal protective equipment as required. P302+P352: IF ON SKIN: Wash with plenty of soap and water. P308+P313: IF exposed or concerned: Get medical advice/attention. P333+P313: If skin irritation or rash occurs: Get medical advice/attention. P363: Wash contaminated clothing before reuse. P405: Store locked up. |
Nitrazine Yellow is mainly used as a pH indicator. It is also used in nitrazine paper, biochemical assays, microscopy, and selected analytical research.
Nitrazine Yellow is the indicator dye used in nitrazine paper. The paper is impregnated with the dye and changes color in response to pH.
