Sodium pyrophosphate
1, Structure and properties of sodium pyrophosphate
Sodium phosphate can be divided into aqueous sodium pyrophosphate and anhydrous odium pyrophosphate according to the existence in sodium phosphate molecule or not. Aqueous sodium pyrophosphate is also called sodium pyrophosphate crystal , molecular formula : Na4P2O7·10H2O , molecular weight : 46.06 , colorless transparent or white crystal or crystalline powder, relative density : 1.824 , soluble in ethanol. Aqueous solution appears basic(in 1% aqueous solution, PH is 10.0-10.2). Anhydrous odium pyrophosphate : molecular formula : Na4P2O7 , molecular weight : 265.90 , white lumpy solid or white powder, soluble in water, insoluble in alcohol, relative density : 2.45 , melting point 890 °C .
2, Use
Technical grade is used in detergent auxiliary, cyanideless electroplating; used as food quality improver in food industry, PH regulator , metallic ion chelating agent; also used in producing cream etc..
3, Quality standard of food additive sodium pyrophosphate(GTB8848-1988)
Index name |
|
| Main content(based on dry basis) % ≥ |
96.5 |
| Insoluble substance in water % ≤ |
96.5 |
| PH value(1% solution) |
9.9-10.7 |
| Orthophosphate % ≤ |
Qualified |
| Arsenic content (AS) % ≤ |
0.0003 |
| Heavy metal (Pb) % ≤ |
0.001 |
| Fluoride (F) % ≤ |
0.005 |
| Loss on ignition % ≤ |
0.5 |
| Appearance |
White powder |
|
