Complaint
| OTASSIUM METABISULFITE Basic information | |
| Product Name: | POTASSIUM METABISULFITE |
| CAS: | 16731-55-8 |
| MF: | K2O5S2 |
| MW: | 222.32 |
| EINECS: | 240-795-3 |
| POTASSIUM METABISULFITE Chemical Properties | |
| Melting point | 190°C |
| density | 2.34 g/cm3 |
| vapor density | 2.3 (vs air) |
| storage temp. | Store at +5°C to +30°C. |
| solubility | H2O: 0.1 M at 20 °C, clear, colorless |
| form | Powder/Solid |
| Specific Gravity | 2.3 |
| color | White to slightly yellow |
| Odor | Odorless |
| PH | 2.5-4.5 (25ºC, 0.1M in H2O) |
| PH Range | 3-4.5 at 22.2 g/l at 25 °C |
| Water Solubility | Soluble in water. Insoluble in ethanol. |
| λmax | 267nm(H2O)(lit.) |
| Sensitive | Air Sensitive |
| Decomposition | 150°C |
| Merck | 147,645 |
| EPA Substance Registry System | Disulfurous acid, potassium salt (1:2) (16731-55-8) |
Food Grade Potassium Metabisulfite
Food Grade Potassium Metabisulfite use: used in the preparation of photographic developer.Also used as food bleach, preservative, antioxidant;Preservative of wine and fruit juice;Beer clarifiers, fresh fruits and vegetables, meat, grapes preservation, can also be used on cyanide - free silver plating.
Technical indicators:
Test item | Unit | Specification | Test method |
K2S2O5 | g/100g | ≥97.2 | Acc.Fcc IV p.322 |
SO2 | g/100g | ≥56.0 | To calculate |
K2S2O3 | g/100g | ≤ 0.1 | ISO 3629-1996(E) |
Na | g/100g | ≤ 2 | AAS |
Cl | g/kg | ≤0.5 | IC |
pH(10% solution) | - | 3.8-4.8 | RCA/Q-S-066 |
Pb | mg/kg | ≤10 | AAS |
As | mg/kg | ≤1 | AAS |
Cu | mg/kg | ≤1 | ICP-AES |
Fe | mg/kg | ≤5 | ICP-AES |
Hg | mg/kg | ≤0.1 | AAS(cold vapour) |
Pb | mg/kg | ≤1 | ICP-AES |
Se | mg/kg | ≤1 | AAS |
Zn | mg/kg | ≤1 | ICP-AES |
K2SO3 +K2SO4 | mg/kg | allowance | To calculate |
Reagent Grade Potassium Metabisulfite:
Standard: Reagent grade overweight potassium sulfite
Reagent grade potassium metabisulfite is a chemical substance with the molecular formula K2S2O5.It is the most commonly used bactericidal and antioxidant excipient in Europe and America, and its SO2 content is 57%.SO2 has the function of anti-oxidation, sterilization and promoting the growth of beneficial microorganisms. In the brewing process of wine, SO2ur dioxide has become an important means to ensure the quality of wine irreplaceable. It has been in the history of wine making for more than 100 years and has been allowed to be added into wine by law.
Technical indicators:
Test item | Unit | Analysis of pure | Chemically pure |
content (K2S2O5)≥ | % | 95.0 | 94.0 |
Clarity test |
| qualified | qualified |
Water insoluble substance ≤ | % | 0.005 | 0.02 |
chloride (Cl)≤ | % | 0.005 | 0.01 |
Pb ≤ | % | 0.001 | 0.002 |
Fe ≤ | % | 0.0005 | 0.002 |
(As) ≤ | % | 0.0001 | 0.0003 |
Reagent grade pyrosulfite purpose: Used as analytical reagent.
Photographic Grade Potassium Metabisulfite:
Standard: Photographic grade potassium metabisulfite (ISO 3629-2000)
Properties of photographic potassium metabisulfite: colorless crystal or white crystalline powder.Relative density 2.34.Melting point 150-190ºC (decomposition).It has a smell of SO2 and is soluble in water. Its aqueous solution is acidic and insoluble in ethanol. is emitted from an acidic solution and oxidized to sulfate in the air.
Technical indicators:
| Test item | Unit | Specification | Test method |
K2S2O5 | g/100g | ≥97.2 | ANSI PH 4277-1980 |
SO2 | g/100g | ≥56.0 | To calculate |
Aqueous solution properties | - | qualified | ISO 3629-1976(E) |
K2S2O3 | g/100g | ≤ 0.07 | ISO 3629-1976(E) |
pH(5% solution) | - | 3.8-4.6 | ISO 3629-1976(E) |
Pb | mg/kg | ≤10 | ICP-AES |
Fe | mg/kg | ≤5 | ICP-AES |
And NH3/AgNO3 solution | - | qualified | ISO 3629-1976(E) |
K2SO3 +K2SO4 | mg/kg | allowance | To calculate |
Photographic grade potassium metabisulfite use: used in the preparation of photographic developer.
