Sodium phosphates (E339). Sodium phosphate what is sodium phosphate
Sodium phosphate Na 3 PO 4 is a medium salt of orthophosphoric acid H 3 PO 4 and sodium hydroxide NaOH. Food additive with an E542 index, belongs to the group of emulsifiers, pH regulators and substances against the track.
Synonyms
Sodium orthophosphate, trinitium phosphate, sodium phosphate
Formula
Properties of sodium phosphate
Physical properties
Chemical properties
In aqueous solutions, hydrolyzed by anion:
Na 3 P0 4 + H 2 O \u003d Na 2 HP0 4 + Na0H.
The solution has an alkaline reaction.
When interacting with acids forms acidic salts:
Na 3 P0 4 + HCL \u003d Na 2 HP0 4 + NaCl,
Na 3 P0 4 + H 2 SO 4 \u003d NAH 2 P0 4 + Na 2 SO 4.
Enters the exchange reaction to the formation of insoluble phosphates:
2NA 3 P0 4 + 3CACL 2 \u003d 6NACL + 2CA 3 (P0 4) 2 ↓,
Na 3 P0 4 + ALCL 3 \u003d 3NACL + ALP0 4 ↓,
Na 3 P0 4 + 3AGNO 3 \u003d 6NACL + AG 3 P0 4 ↓.
The latter reaction is a qualitative reaction to soluble alkali metal phosphates and ammonium. When the Silver Nitrate Nitrate solution is added to them, the silver phosphate sediment Ag 3 P0 4 is yellow. And sodium can be determined to staining the flame in yellow.
Obtaining a chemical compound
Laboratory methods for getting
Sodium phosphate is obtained by phosphoric acid interaction with hydroxide or sodium carbonate:
H 3 PO 4 + 3NAOH \u003d Na 3 PO 4 + 3H 2 O;
2H 3 PO 4 + 3NA 2 CO 3 \u003d 2NA 3 PO 4 + 3H 2 O + 3CO 2.
Obtaining sodium phosphate in industry
In industry, sodium phosphate is obtained in two stages.
First, the Na 2 CO 3 soda with phosphoric acid H 3 PO 4 is obtained with sodium phosphate Na 2 HP0 4:
H 3 P0 4 + Na 2 C0 3 \u003d Na 2 HP0 4 + C0 2 + H 2 0,
and then the interaction of the caustic natra NaOH with the resulting sodium hydrophosphate Na 2 HP0 4 is obtained by sodium phosphate Na 3 PO 4:
Na 2 HP0 4 + Na0H \u003d Na 3 P0 4 + H 2 0.
After cooling neutralized solutions up to 30 ° C, sodium phosphate crystallizes in the form of Na 3 PO 4 · 12H 2 O. It melts at 70 ° C. In order to obtain anhydrous sodium phosphate, the crystal hydrate is calcined 2 hours at a temperature of 120 ° C, and then 30 minutes at 800 ° C.
Application
Sodium phosphate to everyday life is used as a cleaning agent, as it launders fat. Thanks to this property, it is also part of the detergent. In addition, sodium phosphate softens the water, translating the salt of stiffness into insoluble phosphates:
3CA (HCO 3) 2 + 2NA 3 P0 4 \u003d 6NAHCO 3 + Ca 3 (P0 4) 2 ↓,
3mg (HCO 3) 2 + 2NA 3 P0 4 \u003d 6NAHCO 3 + MG 3 (P0 4) 2 ↓.
It also applies in the glass industry to obtain optical glasses.
In construction, sodium phosphate is used to harden the concrete. Its additive also increases the moisture resistance of concrete, as it becomes less porous.
In medicine, sodium phosphate occasionally is used as a laxative and remedy for heartburn.
In the food industry, it is known as the dietary supplement E339 (III). Sodium phosphate is used as an emulsifier, a stabilizer, a moisture-hold agent. It is added to mayonnaise and ketchups, melted cheeses and bakery products, the hydrophosphate (food additive E339 (I)) and sodium dihydrophosphate (food additive E339 (III)) are used more often. Sodium phosphate is treated with chicken ham, meat and fish to keep water and save weight.
Refers to low hazardous substances (4 class of danger), but in the overdose of food, leads to digestive disorders, and children often cause excitation and hyperactivity.
An example of solving the problem
How many sodium phosphate is obtained by neutralization with phosphoric acid 240 g of caustic soda?
Decision.
240 g - x g
H 3 PO 4 + 3NAOH \u003d Na 3 PO4 + 3H 2 O.
3 praying - 1 mol
3 * (23 + 16 + 1) \u003d 120 g
3 * 23 + 31 + 4 * 16 \u003d 164 g
We compile proportion:
120 g NaOH - 164 g Na 3 PO 4,
240 g NaOH - XG Na 3 PO 4.
x \u003d (240 * 164) / 120 \u003d 328
Sodium phosphate (E339III, TSP, three-stage sodium phosphate, sodium trifosphate, trinitium phosphate, sodium orthophosphate) - Ortophosphoric acid salt
Physiochemical properties.
Sodium phosphate has three varieties:
1) formula Na 3 PO 4 (E339III, TSP, sodium is anhydrous phosphate). Appearance: Colorless crystals. Melting point 1340 ° C. Density: 2.536 g / cm 3. Pumping losses for no more than 2% (120 ° C with an excerpt of 2 hours, then 800 ° C with an excerpt of 30 minutes). Insoluble substances in water not more than 0.2%.
2) Formula Na 3 PO 4 × H 2 O (E339III, TSP, sodium phosphate monohydrate). Appearance: Colorless crystals or granules. Easily soluble in water; not soluble in ethanol. Loss when calcining no more than 11% (120 ° C with an excerpt of 2 hours, then 800 ° C with an excerpt of 30 minutes). Insoluble substances in water not more than 0.2%.
3) Formula Na 3 PO 4 × 12 H 2 O (E339III, TSP, sodium phosphate dodechydrate). Appearance: Colorless trigonal crystals. Contains small impurities sodium hydroxide. Melting temperature in crystallization water 73.4 ° C. The temperature of the start of expansion is 100 ° C, the total decomposition is not achieved even at 200 ° C. Decomposes on sodium phosphate and water. Density 1.64 g / cm 3. Soluble in water. In water, almost completely hydrolyzed on Na 2 HPO 4 and NaOH and has a strongly alkaline reaction. Normally soluble in the servo carbon. Losses with calcination not more than 45-58% (120 ° C with an excerpt of 2 hours, then 800 ° C with an excerpt of 30 minutes). Insoluble substances in water not more than 0.2%.
The pH value of 1% aqueous solutions from 11.5 to 12.5.
Sodium phosphate at room temperature has relatively weak solubility. It is even worse, it dissolves in salted and acidic water. Therefore, in the food production in the preparation of marinades, the source water is heated, primarily dissolve the sodium phosphate or a mixture of phosphates, and then, after cooling, other ingredients contribute (the cream salt, etc.).
| Name of food additive | Coefficient recalculation |
| Phosphoric Anhydride P 2 O 5 | 1,000 |
| Sodium Anhydrous Phosphate Na 3 PO 4 (E339III) | 2,31 |
| Sodium Phosphate Monohydrate Na 3 PO 4 × H 2 O (E339III) | 2,56 |
| Sodium Phosphate Dodecahydrate Na 3 PO 4 × 12 H 2 O (E339III) | 5,35 |
Sodium phosphate is not considered to be direct preservative. It is considered to be a light bacteriostatic, because It slows down the growth of some gram-positive bacteria: Leuconostoc Carnosum, Listeria Monocytogenes, Staphylococcus Aureus, Bacillus Cereus, Bacillus Stearothermophilus, Bacillus Brevis, Bacillus Subtilis, Bacillus Sphaericus, Bacillus Sp., Micrococcus Luteus, CoryNebacterium Glutamicumand slightly affects gram-negative bacteria: Salmonella Typhimurium, Salmonella Enteritidis, Escherichia Coli.
Application.
Three-substituted phosphate sodium technical It is used as a component of detergents, surfactants in the production of cements and when drilling wells; In drilling solutions in the complex polymer additive to low grade clays and powders.
Three-substituted phosphate sodium food Applied as a buffer agent, sequestrant, emulsion stabilizer.
Processing meat and meat products with solutions of sodium phosphate leads to a change in pH inside the product. As a result, the electrostatic forces between the actine and the mosine occurs, and the sequestration of metal cations is the formation of complex compounds through the binding of phosphates and metal cations (for example, Ca 2+, Mg 2+, Fe 2+, Fe 3+). The processed product is less susceptible to loss of moisture, the development of gram-positive bacteria, oxidative ferryness. In addition, treated meat products are able to keep water, which in the meat was originally absent and was made in any technological way.
Chicken thigh treatment recipe for E339III solution to improve color and smell.
Sodium phosphate can be applied to improve the sensory properties of cooled chicken thighs, whose storage temperature is + 2 ° C. For this, aqueous solution of phosphate sodium with a concentration of 10-12% is prepared. The weight of the chicken thighs to the volume of the solution is 1: 4. The hips are immersed in solution at a temperature of + 20 ° C for 15 minutes. After treatment with a solution, chicken thighs are stored at a temperature of + 2 ° C. As a result of processing, chicken thighs on the day of processing have the best color and smell than not processed. But after seven days of storage, the color, smell and taste of the processed chicken thighs are worse than the chicken thighs without processing.
Sodium phosphate is part of solutions for disinfection and washing equipment at enterprises manufacturing fruit and vegetable canned food, dried fruits, vegetables and potatoes, sauer cabbage and salted vegetables, as well as processing meat, fish and milk.
The sanitary rules are allowed to use sodium phosphate for purposes and concentrations specified in the table below. Processing produced by spraying the solution.
| Object washing | Stainless equipment. Steel or other metal with tin coating | Tables, doors, floor, window sills | Aluminum-made equipment | Equipment in contact with hot milk (except made of aluminum) - to remove the milk stone | Glass Pipelines, Banks, Bottles, Enameled Tanks |
| Sodium phosphate (% by weight) | 0,18-0,70 | 3,50 | 0,50 | 0,35 | 0,15-0,30 |
| Caustic Soda (% by weight) | - | - | - | 0,10 | 0,32-0,65 |
| Soda calcined (% by weight) | 0,05-0,20 | 1,00 | 0,50 | 0,50 | - |
| Liquid glass (% by weight) | 0,25-0,10 | 0,50 | 1,70 | 0,05 | 0,03-0,05 |
Sodium phosphate is allowed for use on preschool food institutions (nursery, nursery, kindergartens).
For this, the dishes are carefully cleaned from food residues, washed in hot water (temperature 50 - 60 ° C) with the addition of sodium trifhosphate at the rate of 100 - 200 g per 10 liters of water. After that, they are powered with boiling water and dry on the lattice shelves. Spoons and forks are wedged as well as the dining room, and then fall 15 minutes in boiling water. Tea utensils washes apart from the dining room in two waters at a temperature of 50 - 70 ° C.
Sodium phosphate is used in solutions for processing the inner surface of the water pipes before applying paintwork coatings, such as: corsop copolymer (TU 38-103118-72), Paint HC-720 (TU 6-10708-74), HS-710 enamel (GOST 9355 -81), polystyrene resin cors (TU 38-30322-81), etc. Including with the use of filler consisting of 10 - 15% aluminum powder PAP-2 (GOST 5494-71).
The essence of processing is degreasing by immersion in stationary baths. Degreases are produced at 70-90 ° C. The duration of degreasing depends on the amount of contamination and is usually 3 - 10 minutes. The quality of degreasing is checked by an external inspection. Well low fat surface is uniformly wetted with water. If there are residual pollution residues, water on the metal surface is collected by drops.
Sodium phosphate is part of the solutions of the recommended Ministry of Emergency Situations for the sanitary processing of the property, which was infected with the controversy with bacteria. Such property includes: Facial parts of gas masks, protective raincoats, rubber gloves, rubber boots, H / b clothing, tarpaulin.
The treatment solution consists of sodium phosphate and sulfanol (3.5 and 2 kg per 450 liters of water). Disinfecia duration should be 1 hour. Processing is performed in boiling method containers. At the same time, the design of used containers should ensure the exclusion of the objects of the property. Upon completion of processing and draining solutions, the property is washed first hot, then with cold water. Washing can be done in boiling tanks. The processed property is dried in summer in dry weather in the open air, in winter and rainy weather use any tents or closed rooms.
In machine-building enterprises, parts entering the assembly are purified and washed from foreign particles, oil, traces of coolant or conservation coating.
A solution is used as a detergent for aluminum parts, which includes: sodium phosphate 30 g / l and soda calcined by 30 g / l.
Sodium phosphate is used to fulfill the requirements of the water-chemical mode during the operation of the electrode boilers. Sodium phosphate additives are made in water that enters the boiler. Such an additive reduces the specific electrical resistance of water by reducing scale to normalized values. This maintains the energy efficiency of the boiler, and also increases the interregnation period.
The magnitude of the addition of sodium phosphate depends on the composition of the initial nutrient water of the boiler, as well as from the mode of operation (water heating, steam) boiler and its structural features. The calculation of the value of the additive is made on the basis of theoretical calculation and subsequent experienced verification.
Corrosion products during the operation of boilers are formed not only during the boiler operation, but also during periods of stopping boilers for repair or stops during the accident. In order to avoid this boiler you need to preserve. One of the methods of preservation is to fill the internal volume of the boiler with a solution of phosphate sodium solution. The sodium concentration of phosphate depends on the composition of water. For condensate - 5 kg / m 3; For water containing up to 3 g of salts of 1kg of water - 20 kg / m 3.
Sodium phosphate is used in everyday life for cleaning dishes from scale. To do this, use 20-30 g of powder, it is necessary to pour into contaminated dishes, pour hot water and boil 1-2 hours, after which it can be easily screamed with a brush and rinse thoroughly with clean water. If the scale is not immediately deleted, the processing must be repeated.
Introduction to the concrete mixtures of sodium phosphate improves the disorders of the mixtures and increases the strength of concrete. The additive of the trinitium phosphate in an amount of 0.5% of the mass of cement increases the strength of concrete (by 28 days) by 20%.
This additive reduces the volume of open pores and increases the volume of closed pores, which significantly increases the waterproofability and frost resistance of concrete. The additive of the trinitium phosphate in the amount of 0.5% of the cement mass changes the waterproof of concrete from the brand B-2 to the brand B-4, and the frost resistance rises more than 2 times.
Getting.
Sodium phosphate is synthesized by condensation with orthophosphoric acid.
Definition
Under normal conditions sodium phosphate It is a hygroscopic thermally stable white powder (Fig. 1), whose crystals melt without decomposition.
It is well soluble in water (hydrolyzed), creating an alkaline environment.
Fig. 1. Sodium phosphate. Appearance.
The main characteristics of sodium phosphate are shown in the table below:
Obtaining sodium phosphate
Laboratory methods for producing sodium phosphate suggest an action of orthophosphoric acid on sodium salts (1) or sodium hydroxide (2):
3NA 2 CO 3 + 2H 3 PO 4 \u003d 2NA 3 PO 4 + 3CO 2 + 3H 2 O (1);
3NAOH + H 3 PO 4 \u003d Na 3 PO 4 + 3H 2 O (2).
Chemical properties of sodium phosphate
Sodium phosphate is a medium salt formed by a strong base - sodium hydroxide (NaOH) and weak acid - orthophosphoric (H 3 PO 4). In an aqueous solution is hydrolyzed. Hydrolysis flows through anion (theoretically possible second and third level). The presence of anions it indicates an alkaline nature of the environment.
First stage:
Na 3 PO 4 ↔ 3NA + + PO 4 3-;
3NA + + PO 4 3- + HOH ↔ HPO 4 2- + 3NA + + OH -;
Na 3 PO 4 + HOH ↔ Na 2 HPO 4 + NaOH.
Second step:
Na 2 HPO 4 ↔ 2NA + + H 2 PO 4 -;
2NA + + H 2 PO 4 - + HOH ↔ NaHPO 4 + 2NA + + OH -;
Na 2 HPO 4 + HOH ↔ NaHPO 4 + NaOH.
Third stage:
NaHPO 4 ↔ Na + + PO 4 3-;
Na + + PO 4 3- + HOH ↔ H 3 PO 4 + Na + + Oh -;
NaHPO 4 + HOH ↔ H 3 PO 4 + NaOH.
For sodium phosphate, all properties of salts are characterized:
- Interaction with strong mineral acids
Na 3 PO 4 + 3HCl \u003d 3NACL + H 3 PO 4;
- Interaction with salts, as a result of which one of the reaction products is insoluble in water
2NA 3 PO 4 + 3Li 2 SO 4 \u003d 2Li 3 PO 4 ↓ + 3NA 2 SO 4;
- decomposition when heated
Application of sodium phosphate
Sodium phosphate found use in the food industry - E542 additive used in the production of pasta, fermented milk products, meat and culinary semi-finished products. It is also a component of a toothpaste and some cosmetic drugs.
Examples of solving problems
Example 1.
| The task | What is the mass of phosphorus oxide (V) is formed during the response of thermal decomposition of sodium phosphate weighing 200 g? |
| Decision | We write the sodium phosphate thermal decomposition equation: 2NA 3 PO 4 \u003d P 2 O 5 + 3NA 2 O. Calculate the amount of sodium phosphate substance (molar mass - 164 g / mol): n (Na 3 PO 4) \u003d M (Na 3 PO 4) / M (Na 3 PO 4); n (Na 3 PO 4) \u003d 200/164 \u003d 1.22mol. According to the reaction equation N (Na 3 PO 4): N (P 2 O 5) \u003d 2: 1. Then the amount of phosphorus oxide (V) will be equal to: n (p 2 O 5) \u003d ½ × n (Na 3 PO 4) \u003d ½ × 1,22 \u003d 0.61mol. We will find a mass of phosphorus oxide (V) (molar mass - 284 g / mol): m (P 2 O 5) \u003d n (P 2 O 5) × M (P 2 O 5) \u003d 0.61 × 284 \u003d 173.24 |
| Answer | The mass of the formation of phosphorus oxide (V) is equal to 173.24. |
Sodium phosphate or sodium phosphate (eng. Sodium phosphate.) - the general name of a number of sodium salts of phosphoric acids.
Sodium phosphates used in pharmaceutical and food industry
Historically, each of the phosphate sodium compounds has several items, both in Russian and English. The following are some such names and chemical formulas of the most common sodium phosphates in medicine and food industry:
Sodium phosphates in medicine
Sodium salts of phosphoric acids in medicine are used as laxatives, as part of antacid agents, as well as to maintain a mineral balance and acid-alkaline blood equilibrium. In addition, they are often involved in drugs like excipients.The laxative effect of phosphate sodium is based on increasing and delayed fluid in the intestine due to osmotic processes. The accumulation of fluid in the colon leads to the strengthening of the peristaltics and defecation.
Sodium phosphate compounds have contraindications, side effects and features of application, consultation with a specialist is necessary.
Sodium phosphate - Food additive
The composition and requirements for food additives - sodium salts of phosphoric acid regulates "GOST R 52823-2007. Food additives. Sodium phosphates E339. General specifications. " This GOST extends to the food additive of sodium phosphates E339, which is 1-substituted (I), 2-substituted (II) and 3-substituted (III) sodium solids of orthophosphoric acid (hereinafter - sodium food monophosphates) and intended for use in the food industry . GOST subdivides all nutritional supplements E339 - sodium monophosphates for three types:- E339 (I), sodium orthophosphate 1-substituted (sodium dihydrophosphate)
- E339 (II), sodium orthophosphate 2-substituted (sodium hydrophosphate)
- E339 (III), sodium orthophosphate 3-substituted (sodium phosphate).
Sodium phosphate is a frequent "satellite" of many foods. It can also be detected in the composition of synthetic detergents. And despite the fact that this substance is potentially dangerous to human health, in many countries of the world its use is not prohibited, and Russia is also included in the list of these states.
Characteristic of substance
Sodium phosphate refers to a number of sodium salts of phosphate acids.
His physical properties will be as follows:
- this substance is some white granules or crystals;
- in water is soluble well;
- it is thermally stable.
Technological functions
In industrial production, the E339 additive performs such functions:
- an acidity regulator that helps maintain the required level pH;
- stabilizer - gives the product a certain texture, form, is directly involved in the formation and safety of the consistency;
- emulsifier - helps to connect substances that are not mixed under normal conditions.
Types of phosphate
There are three types of sodium phosphates, which will be different to the chemical formula and nomenclature value, with which they can be recognized on the product labels:
- single-dismedified phosphate, or an additive E339 (I) - Na2PO4;
- double phosphate, or E339 (II) additive - Na2HPO4;
- three-substituted phosphate, or additive E339 (III) - Na3PO4.
Harmful effects
Sodium phosphate harm manifests itself depending on the type of product in which it enters. For example, synthetic detergents with its content have an adverse effect on the skin, and it is manifested in the form of allergies - ravis, and in particularly severe situations eczema develops.
Foods containing in their composition additive with an E339 index possess a broader spectrum of harmful properties that manifest themselves as:
- diarrhea;
- gastritis;
- stomach ulcer;
- calcium exchange violation;
- malignant neoplasms in the gastrointestinal tract.
What is sodium phosphate for a child?
The children's body is more susceptible to the influence of such substances and its reaction is manifested in the form of nervous and mental disorders.
The child can be observed:
- motor anxiety;
- hyperactivity;
- impulsiveness;
- aggression;
- anxiety;
- reducing the concentration of attention.
On a note! What is characteristic, if the menu remove products containing the E339 additive, then all the symptoms will gradually go to no and will soon be completely disappeared without the use of medication treatment!
Application
In the non-functional industry, calcium phosphate is part of the washing and cleaning powders. And the list of foods containing this harmful additive looks like this:
- bakery and confectionery, where it performs the function of the baking powder;
- dairy products - milk, dry cream, condensed milk, where it is used as an anti-crystallizer and a substance that helps increase the storage time of finished products;
- cheeses, mostly melted - sausage, fragile, pasty, where it is used as a soloplamator.
On a note! In the manufacture of all the above-described foods, the sodium phosphate is used two-fold!
In addition, the E339 additive can be found on packages of meat products, dry broths and soups, sauces, tea bags.
All materials on the site site are presented solely for informing information purposes. Before applying any means, consultation with the doctor is obligatory!
Updated: 26-04-2019