E172 effect on the body. E172 - all colors of rust. Interaction with halogens and sulfur at high temperature

The fact that E172 is almost never eaten in Russia is more a tribute to tradition than health care. There are many other "inedible" dyes, iron oxide among them is not the most exotic or repulsive. But if you come across red chocolate or brown pâté in Europe, it is very likely that they contain E172.

The additive under the code classification number E 172 is a powdery substance of a red hue. In a chemical sense, this additive is a combination of oxygen and iron.

The natural source of this substance are the minerals hematite and magnetite, but for the use of additives in food, it is obtained synthetically. Either by the interaction of iron and water vapor at high temperatures, or by calcining iron oxides.

Origin: 2-synthetic;

Danger:extremely low level

Synonymous names:E 172, E-172, iron oxide, Iron Oxides and Hydroxides.

​General information

In food production, this type of additive is used to give a certain color to food products. This substance can give foods a variety of hues, from red to black, including orange, yellow, and brown.

There are 16 types of iron oxides in total. But in food production, only three are used:

• Iron oxide (II, III), which is a complex oxide, combines iron (II) and (III) ions, and in the form of a chemical molecular formula it looks like this: Fe 3 O 4. In wildlife, it can be found in the form of a magnetic mineral. Marked E 172(i).
• Iron oxide (III), which in the form of a molecular formula looks like this: Fe 2 O 3, and in wildlife it can be found in the form of the mineral hematite (and in everyday life it is called ordinary rust). Marked E 172(ii).
• Iron oxide (II), which in the form of a molecular formula looks like this: FeO. And in wildlife it can be found in the form of the mineral wustite. Marked E 172(iii).

Effect on the body

Harm

The E 172 additive itself is considered harmless, and even in some cases beneficial to the human body. But when there is an excess of it in the body, it is fraught with very tangible negative consequences. When a high level of iron concentration is noted, free radicals are produced in the body, and this invariably leads to diseases such as myocardial infarction or.

If iron accumulates in the liver, it is fraught with tumor diseases of this organ, and in a malignant form. True, this type of pathology is characteristic only of those people who have such a genetic disease as.

Benefit

In the maximum permissible small dosages, iron brings considerable benefits to the human body. First of all, the level of hemoglobin in the blood directly depends on it.

And under the condition of a normal state of metabolic processes in the body, iron oxide (with its reasonable consumption) is processed by 100% and excreted along with urine and feces.

Usage

In food production, this dye additive is used in confectionery, chocolate, dragees, and other products.

In addition to the food industry, it is used in metallurgy as a raw material for the production of various metals; in the paint and varnish industry (as a color pigment); in the chemical industry (as a catalyst); in cosmetology (mainly for decorative cosmetics); in pharmacology (for drugs that increase the level of hemoglobin in the blood).

Legislation

In almost all countries of the world, food coloring under the code code E 172 is allowed for use in food production.

Characterization and obtaining

E172 is a food coloring that combines three forms of iron oxides. It is odorless and tasteless, looks like a powder or paste. Spectrum of shades - black, brown, red, orange, yellow. Iron oxides are found in the natural environment, but for industrial use, a synthetic method for obtaining E172 is used.

There are 16 forms of iron oxides, but only three are used in the food industry:

The substance is highly soluble in inorganic acids and insoluble in water, organic solvents and vegetable oils. Retains properties when exposed to light, heat, fruit acids and alkalis.

Purpose

Iron oxide is involved in the production of food, giving them the necessary shade. The substance serves as a durable pigment in paints. Acts as a raw material for the manufacture of metals. The additive is used in the cosmetic, pharmaceutical and chemical industries.

Impact on the health of the human body: benefits and harms

Additive E172 is not harmful to health if consumed within the established norm. No more than 0.5 mg of a substance per kilogram of weight can enter the body per day. Too much iron leads to the formation of free radicals, which can cause heart attack, myocardial infarction, and stroke.

In patients with hemochromotosis, the accumulation of iron can provoke the development of liver cancer. But the dye E172, which contains iron, once in a healthy body, is completely processed and excreted. Thus, it does not harm health if the prescribed dosage is observed.

Applications

The food industry includes the additive E172 in the composition of products in order to color them in the desired color. Often the dye is used to give a black tint to artificial caviar (especially in Russia).

Iron oxide is stained with:

• dragee, chocolate, sweets;
• baking mixes;
• meat and fish pate;
• pet food;
• confectionery;
• product decorations;
• dairy desserts.

Other applications of iron oxides:

• metallurgy (raw materials for the manufacture of metals);
• cosmetology (painting foundation, powder, eyelash dye, etc.);
• pharmaceuticals (coloring preparations in the form of creams, powders, dragees; for the production of drugs that increase hemoglobin);
• chemical industry (acts as a catalyst);
• paint and varnish production (pigment in the composition of coatings and paints).

Content in products according to regulations

Table. The content of the food additive E172 in products according to SanPiN 2.3.2.1293-03 dated 05/26/2008

Legislation

The use of dye E172 is allowed in almost all countries. It is used in Russia, Ukraine, European countries, USA, Canada and many other countries.

Iron(III) oxide

TU 6-09-1404-76

Fe2O3

Iron(III) oxide- a complex inorganic substance, a compound of iron and oxygen with the chemical formula Fe 2 O 3.

Iron(III) oxide is an amphoteric oxide with a large predominance of basic properties. Red-brown. Thermally resistant to high temperatures. Formed when iron burns in air. Does not react with water. Reacts slowly with acids and alkalis. It is reduced by carbon monoxide, molten iron. It melts with oxides of other metals and forms double oxides - spinels.

In nature, hematite is found as a widespread mineral, the impurities of which cause the reddish color of laterite, red earths, and also the surface of Mars; another crystalline modification occurs as the mineral maghemite.

Iron oxide Fe 2 O 3 is a red-brown to black-violet crystals. The chemical is thermally stable. No reaction with water. Slow reaction with alkalis and acids.

Iron oxide Fe 2 O 3 is used as a raw material for iron production in the blast furnace process. This chemical is a catalyst in the ammonia production process. It is included in ceramics as one of the components, it is used in the manufacture of mineral paints and colored cements. Iron oxide Fe2O3 is effective in thermal welding of steel structural elements. The recording of sound and images on magnetic media is associated with this substance. Fe2O3 is a quality polishing agent for polishing steel and glass parts.

In minium iron is the main component. Fe 2 O 3 in the food industry is a fairly common food additive E172.

Fe 2 O 3 is used in iron smelting in the blast furnace process, a catalyst in the production of ammonia, a component of ceramics, colored cements and mineral paints, in thermite welding of steel structures, as a carrier of analog and digital information (for example, sound and image) on magnetic tapes (ferrimagnetic γ -Fe 2 O 3), as a polishing agent (crocus red) for steel and glass.

In the food industry, it is used as a food coloring (E172).

In rocket modeling, it is used to obtain catalyzed caramel fuel, which has a burning rate 80% faster than conventional fuel.

It is the main component of iron minium (kolkotar).

In the petrochemical industry, it is used as the main component of a dehydrogenation catalyst in the synthesis of diene monomers.

Ferrous compounds

I . Iron(II) hydroxide

It is formed by the action of alkali solutions on iron (II) salts without air access:

FeCl 2 + 2 KOH \u003d 2 KCl + F e (OH) 2 ↓

Fe (OH) 2 is a weak base, soluble in strong acids:

Fe(OH) 2 + H 2 SO 4 = FeSO 4 + 2H 2 O

Fe(OH) 2 + 2H + = Fe 2+ + 2H 2 O

Additional material:

Fe (OH) 2 - also exhibits weak amphoteric properties, reacts with concentrated alkalis:

Fe( Oh) 2 + 2 NaOH = Na 2 [ Fe( Oh) 4 ]. a tetrahydroxoferrate salt is formed ( II) sodium

When Fe (OH) 2 is calcined without air access, iron oxide (II) FeO is formed -black connection:

Fe(OH) 2 t˚C → FeO + H 2 O

In the presence of atmospheric oxygen, a white precipitate Fe (OH) 2, oxidizing, turns brown - forming iron (III) hydroxide Fe (OH) 3:

4Fe(OH) 2 + O 2 + 2H 2 O = 4Fe(OH) 3 ↓

Additional material:

Iron (II) compounds have reducing properties, they are easily converted into iron (III) compounds under the action of oxidizing agents:

10FeSO 4 + 2KMnO 4 + 8H 2 SO 4 = 5Fe 2 (SO 4) 3 + K 2 SO 4 + 2MnSO 4 + 8H 2 O

6FeSO 4 + 2HNO 3 + 3H 2 SO 4 = 3Fe 2 (SO 4) 3 + 2NO + 4H 2 O

Iron compounds are prone to complex formation:

FeCl 2 + 6NH 3 \u003d Cl 2

Fe(CN) 2 + 4KCN = K 4 (yellow blood salt)

Qualitative reaction for Fe 2+

Under action hexacyanoferrate (III) potassium K 3 (red blood salt) on solutions of salts of divalent iron is formed blue precipitate (turnboule blue):

3 Fe 2+ Cl 2 + 3 K 3 [ Fe 3+ ( CN) 6 ] → 6 KCl + 3 KFe 2+ [ Fe 3+ ( CN) 6 ]↓

(turnbull blue - hexacyanoferrate ( III ) iron ( II )-potassium)

Turnbull blue very similar in properties to Prussian blue and also served as a dye. Named after one of the founders of the Scottish dye firm Arthur & Turnbull.

Ferric compounds

I . Iron(III) oxide

It is formed during the combustion of iron sulfides, for example, during the firing of pyrite:

4 FeS 2 + 11 O 2 t ˚ C → 2 Fe 2 O 3 + 8 SO 2

or when calcining iron salts:

2FeSO 4 t˚C → Fe 2 O 3 + SO 2 + SO 3

Fe 2 O 3 - oxide to red-brown, slightly amphoteric

Fe 2 O 3 + 6HCl t˚C → 2FeCl 3 + 3H 2 O

Fe 2 O 3 + 6H + t˚C → 2Fe 3+ + 3H 2 O

Fe 2 O 3 + 2 NaOH + 3 H 2 O t ˚ C → 2 Na [ Fe (OH ) 4 ],a salt is formed - tetrahydroxoferrate ( III) sodium

Fe 2 O 3 + 2OH - + 3H 2 O t˚C → 2 -

When fused with basic oxides or carbonates of alkali metals, ferrites are formed:

Fe 2 O 3 + Na 2 O t˚C → 2NaFeO 2

Fe 2 O 3 + Na 2 CO 3 \u003d 2NaFeO 2 + CO 2

II. Iron hydroxide ( III )

It is formed by the action of alkali solutions on ferric iron salts: it precipitates as a red-brown precipitate

Fe(NO 3) 3 + 3KOH = Fe(OH) 3 ↓ + 3KNO 3

Fe 3+ + 3OH - \u003d Fe (OH) 3 ↓

Additionally:

Fe (OH) 3 is a weaker base than iron (II) hydroxide.

This is explained by the fact that Fe 2+ has a smaller ion charge and a larger radius than Fe 3+ , and therefore, Fe 2+ holds hydroxide ions weaker, i.e. Fe(OH) 2 dissociates more easily.

In this regard, iron (II) salts are hydrolyzed slightly, and iron (III) salts are very strongly hydrolyzed.

Hydrolysis also explains the color of solutions of Fe (III) salts: despite the fact that the Fe 3+ ion is almost colorless, the solutions containing it are colored yellow-brown, which is explained by the presence of iron hydroxoions or Fe (OH) 3 molecules, which are formed due to hydrolysis :

Fe 3+ + H 2 O ↔ 2+ + H +

2+ + H 2 O ↔ + + H +

+ + H 2 O ↔ Fe(OH) 3 + H +

When heated, the color darkens, and when acids are added, it becomes lighter due to the suppression of hydrolysis.

Fe (OH) 3 has a weakly pronounced amphoterism: it dissolves in dilute acids and in concentrated alkali solutions:

Fe(OH) 3 + 3HCl = FeCl 3 + 3H 2 O

Fe(OH) 3 + 3H + = Fe 3+ + 3H 2 O

Fe(OH) 3 + NaOH = Na

Fe (OH) 3 + OH - \u003d -

Additional material:

Iron (III) compounds are weak oxidizing agents, they react with strong reducing agents:

2Fe +3 Cl 3 + H 2 S -2 = S 0 ↓ + 2Fe +2 Cl 2 + 2HCl

FeCl 3 + KI \u003d I 2 ↓ + FeCl 2 + KCl

Qualitative reactions for Fe 3+

Experience

1) On action potassium hexacyanoferrate (II) K 4 (yellow blood salt) on solutions of salts of ferric iron is formed blue precipitate (Prussian blue):

4 Fe 3+ Cl 3 + 4 K 4 [ Fe 2+ ( CN) 6 ] → 12 KCl + 4 KFe 3+ [ Fe 2+ ( CN) 6 ]↓

(prussian blue - hexacyanoferrate ( II ) iron ( III )-potassium)

Prussian blue was obtained by chance at the beginning of the 18th century in Berlin by the dyesmith Diesbach. Disbach bought an unusual potash (potassium carbonate) from a merchant: a solution of this potash turned blue when iron salts were added. When checking the potash, it turned out that it was calcined with bull's blood. The dye turned out to be suitable for fabrics: bright, stable and inexpensive. Soon the recipe for obtaining paint became known: potash was fused with dried animal blood and iron filings. By leaching such an alloy, yellow blood salt was obtained. Prussian blue is now used to produce printing ink and tint polymers.

It has been established that Prussian blue and Turnbull blue are the same substance, since the complexes formed in the reactions are in equilibrium with each other:

KFe III[ FeII( CN) 6 ] ↔ KFeII[ Fe III( CN) 6 ]

2) When adding potassium or ammonium thiocyanate to a solution containing Fe 3+ ions, an intense blood-red color appears solution iron(III) thiocyanate:

2FeCl 3 + 6KCNS = 6KCl + Fe III[ Fe III( CNS) 6 ]

(when interacting with Fe 2+ ions with thiocyanates, the solution remains almost colorless).

simulators

Simulator No. 1 - Recognition of compounds containing the ion Fe (2+)

Simulator No. 2 - Recognition of compounds containing the ion Fe (3+)

Tasks for fixing

№1. Perform transformations:
FeCl 2 -> Fe(OH) 2 -> FeO -> FeSO 4
Fe -> Fe(NO 3) 3 -> Fe(OH) 3 -> Fe 2 O 3 -> NaFeO 2

No. 2. Write the reaction equations to get:
a) salts of iron (II) and salts of iron (III);
b) iron (II) hydroxide and iron (III) hydroxide;
c) iron oxides.