Quick Search
CAS no.: 7558-80-7
EC / List no.: 231-449-2
Monosodium phosphate (MSP), also known as monobasic sodium phosphate and sodium dihydrogen phosphate, is an inorganic compound of sodium with a dihydrogen phosphate (H2PO4−) anion.
One of many sodium phosphates, it is a common industrial chemical.
The salt exists in an anhydrous form, as well as mono- and dihydrates.
The salt is obtained by partial neutralization of phosphoric acid.
The pKa of monosodium phosphate is 6.8-7.2
Heating this salt above 169 °C gives the corresponding sodium acid pyrophosphate:
2 NaH2PO4 → Na2H2P2O7 + H2O
Phosphates are often used in foods and in water treatment.
The pH of such formulations is generally adjusted by mixtures of various sodium phosphates, such as this salt.
The sodium chloride equivalent value, or E-Value, is 0.49.
It is soluble in 4.5 parts water.
Food additive
Monosodium phosphate added in animal feed, toothpaste, and evaporated milk.
Monosodium phosphate used as a thickening agent and emulsifier.
Detection of magnesium
Monosodium phosphate is used to detect the presence of magnesium ions in salts.
Formation of a white precipitate on the addition of ammonium chloride, ammonium hydroxide and monosodium phosphate to an aqueous or dilute HCl solution of the salt indicates presence of magnesium ions.
Animal feed, toothpaste and evaporated milk are added.
Monosodium phosphate used as a thickening agent and emulsifier.
Monosodium phosphate is used to detect the presence of magnesium ions in salts.
Monosodium phosphate used as a buffer and emulsifier in foods.
Monosodium phosphate used as an acid component in dry powdered soft drinks, effervescent powders and lactacids, and as a gelling accelerator in instant puddings, to preserve the egg yolk color before cooling.
Monosodium phosphate used in applications such as metal finishing, pH control in acid type metal cleaners, water treatment, detergents, textile, oil drilling mud, penetrating mud treatment, dispersing agent, hardness stabilization, cheese processing (emulsifying properties allow oil to disperse and melt easily).
Monosodium phosphate (NaH₂PO₄) can be prepared from a mixture of phosphoric acid and sodium chloride according to the principle that an amine in organic solution can remove the elements of hydrochloric acid (HCl).
This is possible because amines are more selective for hydrochloric acid than phosphoric acid.
If wet process phosphoric acid is used, impurities must somehow be separated from the final product.
The work described here includes examining the distribution of phosphoric acid and trivalent iron and sulfate impurities between aqueous solutions of the commercial amine Amberlite LA-1 and kerosene solute ions.
In a countercurrent extraction process, about twenty theoretical steps would be needed to reduce the iron concentration to food grade levels.
The sulfate is retained in the organic phase.
Monosodium phosphate can be recovered by stripping the organic phase with a sodium chloride solution.
Monosodium phosphate (MSP), also called sodium dihydrogen phosphate or sodium phosphate monobasic, is a multifunctional ingredient that can be used as an acid regulator, sequestrant and nutrient supplement in food with the European food additive number E339.
It is more acidic than disodium phosphate, which is alkaline.
Monosodium phosphate can be produced in two ways: partial neutralizing phosphoric acid with sodium carbonate/sodium hydroxide OR the reverse order.
MSP is an inorganic compound made from naturally occurring minerals and existing in three forms, and follows the corresponding chemical formula:
MSP Anhydrous: NaH2PO4
MSP Monohydrate: NaH2PO4 · H2O
MSP Dihydrate: NaH2PO4 ·2 H2O
Properties
Other names
Monosodium orthophosphate
Sodium biphosphate
Sodium acid phosphate
CAS number 7558-80-7
Appearance A white powder or granular
Solubility Freely soluble in water, insoluble in ethanol
PH An acid with the PH value between 4.1 and 5.0 (1% solution)
Monosodium phosphate can be used in food, chemical industry, printing and dyeing, metal clean, water treatment (corrosion control), aquaculture, and etc.
Monosodium phosphate generally recognized as safe (GRAS) when used as a nutrient and a sequestrant in food in accordance with good manufacturing practice .
And its safety has been re-evaluated by EFSA in 2019 and established an ADI expressed as phosphorus of 40 mg/kg body weight (bw) per day.
Food
Food grade monosodium phosphate is generally used in following food lists:
A buffer and acidity regulator in food
A Leavening acid in baking powder
A binder and curing agent for bread and sauce
Water retention agent
Quality improver for evaporated milk
A stabilizer for dairy products, meat, and fish products
Cheeses, sweet jellies, jams & preserves, frozen eggs, chocolate products (4)
Animal feed
As a feed additive, sodium dihydrogen phosphate is a good source of phosphorus and sodium for feed (horse) and pet food (e.g. dog, cat).
Toothpaste
When used as an ingredient in toothpaste, MSP functions as a PH control and prevents teeth cavities.
Other sodium phosphates
Sodium dihydrogen phosphate can be used to produce various sodium phosphate salts, such as sodium trimetaphosphate, sodium hexametaphosphate, sodium acid pyrophosphate and sodium polyphosphate.
Phosphates are various salts of phosphoric acid (HP3PO4).
Phosphorus is a mineral found in all living things and is important for both nutrition and other functions of the body.
However, since none of the living things are capable of synthesizing the phosphate anion, humans must obtain it from the outside through food.
Phosphates have various functions as a food additive rather than their nutritional value.
They act as chelates by forming complexes with metal ions.
They can be used for pH stabilization. In other words, they act as a buffer in food.
Since some phosphates have water binding properties, they can be used in many food products for water retention and water withdrawal.
Some phosphates are used as anti-caking agents in powder and dry mix foods.
Phosphoric acid or its acidic salts are used as acidifiers in the food industry.
Phosphate salts with alkaline character are used in the food industry to turn the environment into alkaline and raise the pH.
Due to its antimicrobial and antioxidant properties, it also has food preservative properties.
Phosphates in general:
They are important food additives used for different purposes in various foods including meat, poultry, seafood, dairy products, cereal products, fruit and vegetable products, fats and oils, alcoholic and non-alcoholic beverages.
Monosodium phosphate also used in fields such as starch industry, ripening and aromatized salts, jelly and pectin industry, egg products, sugar technology.
Due to its chemical effects on food components and other additives and chemical reactions with them, phosphates affect water binding, color, aroma, texture, coagulation, emulsification, curing process, microbial development and processing technology in various foods.
Monosodium phosphate is a compound of sodium and phosphate counter elements.
Monosodium phosphate often found in dental products due to its enamel restorative properties and is sometimes used in medicine as a laxative.
Monosodium phosphate sometimes added to toothpastes along with other ingredients to prevent cavities and restore lost enamel, but can also be purchased separately as a tooth cleaner and preservative.
Most often, monosodium phosphate comes in crystals and powder form.
Monosodium phosphate colorless and odorless.
When used for oral health purposes, it is usually dissolved in water containing one part monosodium phosphate to four and a half parts water.
This combination can be applied directly to teeth to restore enamel and prevent tooth and gum disease.
In some cases, it is also found in toothpaste and mouthwash.
Monosodium phosphate supplements are also available in food grade tablets.
These are not as effective as medicinal formulations and can be taken orally to supplement dietary phosphorus.
Horses are therefore commonly given monosodium phosphate supplements.
Monosodium phosphate important not to overdose on these supplements because they can be hard on the kidneys if taken in higher than recommended amounts.
In medicine, monosodium phosphate is sometimes used as a stimulant laxative before certain procedures and medical procedures.
This is not recommended for all patients due to the adverse reactions of the supplements on the kidneys.
Sodium and phosphorus-based laxatives have been discontinued in some countries because of these risks, as safer alternatives are available.
