Magnesium Sulfate Anhydrous is an inorganic compound formed by the combination of magnesium and sulfate ions. Compared to the common heptahydrate magnesium sulfate (diuretic salt), it has completely lost all its crystalline water, thus exhibiting extremely strong hygroscopicity. In organic chemistry, it is a standard desiccant used for drying organic phases; in the fields of medicine and nutrition, it is an efficient supplement of magnesium.

CAS Number: 139939-75-6 (Synonym Reference Number: 7487-88-9)

Molecular formula: MgSO₄

Molecular weight: 120.37 g/mol

EINECS Number: 231-298-2

Technical Specifications

Product features

Extremely strong hygroscopicity:

This is its most notable chemical property. It can quickly absorb moisture from the air, and thus is widely used as a desiccant for inert organic solvents. When drying the organic phase, it forms the hydrated MgSO₄·7H₂O compound with water, and the moisture can be removed through filtration.

High purity and chemical inertness:

Compared to drying agents such as calcium chloride or sodium hydroxide, anhydrous magnesium sulfate does not undergo side reactions with most organic compounds (such as esters, amides, etc.), and is therefore highly suitable for use in systems with substances sensitive to acids and bases.

High magnesium content:

Due to the absence of crystalline water, the effective content of magnesium ions in it is much higher than that of magnesium sulfate heptahydrate (in magnesium sulfate heptahydrate, the effective component of magnesium sulfate is only approximately 48.8%). In analyses or formulations that require precise magnesium ion concentration, using anhydrous magnesium sulfate can avoid a 2.05-fold mass conversion error, ensuring the accuracy of measurement.

Core Strengths

• The reliability of quantitative analysis: According to the USP (United States Pharmacopeia) standards, the content is strictly controlled within the range of 99.0% - 100.5%, and the loss on ignition is extremely low. This definite stoichiometric ratio makes it the preferred choice for preparing standard solutions, weight analysis, and formulation of pharmaceutical preparations.

• High drying efficiency: The drying process is fast, and the granular form is convenient for subsequent filtration and separation. It is one of the most commonly used "inert" drying agents in laboratories.

• High bioavailability: In animal nutrition research, magnesium derived from anhydrous magnesium sulfate has a significantly higher bioabsorption rate than inorganic magnesium sources such as magnesium oxide (studies have shown that the bioavailability of magnesium oxide is 22%-40% lower than that of magnesium sulfate), which means that a lower dosage can achieve the desired magnesium supplementation effect.

Main purpose

Organic Synthesis and Laboratory: As an efficient desiccant, it is used to dry organic liquids such as ethers and alkanes.

Medicine and Pharmacy:

• Active pharmaceutical ingredients: Used for preparing laxatives, anticonvulsants (such as for controlling eclampsia), and as excipients in various medications.

• Nutritional supplement: Used to control the concentration of magnesium ions in the plasma, it has a longer retention time in the body compared to magnesium citrate (with lower urine excretion).

Agriculture and Feed:

• Fertilizer: Provides two essential macronutrients, sulfur and magnesium. It is particularly suitable for hydroponic cultivation of economic crops and flowers.

• Feed additives: As a source of magnesium in the diets of ruminants and poultry, they prevent magnesium deficiency convulsions.

• Industry and Cosmetics: Preparation of mordants for the dyeing industry, refractory materials, paper filler agents, and bath salts.

Packaging and Storage/Transport

Packaging specification: Usually in 25kg per bag (in woven bags or paper-plastic composite bags), or we can also provide 500g or 1kg laboratory vials.

Storage conditions: It must be stored in a sealed manner in a dry, cool, and well-ventilated warehouse. Due to its high susceptibility to moisture absorption, it should be used as soon as it is opened to avoid prolonged contact with the air.