Identification test
500 mg of sample was mixed with 10 ml of dilute hydrochloric acid test solution (TS-117), filtered and neutralized with ammonia test solution (TS-13) on litmus paper. The filtrate after neutralization was positive after the magnesium test (IT-21).
With platinum wire ring dipped in several ammonium phosphate crystals, melting in the colorless flame on the ball, dipped in the sample when it is hot, and then melt, the silica was floating on the surface of the ball. Having been put cold, it turns into an opaque small ball with reticular structure. Indicating that the silicon test is positive.
Solubility: insoluble in water and ethanol (OT-42);
easily decomposed in inorganic acid.
The pH of the 10% slurry was 7.0 to 10.8.
Content analysis
Analysis of the content of magnesium oxide: weigh about 1.5g sample exactly; take it into a 250ml conical flask; add 1mol/L sulfuric acid 50.0ml, in the steam bath for 1h. Cool to ambient temperature; add one drop of methyl orange test solution (TS-148), and the excess acid is titrated with 1 mol/L sodium hydroxide solution. 1mol/L sulfuric acid per milliliter is equivalent to MgO2 0.15mg.
Analysis of silica content: took about 700mg sample, weighed to 0.1mg; took it into a 150ml beaker; added 20ml 1mol/L sulfuric acid, heating in the steam bath for 1.5h; decant the supernatant, and filter it with sterile filter paper; then the residue should be washed with hot water 3 times in the beaker, and pass through the filter paper. The residue was impregnated with 25 ml of water and digested on a steam bath for 15 min. Finally, the residue was transferred to the filter paper and rinsed with hot water onto the filter paper. The filter paper and filter residue was removed into the platinum crucible. Heated to dry and burn, and then it underwent a strong burning for 30min, cooling and weighing. Wet the residue with water. 6ml of hydrofluoric acid and 3 drops of sulfuric acid was added. Evaporated to dry, and then it would stand a 5min burning, weighing after cooling. The weight lost by the sample is the weight of SiO2.
Uses
Anti-caking agent; filter aid; coating agent; candy polishing glaze; chewing gum base powder; rice coating agent; (drug) antacids. Processing aids listed in GB 2760-9; table salt which is limited to 2% admitted by FDA. According to EEC’s stipulation, it is used for salt, sugar, candy, rice and gum confection; for organic chlorine residue analysis; for polyether adsorbent, with the role of adsorption and decolorization; for column chromatography, pesticide analysis.
Toxicity
ADI values are not subject to special provisions (FAO/WHO, 2001).
GRAS (FDA, § 182.2437, 2000).
Maximal level FAO/WHO (1984, g/kg): powdered dairy products (milk powder, cream powder, high fat milk powder, semi-cream powder) 10 (alone or in combination with other anti-agent, only for vending machines); powdered sugar for coating and glucose powder 15, but no starch included.
Description
Magnesium silicate is very important in the earth
sciences because it is the material that makes up most
of the volume of the Earth. Magnesium silicate can be
prepared by calcining the oxide with silica, SiO2, at an
elevated temperature.
Chemical Properties
white to off-white fine powder
Chemical Properties
A synthetic, usually amorphous form of magnesium silicate in
which the molar ratio of silicon dioxide to magnesium oxide is
approximately 2.2 to 3.3. It occurs as a very fine, white, odorless,
tasteless powder, free from grittiness. It is insoluble in water and
in alcohol, but is readily decomposed by mineral acids. The pH
of a 1 in 10 slurry is between 7.0 and 10.8.
Chemical Properties
Magnesium silicate occurs as an odorless and tasteless, fine, whitecolored
powder that is free from grittiness.
Uses
Magnesium Silicate is a white powder that is insoluble in water and
functions as an anticaking agent. it is used in salt. it is also a process-
ing aid and adsorbent which functions as an anticaking agent and
remover of undesirable proteins during filtration. it is insoluble and
a 10% slurry has a ph of approximately 7.0. it aids in the processing
of beverages, food products, and pharmaceuticals by removing pro-
tein/tannin complex constituents through surface area and adsorp-
tive effects.
Uses
A chromotographic adsorbant.
Uses
Florisil was used as column packing material in column chromatography. Florisil was used as an adsorbent in gas chromatography with electron capture detector (GC/ECD) , capillary column chromatography. and adsorption column chromatography. Florisil was used in clean-up procedures in gas chromatography-tandem mass spectrometry 4 and GC-FID.
Production Methods
Magnesium silicate may be prepared from sodium silicate and
magnesium sulfate. The silicate also occurs in nature as the minerals
meerschaum, parasepiolite, and sepiolite.
General Description
Florisil, adsorbent for the separation of lipids, is a commercially-prepared magnesia silica gel. It has a coarse mesh size which helps in rapid flow rate. Florisil is effective in promoting [1,3]-sigmatropic shift of myceophenolic acid related allyl phenyl ethers. Florisil cartridges are used in atmospheric sampling to assess possible interference from air contaminants.
Hazard
Toxic by inhalation, use in foods restricted
to 2%.
Pharmaceutical Applications
Magnesium silicate is used in oral pharmaceutical formulations and
food products as a glidant and an anticaking agent.
Safety
Magnesium silicate is used in oral pharmaceutical formulations and
is generally regarded as an essentially nontoxic and nonirritant
material.
Orally administered magnesium silicate is neutralized in the
stomach to form magnesium chloride and silicon dioxide; some
magnesium is absorbed. Caution should be used when greater than
50 mEq of magnesium is given daily to persons with impaired renal
function, owing to the risk of hypermagnesemia.
Reported adverse effects include the formation of bladder and
renal calculi following the regular use, for many years, of
magnesium silicate as an antacid.
