Citric acid is a weak organic acid that has the chemical formula C
6H
8O
7. It occurs naturally in citrus fruits. In biochemistry, it is an intermediate in the citric acid cycle, which occurs in the metabolism of all aerobic organisms.
More than two million tons of citric acid are manufactured every year. It is used widely as an acidifier, as a flavoring and a chelating agent.[9]
A citrate is a derivative of citric acid; that is, the salts, esters, and the polyatomic anion found in solution. An example of the former, a salt is trisodium citrate; an ester is triethyl citrate. When part of a salt, the formula of the citrate anion is written as C
6H
5O3−
7 or C
3H
5O(COO)3−
3
Item | Unit | Standards |
Characters |
--- | White or almost white, crystalline powder, colourless crystals or granules. Odorless, has a strongly acid taste. effloresces in dry air. Very soluble in water, freely soluble in ethanol. |
Identification | --- | Pass Test |
Appearance of solution | --- | Pass Test |
Assay | % | 99.5~ 100.5 |
Water | % | 7.5~ 8.8 |
Readily Carbonisable Substances | --- | Pass Test |
Sulphated Ash (Residue on Ignition) | % | ≤0.05 |
Sulfate | mg/kg | ≤150 |
Oxalate | mg/kg | ≤100 |
Lead | mg/kg | ≤0.5 |
Arsenic | mg/kg | ≤1.0 |
Mercury | mg/kg | ≤1.0 |
Aluminium | mg/kg | ≤0.2 |
Heavy Metals | mg/kg | ≤5.0 |
Bacterial endotoxins | IU/mg | ≤0.5 |
Citric acid is a weak organic acid that has the chemical formula C
6H
8O
7. It occurs naturally in citrus fruits. In biochemistry, it is an intermediate in the citric acid cycle, which occurs in the metabolism of all aerobic organisms.
More than two million tons of citric acid are manufactured every year. It is used widely as an acidifier, as a flavoring and a chelating agent.[9]
A citrate is a derivative of citric acid; that is, the salts, esters, and the polyatomic anion found in solution. An example of the former, a salt is trisodium citrate; an ester is triethyl citrate. When part of a salt, the formula of the citrate anion is written as C
6H
5O3−
7 or C
3H
5O(COO)3−
3
Item | Unit | Standards |
Characters |
--- | White or almost white, crystalline powder, colourless crystals or granules. Odorless, has a strongly acid taste. effloresces in dry air. Very soluble in water, freely soluble in ethanol. |
Identification | --- | Pass Test |
Appearance of solution | --- | Pass Test |
Assay | % | 99.5~ 100.5 |
Water | % | 7.5~ 8.8 |
Readily Carbonisable Substances | --- | Pass Test |
Sulphated Ash (Residue on Ignition) | % | ≤0.05 |
Sulfate | mg/kg | ≤150 |
Oxalate | mg/kg | ≤100 |
Lead | mg/kg | ≤0.5 |
Arsenic | mg/kg | ≤1.0 |
Mercury | mg/kg | ≤1.0 |
Aluminium | mg/kg | ≤0.2 |
Heavy Metals | mg/kg | ≤5.0 |
Bacterial endotoxins | IU/mg | ≤0.5 |