Citric Acid Anhydrous



Description Colorless crystals or white powder, slightly hygroscopic in moist dry air. White or almost white, crystalline powder, colorless crystals or granules White Powder
Solubility Very soluble in water, freely soluble in ethanol (96 %).
Clarity of Solution The Test solution shows the same clarity as that of water.
Appearance of solution (color)


20 % w/v.  solution is clear and not more intensely colored than reference solution  YS7,BYS7 OR GYS7. 20 % w/v solution is clear and color less or not more intensely colored than reference solution Y7, BY7 and GY7. The test solution is not more intensely colored than standard solution A,B, or C, or Water.

(A) Reaction

(B)) By IR Absorption

(C) Reaction

(D) Reaction

(E) Test of water

A.   A 10 % w/v solution is strongly acidic.

B.   Reactions of citrates



A.   10 % w/v solution is strongly acidic

B.   Must comply with the Citric acid                   anhydrous CRS.

C.   A red color develops

D.   White precipitate is produced

E.   Complies with the test of water.


A.   By IR Spectrum


Arsenic NMT 1ppm.
Bacterial end toxins The level of bacterial endotoxins is such that the requirement in the relevant dosage form monograph(S)in which citric acid monohydrate is used can be met.
Sterility Meets the requirements for sterility.
Barium Any opalescence in the solution is not more intense than that in a mixture of 5 ml of solution and 5 ml of distilled water.
Calcium    NMT  200  ppm
Heavy metals           NMT 10 ppm   NMT 10 ppm
Iron          NMT 50 ppm
Readily carbonisable substance Any color produced is not more than intense than that of the a mixture of 1.0 ml of CCS and 9.0 ml of FCS. The solution is not more intensely colored than a mixture of 1 ml of red primary solution and  9 ml of yellow primary solution. The color of acid is not darker than that of a similar volume of matching fluid K
Sulphates  NMT  150 ppm NMT  150 ppm NMT  150 ppm
Oxalic acid    Any pink color is produced is not more instance than that produced by carrying out the test using 0.2 mg of oxalic acid dissolve in 4 ml of water.  . NMT  360  ppm NMT  360  ppm
Limit of Aluminium NMT 0.2 PPM The fluorescencence of the test solution does not exceed that of the standard solution (0.2 µg/g)
Residual Solvents Meets the requirements
Organic Volatile impurities Meets the requirements
Chlorides NMT  50 ppm
Water by KF NMT  1.0 % NMT  1.0 % NMT  1.0 %
Sulphated ash   NMT 0.1 % NMT 0.1 % NMT 0.1 % (residue on ignition)
Assay          99.0 % to 101.0 % 99.5  % – 100.5 % 99.5  % – 100.5 %