We supple citric acid monohydrate. The specification of citric acid monohydrate is give below :

Shape & State : Colorless Crystals
Solubility : In accord with Test
Identification Test : In accord with Test
Transparency & Color : In accord with Test
Barium : Pass the Test
Calcium : Pass the Test
Heavy Metal : < 5 ppm (as Pb)
Iron : < 10 ppm
Chloride : < 50 ppm (as CL)
Oxalate : < 100 ppm
Sulphate : Pass the Test
Readily Carbureted Substance : Less than standard
Sulphated Ash : 0.02%
Assay : 99.78%
Moisture : 8.53 %
Pb : < 1 ppm
Al : < 0.2ppm
Bacteria endotoxic : <0.5 iu/mg