Sodium Citrate
;)
1,2,3-Propanetricarboxylic acid,2-hydroxy-,trisodium salt.
Trisodium citrate (anhydrous) [68-04-2].
Trisodium citrate dihydrate 294.10 [6132-04-3].
»Sodium Citrate is anhydrous or contains two molecules of water of hydration.It contains not less than 99.0percent and not more than 100.5percent of C6H5Na3O7,calculated on the anhydrous basis.
Packaging and storage—
Preserve in tight containers.
Labeling—
Label it to indicate whether it is anhydrous or hydrous.
Identification—
A:
Asolution (1in 20)responds to the tests for Sodium á191ñand for Citrate á191ñ.
B:
Upon ignition,it yields an alkaline residue which effervesces when treated with 3Nhydrochloric acid.
Alkalinity—
Asolution of 1.0g in 20mLof water is alkaline to litmus paper,but after the addition of 0.20mLof 0.10Nsulfuric acid no pink color is produced by 1drop of phenolphthalein TS.
Water,Method IIIá921ñ—
Dry it at 180
for 18hours:the anhydrous form loses not more than 1.0%,and the hydrous form between 10.0%and 13.0%,of its weight.
for 18hours:the anhydrous form loses not more than 1.0%,and the hydrous form between 10.0%and 13.0%,of its weight.
Tartrate—
To a solution of 1g in 2mLof water add 1mLof potassium acetate TSand 1mLof 6Nacetic acid.Rub the wall of the tube with a glass rod:no crystalline precipitate is formed.
Heavy metals á231ñ—
Dissolve a portion equivalent to 4.4g of anhydrous sodium citrate in enough water to make 50mLof stock solution.Transfer 12mLof this stock solution to a 50-mLcolor-comparison tube (Test Preparation).Transfer 11mLof the stock solution to a second 50-mLcolor-comparison tube containing 1.0mLof Standard Lead Solution(Monitor Preparation).Transfer 1.0mLof Standard Lead Solutionand 11mLof water to a third 50-mLcolor-comparison tube (Standard Preparation).Proceed as directed for Procedure,omitting the dilution to 50mL:the limit is 0.001%.
Assay—
Transfer about 350mg of Sodium Citrate,previously dried at 180for 18hours and accurately weighed,to a 250-mLbeaker.Add 100mLof glacial acetic acid,stir until completely dissolved,and titrate with 0.1Nperchloric acid VS,determining the endpoint potentiometrically.Perform a blank determination,and make any necessary correction.Each mLof 0.1Nperchloric acid is equivalent to 8.602mg of C6H5Na3O7.
for 18hours and accurately weighed,to a 250-mLbeaker.Add 100mLof glacial acetic acid,stir until completely dissolved,and titrate with 0.1Nperchloric acid VS,determining the endpoint potentiometrically.Perform a blank determination,and make any necessary correction.Each mLof 0.1Nperchloric acid is equivalent to 8.602mg of C6H5Na3O7.
Auxiliary Information—
Staff Liaison:Andrzej Wilk,Ph.D.,Senior Scientific Associate
Expert Committee:(PA5)Pharmaceutical Analysis 5
USP28–NF23Page 1782
Phone Number:1-301-816-8305