Get the latest updates from us for free

Method of Analysis for Sodium Citrate


Procedure for analysis of Sodium Citrate in pharmaceutical quality control laboratory.
1. Description
A white, crystalline powder or white, granular crystals, slightly deliquescent in moist air.

2. Solubility
Freely soluble in water, practically insoluble in alcohol.

3. Identification
Solution S
Dissolve 10.0 g sample in carbon dioxide-free water prepared from distilled water and dilute to 100 ml with the same solvent.
A. Reactions of Citrates
To 1 ml of solution S add 4 ml of water. To this solution add 0.5 ml of sulphuric acid and 1 ml of potassium permanganate solution and warm until the color of the permanganate is discharged. Add 0.5 ml of a 10% w/v solution of sodium nitroprusside in 1M sulphuric acid and 4 g of sulphamic acid and add 13.5M ammonia dropwise until all the sulphamic acid has dissolved. On addition of an excess of 13.5M ammonia, a violet color is produced which changes to violet-blue.
B. Gives the reactions of Sodium Salt
To 1 ml of solution S add 2 ml of a 15% w/v solution of potassium carbonate and heat to boiling; no precipitate is produced. Add 4 ml of freshly prepared potassium antimonate (V) solution and heat to boiling. Allow cooling in ice and if necessary scratching the inside of the tube with a glass rod; a dense, white precipitate is produced.

4 Appearance of Solution
Limit: Solution S is clear and colorless
Clarity of the Solution
Sample Preparation: Solution S
Standard Preparation: Dissolve 1.0 g of hydrazine sulphate in sufficient water to produce 100.0 ml and allow standing for 4 to 6 hours. Add 25.0 ml of this solution to a solution containing 2.5 g of hexamine in 25.0 ml of water mix well and allow standing for 24 hours. To prepare the standard of opalescence, dilute 15.0 ml of the suspension to 1000.0 ml with water.
Into separate matched, flat-bottomed test tubes, 15 to 25 mm in internal diameter and of colorless, transparent, neutral glass, place sufficient of the solution being examined and of the appropriate reference suspension, such that the test tubes are filled to a depth of 40 mm. Five minutes after preparation of the reference suspension, compare the contents of the test tubes against a black background by viewing in diffused daylight down the vertical axes of the tubes.
Color of Solution
Sample Preparation: Solution S
Using identical tubes of colorless, transparent, neutral glass 12 mm in external diameter compare 2.0 ml of the sample, with 2.0 ml of water in another tube. Compare the colors in diffused daylight, viewing horizontally against a white background.

5. Acidity or alkalinity
Limit: Not more than 0.2 ml of 0.1 M hydrochloric acid or 0.1 M sodium hydroxide is required to change the color of the indicator.
Reagent required
Phenolphthalein solution.
0.1M Hydrochloride Acid 
0.1M Sodium Hydroxide
Procedure
To 10 ml of solution S add 0.1 ml of phenolphthalein solution R. Not more than 0.2 ml of 0.1 M hydrochloric acid or 0.1 M sodium hydroxide is required to change the color of the indicator.

6. Readily Carbonized Substances
Limit: The solution is not more intensely colored than reference solution Y2 or GY2.
Procedure
Sample Solution: To 0.20 g of the powdered substance to be examined add 10 ml of sulphuric acid R and heat in a water-bath at 90°C ±1°C for 60 min. Cool rapidly.
Reference Solution Y2: Take 24ml of yellow primary standard solution, 6ml of the red primary solution in a 100 ml volumetric flask and make up the volume with 1% w/v of HCl. Take 75ml of this solution in a 100 ml volumetric flask and make up the volume with 1% w/v of HCl.
Reference Solution GY2: Take 96 ml of yellow primary standard solution, 2 ml of red primary solution, 2 ml blue primary solution in a 100 ml volumetric flask and make up the volume with 1% w/v of HCl. Take 15 ml of this solution in a 100 ml volumetric flask and make up the volume with 1% w/v of HCl.
Using identical tubes of colorless, transparent, neutral glass with a flat base and an internal diameter of 15 to 25 mm compare a 40-mm layer of the liquid being examined with a 40-mm layer of methanol Examine the columns of liquid in diffused daylight by viewing down the vertical axes of the tubes against a white background.

7. Chlorides
Limit: Not more than 50 ppm
Procedure
Sample Solution: Dilute 10 ml of solution S to 15 ml with water.
To 15 ml of sample solution add 1 ml of 2M nitric acid, pour the mixture as a single addition into 1 ml of silver nitrate solution and allow standing for 5 minutes protected from light. When viewed transversely against a black background any opalescence produced is not more intense than that obtained by treating a mixture of 10 ml of chloride standard solution (5 ppm Cl) and 5 ml of water in the same manner.

8. Oxalate
Limit: Not more than 300 ppm.
Procedure
Dissolve 0.50 g sample in 4 ml of water, add 3 ml of hydrochloric acid and 1 g of granulated zinc and heat on a water-bath for 1 min. Allow to stand for 2 min, decant the liquid into a test-tube containing 0.25 ml of a 10 g/l solution of phenylhydrazine hydrochloride and heat to boiling. Cool rapidly, transfer to a graduated cylinder and add an equal volume of hydrochloric acid and 0.25 ml of potassium ferricyanide solution. Shake and allow standing for 30 min. Any pink color in the solution is not more intense than that in a standard prepared at the same time, in the same manner, using 4 ml of a 50 mg/l solution of oxalic acid.

9. Sulphate
Limit: Not more than 150 ppm.
Procedure
Sample Solution: To 10 ml of solution S add 2 ml of hydrochloric acid and dilute to 15 ml with distilled water.
Add 3 ml of a 250 g/l solution of barium chloride to 4.5 ml of sulphate standard solution (10 ppm SO4). Shake and allow standing for 1 min. To 2.5 ml of this solution, add 15 ml of the sample solution and 0.5 ml of acetic acid. Prepare a standard, in the same manner, using 15 ml of sulphate standard solution (10 ppm SO4 ) instead of the solution to be examined.

10. Heavy metals
Limit: Not more than 10 ppm,
Reagent required
Acetate buffer pH 3.5
Thioacetamide reagent
Lead standard solution (1 ppm)
To 12 ml of the solution S add 2 ml of acetate buffer pH 3.5, mix, add to 1.2 ml of Thioacetamide reagent, mix immediately and allow standing for 2 minutes. Any brown color produced is not more intense than that obtained by treating, in the same manner, a mixture of 10 ml of lead standard solution (1 ppm Pb), and 2 ml of the solution being examined. The standard solution exhibits a slightly brown color when compared to a solution prepared by treating, in the same manner, a mixture of 10 ml of water and 2 ml of the solution being examined.

11. Water
Limit: 11.0 to 13.0 %
Procedure
Transfer 35 to 40 ml of methanol to the titration vessel, and titrate with K.F. reagent, standardized earlier, to the electrometric endpoint to consume any moisture that may be present. Quickly and accurately add 300 mg substance, after adding the substance to be examined, stir for 15 min before titrating, and again titrate with the reagent to the electrometric end-point. Calculate the % of water using formula:
Calculation:
                                    V x F x 100            
Water (% w/w) = -----------------         
                                           W
Where,
V= Volume of K.F. reagent consumed (ml)
F= Water equivalence factor of reagent in mg/ml
W= Weight of substances in mg

12. Assay
Limit: Not less than 99.0 % and Not more than 100.5 % on anhydrous basis
Reagent required
Anhydrous glacial acetic acid,
Naphtholbenzene solution
Perchloric acid 0.1M
Procedure
Dissolve 0.150 g in 20 ml of anhydrous acetic acid R, heating to about 50°C. Allow cooling. Using 0.25 ml of naphtholbenzein solution R as an indicator, titrate with 0.1 M perchloric acid until a green color is obtained. 1 ml of 0.1 M perchloric acid is equivalent to 8.602 mg of C6H5Na3O7.
Calculation:

                                                     V x M x F x 100                100                        
 % Assay on dried basis = ----------------------- x -------------------
                                                             0.1 x W             (100 – Water)
Where,    
V= Consumed volume of 0.1 M Perchloric Acid
M= Molarity of 0.1 M Perchloric Acid
F= Factor
W= Weight of substance.

13. Arsenic
Limit: Not more than 2 ppm
Procedure
Dissolve 5 g sample in 50 ml of water and add 15 ml of stannated hydrochloric acid AsT.
Into the bottle or conical flask introduce the test solution; add 5 ml of 1M potassium iodide and 10 g of zinc AsT. Immediately assemble the apparatus and immerse the flask in a water bath at a temperature such that a uniform evolution of gas is maintained. After 40 minutes any stain produced on the mercuric chloride paper is not more intense than that obtained by treating in the same manner 1.0 ml of arsenic standard solution (10 ppm As) diluted to 50 ml with water.

14. Tartrate
Limit: No crystalline precipitate is formed.
Procedure

To a solution of 1 g in 2 ml of water in a test-tube, add 1 ml of a 10% w/v solution of potassium acetate and 1 ml of 6M acetic acid. Scratch the walls of the test-tube with a glass rod; no crystalline precipitate is formed.



Ankur Choudhary is India's first professional pharmaceutical blogger, author and founder of Pharmaceutical Guidelines, a widely-read pharmaceutical blog since 2008. Sign-up for the free email updates for your daily dose of pharmaceutical tips.
.moc.enilediugamrahp@ofni :liamE Need Help: Ask Question

Click Here

No comments:

Post a Comment