Title: Preparation and Standardisation of Volumetric Solutions
- Objective: To provide documented procedures, instructions for the Preparation, Standardization and Shelf-life of Volumetric Solutions.
- Scope: This procedure is applicable for Preparation, Standardization and shelf life of Volumetric Solutions in QC Department.
3. Procedure:
- Volumetric solution should be prepared as mentioned in the respective Standard Testing Procedure or official monograph (IP, BP, and USP).
- Volumetric solutions should be prepared by accurately weighing a specified quantity & dissolving it to produce a specific volume.
- Volumetric solutions should be standardized by titration against a Primary Standard or by titration with a Standard Solution that has been recently standardized against a Primary Standard.
- Strength of the volumetric solutions should not deviate more than 10% of the prescribed strength.
- All volumetric solutions should be standardized in triplicate set & % RSD should not be more than 0.20 %.
- All the bottles should be labelled indicating the name, strength of the solution, date of preparation, signature of the person who prepared it, use before date, standardization due on, date of standardization.
- Records shall be maintained for each solution starting with the value determined when the solution was prepared & continuing with the values determined throughout the shelf life of the solutions in respective register.
- Shelf life of this solution is fifteen days to one month based on stability study of respective solution from the date of preparation. Discard the solution after self life or if observed hazy.
- Solutions of limited stability should be prepared on the day of use & discarded on completion of analysis.
- Volumetric Solutions Preparation and Standardization:
List of Volumetric Solutions
| Sr. No. |
Name of Volumetric Solution |
Strength |
|
| 01 |
Ammonium Thiocyanate |
0.1M |
|
| 02 |
Ceric Ammonium Sulphate |
0.1 M |
|
| 03 |
Disodium Edetate |
0.1 M / 0.01 M |
|
| 04 |
Hydrochloric Acid |
1 M |
|
| 05 |
Iodine |
0.05 M |
|
| 06 |
Perchloric Acid |
0.1M |
|
| 07 |
Silver Nitrate |
0.1 M |
|
| 08 |
Sodium Hydroxide |
1 M |
|
| 09 |
Sodium Thiosulphate |
0.1 M |
|
| 10 |
Sulphuric Acid |
0.5 M |
|
| 11 |
Zinc Sulphate |
0.1 M |
|
- 0.1 M Ammonium Thiocyanate:-
- Preparation of Reagents:
- 1 M Silver Nitrate: Dissolve 1.7 g of Silver Nitrate in water and dilute up to 100 ml with water. (Preserve in Amber coloured bottle.)
- Ferric Ammonium Sulphate Solution (8.0 % w/v): Dissolve 8.0 g of Ferric Ammonium Sulphate in water and dilute up to 100 ml with water.
- Procedure for Preparation of 1 M Ammonium Thiocyanate:
Dissolve 7.612 g of Ammonium Thiocyanate in sufficient water and dilute up to 1000 ml with water.
- Procedure for Standardisation of 1 M Ammonium Thiocyanate:-
Pipette 30.0 ml of 0.1M Silver Nitrate into a glass-stoppered flask, dilute with 50 ml of water, add 2 ml of concentrated Nitric acid and 2 ml of Ferric Ammonium Sulphate Solution and titrate with the Ammonium Thiocyanate solution to the first appearance of a red-brown colour.
- Calculation:
Determine the Molarity in triplicate.
Molarity = Volume of Silver Nitrate x Molarity of Silver Nitrate
Volume of Ammonium Thiocyanate
- Acceptance criteria:
The % RSD for triplicate determination of Molarity should not be more than 0.2%.
2. 0.1M Ceric Ammonium Sulphate
-
- Preparation of Reagents:
- Osmic Acid solution (1% w/v): Dissolve 1.0 g of Osmic acid in water and dilute up to 100 ml with water.
- Sodium Hydroxide Solution (8.0 % w/v): Dissolve 8.0 g of Sodium Hydroxide in water and dilute up to 100 ml with water.
- Dilute Sulphuric acid: Dilute 5.7 ml of Sulphuric acid to 100 ml with
- Ferroin Sulphate Solution: Dissolve 0.7 g of Ferrous Sulphate and 1.5 g of 1,10- Phenanthroline Hydrochloride in 70 ml of water and add sufficient water to produce 100 ml.
Complies with the following test
Sensitivity: Add 0.1 ml of the solution and 0.15 ml of Osmic acid solution to 50 ml of 1 M Sulphuric Acid. Add 0.1 ml of 0.1 M Ceric Ammonium Sulphate the colour changes from red to light blue.
- Procedure for Preparation of 1 M Ceric Ammonium Sulphate:
Dissolve 65 g of Ceric Ammonium Sulphate, with the aid of gentle heat, in a mixture of 30 ml of concentrated Sulphuric acid and 500 ml of water. Cool, filter the solution, if turbid and dilute to 1000 ml with purified water.
- Procedure for Standardisation of 1 M Ceric Ammonium Sulphate:
Weigh accurately about 0.2 g of Arsenic trioxide, previously dried at 105°C for 1 hour, and transfer to a 500 ml conical flask. Wash down the inner inner walls of the flask with 25 ml of a 8.0 % w/v solution of Sodium Hydroxide, swirl to dissolve, add 100 ml water and mix. Add 30 ml of Dilute Sulphuric Acid, 0.15 ml of Osmic Acid solution, 0.1 ml of Ferroin Sulphate solution until the pink colour is changed to very pale blue, adding the titrant slowly towards the end point.
1 ml of 0.1 M Ceric Ammonium Sulphate is equivalent to 0.004946 g of As2O3 (of Arsenic trioxide).
- Calculation: Determine the Molarity in triplicate.
Molarity = Weight of Arsenic Trioxide x 0.1
————————————————————————
0.004946 x Burette reading in ml of Cerric Ammonium sulphate
- Acceptance criteria:
The % RSD for triplicate determination of Molarity should not be more than 0.2%.
3. 0.1 M Disodium Edetate and 0.01 M Disodium Edetate:-
-
- Preparation of Reagents:
- Dilute Hydrochloric acid: Dilute 26 ml of Hydrochloric acid to 100 ml with water.
- Bromine Water: Freshly prepared saturated solution obtained by shaking occasionally during 24 hours 3 ml of Bromine with 100 ml of water and allow to separate. Store the solution over an excess of bromine in light resistant container.
- 2 M Sodium Hydroxide Solution: Dissolve 8.0 g of Sodium Hydroxide in sufficient water and dilute to 100 ml with water.
- 10 M Ammonia: Dilute 75 ml of strong ammonia solution to 100 ml with
- Ammonia Buffer pH 10.0: Dissolve 5.4 g of Ammonium Chloride in 20 ml of water, add 35 ml of 10 M Ammonia and dilute to 100 ml with water.
- Mordant Black II (Eriochrome black T) Mixture: A mixture of 1 part of Eriochrome black T and 99 parts of Sodium Chloride.
Complies with following test.
Sensitivity: Dissolve 50 mg in 100 ml water, a brownish violet colour is produced. Add 0.3 ml of 6 M Ammonia; the colour changes to blue. Add 0.1 ml of a 1 per cent w/v solution of Magnesium Sulphate, the colour changes to violet.
- Procedure for Preparation of 1 M Disodium Edetate:
Dissolve 37.2 g of Disodium Edetate in sufficient water to produce 1000 ml.
- Procedure for Preparation of 01 M Disodium Edetate:
Dissolve 3.72 g of Disodium Edetate in sufficient water to produce 1000 ml.
- Procedure for Standardisation of 1 M Disodium Edetate:
Weigh accurately 0.8 g granulated Zinc, dissolve by gentle heating warming in 12 ml of Dilute Hydrochloric Acid and 0.1 ml of Bromine water. Boil to remove excess of Bromine, cool and add sufficient water to produce 200 ml. Pipette 20.0 ml of the resulting solution into a flask and nearly neutralise with 2 M Sodium Hydroxide. Dilute to about 150 ml with water, add sufficient Ammonia Buffer pH 10.0 to dissolve the precipitate and add 5 ml in excess. Add 50 mg of Mordant Black II Mixture and titrate with Disodium Edetate solution until the solution turn green.
1 ml of 0.1 M Disodium Edetate is equivalent to 0.00654 g of Zn (Zinc).
- Procedure for Standardisation of 01 M Disodium Edetate:
Weigh accurately 0.2 g granulated Zinc, dissolve by gentle heating warming in 3 ml of Dilute Hydrochloric Acid and 0.1 ml of Bromine water. Boil to remove excess of Bromine, cool and add sufficient water to produce 500 ml. Pipette 20.0 ml of the resulting solution into a flask and nearly neutralise with 2 M Sodium Hydroxide. Dilute to about 150 ml with water, add sufficient Ammonia Buffer pH 10.0 to dissolve the precipitate and add 5 ml in excess. Add 50 mg of Mordant Black II Mixture and titrate with Disodium Edetate solution until the solution turn green.
- Calculation: (1 M Disodium Edetate)
Determine the Molarity in triplicate.
Molarity = Weight of granulated Zinc x 0.1 x 20
——————————————————————————–
0.00654 x Burette reading in ml of Disodium Edetate x 200
- Calculation: (01 M Disodium Edetate)
Determine the Molarity in triplicate.
Molarity = Weight of granulated Zinc x 0.1 x 20
—————————————————————————–
0.00654 x Burette reading in ml of Disodium Edetate x 500
- Acceptance criteria:
The % RSD for triplicate determination of Molarity should not be more than 0.2%.
4. 1 M Hydrochloric Acid :-
- Preparation of Reagents:
- Methyl Red Solution: Dissolve 50 mg of Methyl Red powder in a mixture of 1.86 ml of 1 M Sodium Hydroxide and 50 ml of ethanol (95%). Shake well to dissolve and add sufficient water to produce 100 ml. (Colour change from Red to Yellow)
Complies with following test.
Sensitivity: A mixture of 0.1 ml of the solution, 100 ml water and 0.05 ml of 0.02 M Hydrochloric acid is red. Not more than 0.1 ml of 0.02 M Sodium Hydroxide is required to change the colour to yellow.
- Procedure for Preparation of 1 M Hydrochloric Acid:
Dilute 85 ml of concentrated Hydrochloric Acid with water to produce 1000 ml.
- Procedure for Standardisation of 1 M Hydrochloric Acid:
Weigh accurately about 1.5 g of anhydrous Sodium Carbonate, previously heated at about 270°C for 1 hour. Dissolve it in 100 ml water and add 0.1 ml of Methyl Red solution. Solution colour is turn from colourless to yellow. Add Hydrochloric acid solution slowly from a burette, with constant stirring until the solution become faintly pink. Heat the solution to boiling, cool and continue the titration. Heat again to boiling and titrate further as necessary until the faint pink colour is no longer affected by continued boiling.
1 ml of 1 M Hydrochloric Acid is equivalent to 0.05299 g of Na2CO3 (Sodium Carbonate).
- Calculation: Determine the Molarity in triplicate.
Molarity = Weight of Anhydrous Sodium Carbonate x 1
——————————————————————————-
0.05299 x Burette reading in ml of 1 M HCL
- Acceptance criteria:
The % RSD for triplicate determination of Molarity should not be more than 0.2%.
5. 0.05 M Iodine:-
-
- Preparation of Reagents:
- Methyl Orange Solution: Dissolve 0.1 g of Methyl Orange 80 ml of water, add sufficient ethanol (95%) to produce 100 ml. (Colour change from Red to Yellow.)
Sensitivity: A mixture of 0.1 ml of the solution and 100 ml of water is yellow. Not more than 0.1 ml of 0.1 M Hydrochloric acid is required to change the colour to Red.
- Starch solution : Triturate (Dissolve) 1 g of soluble Starch with 5 ml water and add under stirring 100 ml of boiling water containing 10 mg of mercuric iodide.
- Dilute Hydrochloric acid: Dilute 26 ml of Hydrochloric acid to 100 ml with water.
- 1 M Sodium Hydroxide: Dissolve 4.0 g of Sodium Hydroxide in sufficient water and dilute to 100 ml with water.
- Procedure for Preparation of 05 M Iodine:
Dissolve about 14 g of Iodine in a solution of 36 g of Potassium Iodide in 100 ml of water, add 3 drops of Hydrochloric acid and dilute with water to 1000 ml.
- Procedure for Standardisation of 05 M Iodine:
Weigh accurately about 0.15 g of Arsenic Trioxide, previously dried at 105° for 1 hour, and dissolve in 20 ml of 1 M Sodium Hydroxide by warming, if necessary. Dilute with 40 ml of water, add 0.1 ml of Methyl Orange solution and add drop wise Dilute Hydrochloric acid until the yellow colour is changed to pink. Add 2 g of Sodium Carbonate, dilute with 50 ml of water and add 3 ml of Starch solution. Titrate with Iodine solution until a permanent blue colour is produced.
1 ml of 0.05 M Iodine is equivalent to 0.004946 g of As2O3 (Arsenic Trioxide).
- Calculation: Determine the Molarity in triplicate.
Molarity = Weight of Arsenic Trioxide x 0.05
—————————————————————
0.004946 x Burette reading in ml of 0.05 M Iodine
- Acceptance criteria:
The % RSD for triplicate determination of Molarity should not be more than 0.2%.
6. 0.1 M Perchloric Acid:-
-
- Preparation of Reagents:
- Crystal Violet solution: Dissolve 5.0 g of Crystal Violet in sufficient anhydrous glacial acetic acid and dilute to 100 ml with anhydrous glacial acetic acid.
[Colour change: Violet (basic) bluish green (neutral) and yellowish green/ Emerald green (acidic)].
Sensitivity: A mixture of 0.1 ml of the solution and 50 ml of Anhydrous Glacial Acetic Acid is bluish purple. Add 0.1 ml of 0.1 M Perchloric Acid: the solution turn bluish green.
- Procedure for Preparation of 1 M Perchloric Acid:
Mix 8.5 ml of Perchloric acid with 500 ml of Anhydrous Glacial Acetic Acid and 25 ml of Acetic Anhydride, cool and add Anhydrous Acetic Acid to produce 1000 ml. Allow the prepared solution stand for 1 day for the excess of Acetic Anhydride to be combined and carryout the determination of water. If the water content exceeds 0.05 %, add more Acetic Anhydride. If the solution contains not titratable water, add sufficient water to obtain a content of water between 0.02 per cent and 0.05 per cent. Allow the solution stand for 1 day and again titrate for water content. Standardize the solution in the following manner.
- Procedure for Standardisation of 1 M Perchloric Acid:-
Weigh accurately about 0.35 g of Potassium Hydrogen Phthalate, previously powdered lightly and dried at 120°C for 2 hours and dissolve it in 50 ml of Anhydrous Glacial Acetic Acid. Add 0.1 ml Crystal Violet solution and titrate with the Perchloric Acid solution until the Violet colour changes to emerald green. Perform a blank determination and make any necessary correction. 1 ml of 1 M Perchloric Acid is equivalent to 0.02042 g of C8H5KO4 (Potassium Hydrogen Phthalate).
- Calculation: Determine the Molarity in triplicate.
Molarity = Weight of Potassium Hydrogen Phthalate x 0.1
——————————————————————
0.02042 x Burette reading in ml of 0.1 M Perchloric Acid
- Acceptance criteria:
The % RSD for triplicate determination of Molarity should not be more than 0.2%.
7. 0.1 M Silver Nitrate:-
-
- Preparation of Reagents:
- Eosin solution: Dissolve 5.0 g of Eosin in sufficient water and dilute to 100 ml with
- Procedure for Preparation of 1 M Silver Nitrate:
Dissolve 17.0 g Silver Nitrate in sufficient water to produce 1000 ml.
- Procedure for Standardisation of 1 M Silver Nitrate:
Weigh accurately about 0.1 g of Sodium Chloride, previously dried at 110°C for 2 hours and dissolve in 5 ml of water. Add 5 ml of Acetic Acid, 50 ml of Methanol and 0.15 ml of Eosin solution. Stir, preferably with magnetic stirrer, and titrate with the 0.1 M Silver Nitrate solution until permanent pink precipitate is produced. 1 ml of 0.1 M Silver Nitrate is equivalent to 0.005844 g of NaCl (Sodium Chloride).
- Calculation: Determine the Molarity in triplicate.
Molarity = Weight of Sodium Chloride x 0.1
——————————————————
0.005844 x Burette reading in ml of 0.1 M Silver Nitrate
- Acceptance criteria:
The % RSD for triplicate determination of Molarity should not be more than 0.2%.
8. 1 M Sodium Hydroxide:-
-
- Preparation of Reagents:
- Phenolphthalein solution: Dissolve 1.0 g of Phenolphthalein in sufficient ethanol (95%) and dilute to 100 ml with ethanol (95%). (Colour change: Colourless to Red.)
Sensitivity: A mixture of 0.1 ml of the solution and 100 ml of water is colourless. Not more than 0.2 ml of 0.02 M Sodium Hydroxide is required to change the colour to pink.
- Procedure for Preparation of 1 M Sodium Hydroxide:
Dissolve 42.0 g of Sodium Hydroxide in sufficient water to produce 1000 ml.
- Procedure for Standardisation of 1 M Sodium Hydroxide:
Weigh accurately about 5.0 g of Potassium Hydrogen Phthalate, previously powdered and dried at 120°C for 2 hours and dissolve in 75 ml of water. Add 0.1 ml Phenolphthalein solution and titrate with the Sodium Hydroxide solution until a permanent pink colour is produced. Each 1 ml of 1 M sodium Hydroxide is equivalent to 0.2042 g of C8H5KO4 (Potassium Hydrogen Phthalate).
- Calculation: Determine the Molarity in triplicate.
Molarity = Weight of Potassium Hydrogen Phthalate x 1.0
———————————————————————-
0.02042 x Burette reading in ml of 1 M Sodium Hydroxide
- Acceptance criteria:
The % RSD for triplicate determination of Molarity should not be more than 0.2%.
9. 0.1 M Sodium Thiosulphate
-
- Preparation of Reagents:
- Starch Solution: Triturate (Dissolve) 1 g of soluble Starch with 5 ml water and add under stirring, 100 ml of boiling water containing 10 mg of mercuric iodide.
- 2 M Hydrochloric Acid: Dilute 17 ml of Conc. Hydrochloric acid to 100 ml with
- Procedure for Preparation of 0.1 M Sodium Thiosulphate:
Dissolve 25.0 g of Sodium Thiosulphate and 0.2 g of Sodium Carbonate in water and dilute to 1000 ml.
- Procedure for Standardisation of 0.1 M Sodium Thiosulphate:
Weigh accurately 0.200 g of Potassium Bromate and dissolve in sufficient water to produce 250.0 ml. To 50.0 ml of this solution add 2 g of Potassium Iodide and 3 ml of 2 M Hydrochloric acid and titrate with the 0.1 M Sodium Thiosulphate solution using Starch solution, added towards the end of the titration, as indicator until the blue colour is discharged. 1 ml of 0.1 M Sodium Thiosulphate is equivalent to 0.002784 g of KBrO3 (Potassium Bromate).
- Calculation: Determine the Molarity in triplicate.
Molarity = Weight of Potassium Bromate x 0.1 x 50
———————————————————–
0.002784 x Burette reading in ml of 0.1 M Sodium Thiosulphate x 250
- Acceptance criteria:
The % RSD for triplicate determination of Molarity should not be more than 0.2%.
10. 0.5 M Sulphuric Acid:-
-
- Preparation of Reagents:
- Methyl Red Solution: Dissolve 50 mg of Methyl Red powder in a mixture of 1.86 ml of 1 M Sodium Hydroxide and 50 ml of ethanol (95%). Shake well to dissolve and add sufficient water to produce 100 ml. (Colour change from Red to Yellow)
Complies with following test.
Sensitivity: A mixture of 0.1 ml of the solution, 100 ml water and 0.05 ml of 0.02 M Hydrochloric acid is red. Not more than 0.1 ml of 0.02 M Sodium Hydroxide is required to change the colour to yellow.
- Procedure for Preparation of 0.5 M Sulphuric Acid:
Add slowly, with stirring, 28 ml of Sulphuric Acid to 1000 ml of water, allow to cool 25° and standardise the solution in the following manner.
- Procedure for Standardisation of 0.5 M Sulphuric Acid:
Weigh accurately about 1.5 g of anhydrous Sodium Carbonate, previously heated at about 270°C for 1 hour. Dissolve it in 100 ml water and add 0.1 ml of Methyl Red solution. Solution colour is turn from colourless to yellow. Add Hydrochloric acid solution slowly from a burette, with constant stirring until the solution become faintly pink. Heat the solution to boiling, cool and continue the titration. Heat again to boiling and titrate further as necessary until the faint pink colour is no longer affected by continued boiling.
1 ml of 0.5 M Sulphuric Acid is equivalent to 0.05299 g of Na2CO3 (Sodium Carbonate).
- Calculation: Determine the Molarity in triplicate.
Molarity = Weight of Anhydrous Sodium Carbonate x 1
—————————————————————-
0.05299 x Burette reading in ml of 0.5 M Sulphuric Acid
- Acceptance criteria:
The % RSD for triplicate determination of Molarity should not be more than 0.2%.
11. 0.1 M Zinc Sulphate :-
-
- Preparation of Reagents:
- 2 M Acetic acid: Dilute 11.4 ml of Glacial Acetic Acid to 100 ml with water.
- Procedure for Preparation of 0.1 M Zinc Sulphate:
Dissolve 29.0 g of Zinc Sulphate in sufficient water and dilute to 1000 ml with water.
- Procedure for Standardisation of 0.1 M Zinc Sulphate:-
Take 20.0 ml of 0.1 M Zinc Sulphate solution into a 500 ml conical flask, add 5 ml of 2 M Acetic acid and dilute to 200 ml with water. Add about 50 mg of Xylenol Orange Mixture and Hexamethylenetetramine until the solution becomes violet-pink. Add 2 g of Hexamethylenetetramine in excess. Titrate with 0.1 M Disodium Edetate until the violet-pink colour changes to yellow.
1 ml of 0.1 M Disodium Edetate is equivalent to 0.02875 g of ZnSO4,7H2O (Zinc Sulphate).
- Calculation: Determine the Molarity in triplicate.
Molarity = Burette reading in ml of Disodium Edetate x Molarity of Disodium Edetate
————————————————————–
Volume of 0.1 M Zinc Sulphate
- Acceptance criteria:
The % RSD for triplicate determination of Molarity should not be more than 0.2%.
“End of Document”
