Quality Control Method for Calcium Sequesteration Organo Phosphates
Type: This method can be used to keep a check on the quality of various sequestering agents.
Apparatus :
- Analytical Balance
- pH meter
- Burette 25 ml cap
- Volumetric flask, 100 ml cap & 1000 ml cap.
- Beakers 150 ml cap
- Titration flasks 250 ml capacity.
- Measuring cylinder
- Black Tile.
Reagents:
- Calcium Acetate Monohydrate solution: Dissolve 44.1 gram of Calcium Acetate Monohydrate in distilled water and make up the volume to 1 liter in a volumetric flask. 1 ml of this colution corresponds to 24m.grams of Calcium Carbonate.
- Sodium Carbonate 2% solution
- Sodium Hydroxide 1 N solution
- Acetic Acid 0.1N solution.
- Distilled Water
Procedure:
Weigh accurately about 2 grams of the sequestering agent in a 150 ml beaker. Add about 50 ml of distilled water and dissolve the material. Adjust the pH to 8 with Sodium Hydroxide and Acetic Acid. Add 10ml of 2% Sodium Carbonate by means of a measuring cylinder. Adjust the pH to 11. with Sodium Hydroxide / Acetic acid. Bring the total volume to 100 ml in a volumetric flask. Pour in to 250 ml titration flask and titrate against calcium acetate monohydrate solution to a distinct and permanent turbidity. Keep the black tile on the table and place the titration flask on it. The black background helps in determining the exact end point. During titration maintain the pH constant at 11, by addition acid or alkali.
Result calculation:
Milligrams of Calcium Sequestered per gram of sample
= (Volumel of calcium Acetate Monohydrate / Weight of the sample in grams)
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