BUFFER SOLUTIONS, used of buffer solution, Prepare a Buffer Solution

BUFFER SOLUTIONS

Commonly used of buffer solution

Preparation a Buffer Solution

 

introduction of  buffer solution

A buffer solution is that which tends to resist changes in pH on the addition of small quantities of acid or alkali. Buffer solutions are made up of a weak acid and a salt of a strong base; or a weak base and a salt of a strong acid. Buffers vary in their buffering capacities. Using various proportions of the constituents in a buffer system, solutions of different pH can be prepared (Appendix D).

Buffers are useful in Clinical Chemistry where it is essential to carefully control pH. For example, when performing estimation of enzyme activity.

The commonly used buffer systems include

(a) Acetate buffer: Acetic acid and sodium acetate

(b) Phosphate buffer: Potassium dihydrogen orthophosphate (KH,PO) and disodium hydrogen orthophosphate (Na HPO.)

(c) Barbitone (Veronal) buffer: Sodium diethyl barbiturate and hydrochloric acid (d) Citrate buffer: Citric acid and sodium citrate.

(e) Tris buffer: Tris amino methane and hydrochloric acid.

How to Prepare a Buffer Solution

1. Weigh out accurately required amount of solid (solute).

2. Place on a magnetic stirring box and dissolve solid in distilled water (solvent).

3. Put pH electrode into the solution.

4. Using appropriate acid or alkali, adjust pH to give the required pH value.

5. Remove electrode and rinse with distilled water.

6. Place electrode in buffer of pH 7.0.

7. Switch the pH meter to stand by.