A pH buffer is a solution that stabilizes the pH of a solution and is commonly used in laboratory, biological, and chemical research. The following are two common pH buffer formulations:
Acid-base pairing method:
Choose a weak acid and its conjugated base, or choose a weak base and its conjugated acid as a pairing combination.
Determine the desired pH and calculate the desired concentration ratio based on the acid-base dissociation constant (Ka) and the base dissociation constant (Kb).
An appropriate amount of weak acid or base is first dissolved in a solvent, then its conjugated base or conjugated acid is gradually added, and the pH of the solution is determined at the same time until the desired target pH is reached.
Be careful to use appropriate laboratory equipment and personal precautions in accordance with laboratory safe operating procedures.
Mixed acid-base solution method:
Choose an acid and a base and mix them in the appropriate proportions to formulate the buffer.
Calculate the required volume ratio according to the required pH value and the concentration of acid and base.
A certain amount of acid is first added to the container, then an appropriate amount of base is gradually added, and the pH of the solution is determined simultaneously until the desired target pH is reached.
Throughout the preparation process, the pH of the solution should be checked regularly and fine-tuned as needed.
Whichever method is used, the following should be noted:
Formulated with high-purity laboratory reagents and purified water to ensure buffer quality.
Stir carefully during the preparation process to avoid air bubbles and contamination.
The prepared pH buffer should be stored in an appropriate container with its pH value and the date of preparation.
The pH of the solution can be detected and calibrated using a pH meter or indicator paper as desired.
Specific preparation methods and ratios will vary depending on the desired pH and the selected acid-base pairing. It is recommended to refer to the relevant chemical literature, laboratory manuals or consult a chemical expert to ensure the correct preparation of the desired pH buffer.
