Accurately preparing buffers is a fundamental task in every laboratory. This tool allows you to select from a wide range of common laboratory reagents to calculate the exact mass required for your desired molarity and volume.
How to Use the Buffer Master Tool
The calculator operates in three modes. Select your mode using the buttons at the top.
1. Preparation from Solid (Powder)
For single-component buffers like HEPES, Tris, or MOPS. Also supports Custom buffers — enter the MW and pKa manually.
- Select Reagent: Choose a powder from the list or select “Custom” to enter MW and pKa.
- Set Target Molarity and Final Volume.
- Result: Exact mass in grams or milligrams.
2. Preparation from Recipe (pH Specific)
For dual-component systems like Phosphate, Citrate, or Acetate.
- Select Recipe, enter Target pH, and the tool interpolates the acid/base amounts.
3. pH Adjustment
Predict how much strong acid (HCl) or base (NaOH) to add to change a buffer solution from its current pH to a target pH using the Henderson-Hasselbalch equation.
- Select Buffer (or use Custom pKa), Buffer Concentration, Buffer Volume, Current pH, Target pH, and Stock Acid/Base Molarity.
- Result: Microliters of HCl or NaOH to add.
Scientific Principles
Molarity and Mass
Mass = Molarity × Volume × Molar Mass
Henderson-Hasselbalch
pH = pKa + log₁₀([A⁻]/[HA])
The pH adjustment mode uses this equation to calculate the change in conjugate base concentration and the corresponding volume of strong acid/base needed.
Recipe Interpolation
For pH-specific recipes, the calculator interpolates between known data points using linear interpolation.
