Citrate Buffer (2 M)

• Citric Acid 1-Hydrate, HOC(COOH)(CH2COOH)2•H2O

• Sodium Citrate 2-Hydrate,
NaOC(COOH)(CH2COONa)2•2H2O

Warning
Causes eye burns and skin irritation. Do not get in eyes, on
skin, on clothing. Wear impervious gloves and eye
protection when using.


Preparation
2 M Citrate Buffer

1. Add approximately 600 mL of distilled water to a
   1-litre volumetric flask on a magnetic stirrer.
2. Add and dissolve 210.14 g of citric acid 1-hydrate.
3. Add and dissolve 294.11 g of sodium citrate
   2-hydrate.
4. Dilute to volume with distilled water.
5. The pH of this solution is 3.92 ± 0.03 at 77°F (25°C).
   If not, adjust this solution by adding small amount of
   sodium hydroxide to raise the pH or citric acid to
   lower the pH.