Preparation of Standard for Analysis of Ammonia Using the Phenate
Method.
1. Get some of the 10 ppm ammonium standard
2. Place each of 0, 0.5, 1, 2, 4, and 5 mL of 10 ppm ammonium standard in a 50
mL volumetric flask
3. Add 1 mL phenol solution and mix thoroughly
4. Add 1 mL sodium nitroprusside solution and mix thoroughly
5. Add 2.5 mL oxidizing solution
6. Add distilled water to make the solution up to mark.
7. Cover and shake thoroughly
8. Let color develop for 1 hr
9. Read absorbance at 640 nm.
You will need to calculate the final concentration of your ammonium solutions. Use the
data to make a Beer Lambert plot