What can cause a sample to form white-yellow particles during a Nessler ammonia test?

Document ID

Document ID TE133

Published Date

Published Date 06/15/2022
Question
What can cause a sample to form white-yellow particles during a Nessler ammonia test?
Summary
Interference to nitrogen-ammonia Nessler reagent causing white-yellow precipitant
Answer
The Nitrogen, Ammonia Nessler Method 8038 has several interferences. The normal color reaction using the Nessler reagent is a yellow color.  Samples with a high hardness concentration can form a white precipitate when the Nessler reagent is added.  This is due to the magnesium contributed by magneium carbonate.  The suggestions below can help to mitigate this interference.

- Dilute the sample to minimize hardness below 500 mg/L (CaCO3).
- Confirm the use of the Mineral Stabilizer Solution during the test method.
- If sample dilution is not possible, add 1-2 drops of Rochelle Salt Solution Product # 172533 to the sample prior to testing. The Rochelle Salt will complex the magnesium in solution.

Reference the Water Analysis Handbook (WAH) Nitrogen, Ammonia-Nessler Method 8038_DOC316.53.01078 for full list of interferences.

Was this answer helpful?

Submitting...
Thank you for your feedback!
There was an error with your submission. Please try again.