What can cause bad results on the TNT830 ULR ammonia method after distillation?

Document ID

Document ID TE156

Published Date

Published Date 25/01/2018
Question
What can cause bad results on the TNT830 ULR ammonia method after distillation?
Summary
Recommendations to improve accuracy after distillation using TNT830 Nitrogen-Ammonia TNTplus
Answer
The TNTplus ULR nitrogen-ammonia TNT830 reagent has unique distillation requirements. The procedure provided below will assist in accurate nitrogen-ammonia results:

Using the  Distillation Apparatus User Manual, follow the procedure specific for Nitrogen-Ammonia Distillation for colorimetric testing.

1. Dilute the boric acid by 50% before adding to the Erlenmeyer flask in step 2.
2. Add 50mL of DI water instead of 25mL of 0.04 N Sulfuric Acid Standard Solution listed in the procedure under Salicylate method, step 6.
3. Measure the pH of the TNT830 vial after the sample added. The reagent vial will measure pH 12, if it does not then raise the pH of the distillate to pH 8 before adding to the TNT830 vial.