Water Quality Monitoring: Ammonia

Ammonia

Nitrogen occurs in nateral waters as nitrate (NO₃), nitrite (NO₂), ammonia (NH₃), and organically bound nitrogen.

As aquatic plants and animals die, bacteria break down large protein molecules containing nitrogen into ammonia. Ammonia is then oxidized by specialized bacteria to form nitrites and nitrates.

Sewage is the main source of ammonia added by humans to rivers. The ammonia arises mostly from the hydrolysis of urea in urine, but additional ammonia is generated by the decomposition of other nitrogenous materials in sewage.

In a flowing stream, the presence of ammonia in high concentrations indicates recent pollution. Sewage may be entering the water somewhere in the vicinity.

Test Equipment

LaMotte Ammonia-Nitrogen Test Kit (Code 3304)
Gloves and goggles
Waste container

Procedure

Ammonia

Put on gloves and goggles. Fill one of the plastic test tubes (0124) to the 5 ml line with sample water from the creek.
Add 10 drops salicylate ammonia #1 (3978). Cap and mix.
Add 7 drops salicylate ammonia #2 (3979). Cap and mix. Wait 1 minute.
Add 7 drops salicylate ammonia #3 (3982). Cap and mix. Wait 20 minutes.
Since low concentrations of ammonia will result in a yellow color and the creek water is often slighly yellow itself, collect approximately 2.5 ml of creek water in the second plastic test tube (0124).
After the 20 minute wait, insert the test tube with the treated sample into the octa-slide viewer (1100). Place the second test tube between the small grooves on the back of the viewer so that creek water is seen through both viewports. Slide the ammonia-nitrogen octa-slide bar (3441) left and right in the viewer. Match sample color to a color standard. Record results as ammonia-nitrogen (NH₃-N).

Clean-up

Pour prepared and untreated water samples into the waste container.
Return all glassware and chemicals to their boxes.
When safe to do so, remove gloves and goggles.