LaMotte AMMONIA NITROGEN TEST KIT SL-NH - Manual (Page 2)

PRO CE DURE
1.
Fill test tube (0106) to the 5 mL line with sample water.
2. Add 4 drops of Ammonia Nitrogen Reagent #1 (4797WT). Cap and
mix. Wait 1 minute.
NOTE:
When testing salt (sea) water, increase the amount of
Ammonia Nitrogen Reagent #1 to 8 drops.
3. Add 12 drops of *Ammonia Nitrogen Reagent #2 (4798WT). Cap
and mix. Wait five minutes.
NOTE:
When testing salt water, the reading should be taken after
1 minute to prevent precipitation.
4. Insert the Ammonia Nitrogen Octa-Slide (3438) into the Octa-Slide
Viewer (1100). Insert test tube into the top of the viewer. Match
sample color to a color standard. Record as ppm Ammonia Nitrogen
(NH
3
-N).
To express results as Unionized Ammonia (NH
3
):
ppm Unionized Ammonia (NH
3
) =
ppm Ammonia Nitrogen (NH
3
-N) x 1.2
To express results as Ionized Ammonia (NH
4
+ ):
ppm Ionized Ammonia (NH
4
+ ) =
ppm Ammonia Nitrogen (NH
3
–N) x 1.3
Ammonia in water occurs in two forms: toxic unionized ammonia (NH
3
) and
the relatively non-toxic ionized form, ammonium ion (NH
4
+ ). This test
method measures both forms as ammonia nitrogen (NH
3
–N) to give the total
ammonia-nitrogen concentration in water. The actual proportion of each
compound depends on temperature, salinity, and pH. A greater concentration
of unionized ammonia is present when the pH value and salinity increase.
1.
Consult the table to find the percentage that corresponds to the
temperature, pH, and salinity of the sample.
2. To express the test result as ppm Unionized Ammonia Nitrogen
(NH
3
–N), multiply the total ammonia nitrogen test result by the
percentage from the table.
3. To express the test result as ppm Ionized Ammonia Nitrogen
(NH
4
+ –N), subtract the unionized ammonia-nitrogen determined in
step 2 from the total ammonia nitrogen.