LaMotte SMART Spectro Spectrophotometer - Manual (Page 70)

CALCULATIONS:
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 (NH4):
ppm Ionized Ammonia (NH
4+
) =
ppm Ammonia-Nitrogen (NH
3
–N) x 1.3
NOTES: For the best possible results, a reagent blank should be determined to
account for any contribution to the test result by the reagent system. To determine
the reagent blank, follow the above test procedure to scan a distilled or deionized
water blank. Then follow the above procedure to perform the test on a distilled or
deionized water sample. This test result is the reagent blank. Subtract the reagent
blank from all subsequent test results of unknown samples. It is necessary to
determine the reagent blank only when a new lot number of reagents is obtained.
To determine the percentage of Ammonia-Nitrogen that is unionized and ionized,
consult the Appendix.
SMART Spectro Test Procedures 2.11 AMMONIA-NITROGEN, Low Range
Test P
rocedures