LaMotte NITRATE/NITRITE KIT - Manual (Page 2)

Nitrites can cause serious interference in the Nitrate test. To obtain the actual nitrate-
nitrogen concentration, follow Procedures A & B. Subtract the nitrite reading obtained
in Procedure B (as ppm nitrate-nitrogen) from the nitrate reading obtained in
Procedure A (as nitrate-nitrogen).
The best results are obtained when the sample and reagents are at 23 ±2°C.
PROCEDURE A - NITRATE TEST
1. Fill sample bottle (0688) with sample water.
2. Fill test tube (0106) to the 2.5 mL line with water from the sample bottle.
3. Dilute to the 5.0 mL line with *Mixed Acid Reagent (V-6278). Cap and mix.
Wait two minutes.
4. Use the 0.1 g spoon (0699) to add one level measure (avoid any excess) of
*Nitrate Reducing Reagent (V-6279). Cap and invert the tube 50-60 times in
one minute. Wait 10 minutes.
5. Insert the Nitrate-N Octa-Slide 2 Bar (3109-01)into the Octa-Slide 2 Viewer (1101).
6. Insert the test tube into the Octa-Slide 2 Viewer.
7. Match sample color to a color standard. Record as ppm Nitrate-Nitrogen.
8. To convert to ppm Nitrate (NO
3
), multiply the test result by 4.4.
NOTE: To obtain the actual nitrate concentration, follow with Procedure B
and subtract the nitrite reading from the reading obtained in the nitrate test.
NOTE: Thoroughly clean and rinse test tubes after each use.
PROCEDURE B - NITRITE TEST
1. Fill the sample bottle (0688) with sample water.
2. Fill test tube (0106) the 2.5 mL line with water from the sample bottle.
3. Dilute to the 5.0 mL line with *Mixed Acid Reagent (V-6278). Cap and mix.
4. Use the 0.1 g spoon (0699)to add one level measure (avoid any excess) of *Color
Developing Reagent (V-6281). Cap and invert the tube 50-60 times in one minute.
Wait 10 minutes.
5. Insert the Nitrate-N Octa-Slide 2 Bar (3109-01)into the Octa-Slide 2 Viewer (1101).
6. Insert the test tube into the Octa-Slide 2 Viewer.
7. Match sample color to a color standard. Record as ppm Nitrite as Nitrate-Nitrogen.
8. Use the following table to convert reading to Nitrite-Nitrogen. Record as ppm
Nitrite-Nitrogen.
Comparator Reading Divide By
0.5 or less 3.5
0.5-1.5 4.6
over 2.0 5.8
NOTE: If the nitrate-nitrogen reading is higher than 10.0 the sample can be
diluted 1:1 with nitrate and nitrite free water, the test run and the resultant value
obtained multiplied by 2.
NOTE: Thoroughly clean and rinse test tubes after each use.
LaMOTTE COMPANY
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PO Box 329 • Chestertown • Maryland • 21620 • USA
800-344-3100 • 410-778-3100 (Outside U.S.A.) • Fax 410-778-6394
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