LaMotte Nitrate-Nitrogen Low Range Enzyme Kit - Manual (Page 4)

Pro ce dure
Low Range (0.00 – 0.20 ppm NO
3
_N)
1. Firmly tap the capped Enzyme Vial (8136) three times on a hard surface.
This will ensure that reagents are at the bottom of the vial.
2. Use the 1 mL pipet (0354) to add 2 mL of Nitrate Buffer (8139).
3. Use a plain pipet (0352) to add sample water until the vial is filled to the
5 mL line.
4. Cap the vial and mix by inverting gently 3 times. Repeat the mixing
procedure at 5 minutes, 10 minutes and 15 minutes. Total reaction time
is 15 minutes.
5. Add 5 drops Hydrochloric Acid, 1N (6130). Cap and mix.
6. Add 1 Nitrate Color Tablet (8140A). Cap the vial and mix by gently
inverting until the tablet disintegrates.
7. Wait 5 minutes.
8. Remove the cap. Place the vial on the white area of the Nitrate-N Low
Range Color Chart (8137LR-CC). Looking down through the tube,
compare the color of the solution to the color chart.
9. Record the result as ppm Nitrate-N (NO
3
_N). To convert the result to
Nitrate (NO
3
) multiply by 4.4.
NOTE: Salinity will reduce the enzyme effectiveness and result in a decrease of
color development.
NOTE:
For the most accurate results use laboratory-grade pipets for measuring
sample water and reagents.