LaMotte Nitrate-Nitrogen Low Range Enzyme Kit - Manual (Page 5)

Pro ce dure
High Range (0.2 – 1.0 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 the 0.5 mL pipet (0353) to add 0.5 mL of the sample water to
the Enzyme vial.
4. Use a plain pipet (0352) to add Deionized Water (5115) until the
vial is filled to the 5 mL line.
5. Cap the vial. Mix by inverting gently 3 times. Repeat the mixing
procedure at 5 minutes, 10 minutes and 15 minutes.The total
reaction time is 15 minutes.
6. Add 5 drops Hydrochloric Acid, 1N (6130). Cap and mix.
7. Add 1 Nitrate Color Tablet (8140A). Cap the vial and mix by gently
inverting until the tablet disintegrates.
8. Wait 5 minutes.
9. Remove the cap. Place the vial on the white area of the Nitrate-N
High Range Color Chart (8137HR-CC). Looking down through the
tube, compare the color of the solution to the color chart.
10. 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 ac cu rate re sults use lab o ra tory-grade pipets for
mea sur ing sam ple wa ter and re agents.