How to analyze nitrate toxicity in dairy cows

Nitrate Poisoning

In case of nitrate poisoning, animal becomes blackish because hemoglobin is converted into methaemoglobin which has less oxygen carrying capacity to blood that will lead to absence of bright red colour of blood.

Haemoglobin ==Nitrate==> Methaemoglobin
Blood with Haemoglobin	Blood with Methaemoglobin
More oxygen will be available to blood	Low oxygen will be available to blood
Blood will be bright red in colour	Blood will be blackish/bluish in colour
Oxygen reactive sites will be available	Oxygen reactive sites will be covered

Nitrate strips are used to diagnose the approximate level of nitrates with the range of 10-500ppm.

For liquids: 1ppm = 1mg/ml

For solids: 1ppm = 1mg/g

Nitrate Toxicity estimation

How to Determine Nitrates Level in Plant

We need:
ü Stems and leaves of plant
ü Microwave oven
ü Grinder
ü Nitrate strips

How to Prepare Sample

1) Dry stems and leaves and grind them separately
2) Take three vials
3) Add water in vials:
i. Leaves + Water
ii. Stems + Water
iii. Water only
4) Keep them in microwave oven at moderate heating for some time
5) Dip the strip in solution for 3-5 minutes
6) Remove the strip and shake off excess liquid
7) Read after 30 seconds by comparing strips pads to colour chart

 

Agents/Chemicals present on Nitrate Strip

1. Reducing agents
2. Diazotizers
3. N-(naphthyl) ethylenediamine 

How the Nitrate Strip Works

Nitrates are reduced to nitrites on nitrate strip by different reactions of agents/chemicals discussed above. These reactions are mentioned below:

Nitrates==Reducing Agents==> Nitrites ==Reducing Agents==> NitrousAcid ==Diazotizers==> AromaticAmines ==Coupling with N-(naphthyl) Ethylenediamine==> Red colour compounds

Intensity of colour will be variable depending upon the nitrates’ concentration in the sample.