Indian Council of Agricultural Research
(Agricultural Knowledge Management Information System)

ICAR-Central Citrus Research Institute, Post Box No.464, Shankar Nagar P.O., Nagpur-440 010 (
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Instrument Details
Instrument/Facility Name: Nitrogen Analyser
Make                                   : Pelican
Model                                  : KEL PLUS Classic DX VATS (E)
Specification   :Estimation of Ammonical Nitrogen and Protein

Click to ViewKjeldahl method for the determination of organic nitrogen is the world wide standard for the purpose of calculating the nitrogen and protein content in both human and animal feed. Kjeldahl method has been adopted as a Standard method for nitrogen analysis of many non-protein materials, wastewater,, water, fertilizer, fossil fuels etc. The nitrogen analyser finds its utility in the estimation of nitrogen in ammonical form. It is used in the estimation of available nitrogen in soil and total nitrogen.

  Working Principles
Click to ViewEasily utilizable organic nitrogen present in the soil is oxidized by KMNO4 in presence of NaOH. The ammonia released during oxidation is aborbed in Boric Acid to convert ammonia to ammonium borate. The ammonium borated formed is titrated with standard H2SO4. The method kheldahl developed for nitrogen analysis consists of three phases. 1. Digestion 2. Distillation 3. Titration The purpose of digestion step is to break down the intricate structure and chemical bonds to hold chemical substance down to simple chemicals and ionic structure. During digestion step, all the amnio nitrogen is converted to ammonical radial Digestion is the decomposition of nitrogen in organic samples utilizing a concentrated acid solution. This is accomplished by boiling a homogeneous sample in concentrated sulfuric acid. The end result is an ammonium sulfate solution. Organic N + H2SO4 → (NH4)SO4 + H2O + CO2 Digestion is also termed as controlled thermal oxidative degration of sample in concentrated sulphuric acid in presence of potassium sulphate as a catalyst. The presence of potassium sulphate raises the boiling point of the sulfuric acid mixture and shortens the digestion time. The catalyst takes the reaction to completion. The digestion time is less than an hour. Distillation Distillation involves the separation and isolation of the nitrogen from digestion tube. This is done by raising pH with NaOH and by doing this the ammonical radical is converted to ammonia. On heating the ammonia is distilled out and collected in 4% boric acid as a Trapping medium Distillation is adding excess base to the acid digestion mixture to convert NH4 + to NH3, followed by boiling and condensation of the NH3 gas in a receiving solution. (NH4)2SO4 + 2NaOH 2NH3 + Na2SO4 + 2H2O Titration The determination of amount of nitrogen in the condensate flask is done by titrating with standard solution of 0.1 N HCl in presence of mixed indicator NH3 +H3BO3 NH4 H2BO3 +H2O (color change occurs ) (Red color) (Green color complex ) Ammonium-borate complex titrates with HCl and using Tashiro’s indicator to quantify the amount of ammonia in the receiving solution. NH4 H2BO3 + HCl NH4Cl + H3BO3 (Green color complex) (Red color)

  User Instructions
• Organic compounds • Pharmaceuticals • Food and Agriculture Industries • Chemistry and Chemical Engineering • Geological and Environmental samples • Sample must be pure and all contaminants must be removed • For digestion, samples should weigh between 0.300-0.400 g • For Kjeldhal distillation of soil sample, it should not be more than 5 g • No liquid sample

  Contact Us
Contact No. 0712-2500249, 7588006118
Email Id

  Nitrogen Analyser Charges
Procedure Name
National LAB/R&D

Additional Rs 100/-towards postal charges if result are to be posted
The Demand Draft should be in favour of ""
Letter, DD & Samples send to ""