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Principle of chemical reaction

1. Nitrite

 In the acid ethanol system, nitrite ions were converted into NO2 gas and determined at 213.9nm.

    H++NO2-+CH3CH2OH NO2 

2. Ammonia nitrogen

First use the hypobromite oxidation to nitrite, and then according to the method for the determination of nitrite.

    NH3-N+[O] NO2-N;

    H++NO2-+CH3CH2OH NO2

3.Kjeldahl nitrogen

The sample was converted into ammonium hydrogen sulfate solution after the digestion of sulfuric acid and mercury salt at high temperature, and the method was directly determined by ammonia nitrogen determination method.

4. Nitrate

Under heating, titanium trichloride reduction nitrate ion for NO gas, 214.4nm wavelength

      NO3-+TiCl3 NO

5.Total nitrogen

After the sample was digested with alkaline potassium persulfate, all nitrogen compounds were converted into nitrate, and the nitrate was directly determined by the method of determination.

6.Sulfide

The sample after adding acid, sulfide into H2S gas, 202.6nm determination.

      H++[S]2- H2S