Page 91 - Feed Lab

Suguna Management System Ver 1.0 / SOP / FQL / P2 - 16 Page 1 of 1

16. Estimation of Non Protein Nitrogen

FTitrate with standard Hydrochloric acid (0.05N)
PRINCIPLE
solution. Note the reading as volume (M1). Run the
It is based on the similar principle of estimation of blank. Note the reading as volume (M2).
protein nitrogen. The NPN compound being soluble in (Picture - 4)
water, the distillate is trapped in known volume of
standard Hydrochloric acid solution. Note:
If having Macro/ Kjeltech distillation unit, 5 gm sample + 150
ml of boiled distilled water and stir well and filter and cool it.
REAGENTS
Finally take whole of solution with 5 gm of MgO and conduct
F 40% Sodium hydroxide solution and Magnesium CP estimation with sufficient volume of 40% alkali solution.
Oxide
F Standard Hydrochloric acid -0.05N

F Boric Acid solution - 4% (40gm Boric acid+10ml
bromo cresol green indicator solution + 7ml Methyl
red indicator solution-for 1lit dis.water- (as same
like protein analysis)

PROCEDURE
Picture - 1 Picture - 2
FTake 5gm of sample in to 250ml Glass beaker. Add
75ml of boiled distilled water. (Picture - 1)

FStir well and filter the solution to SMF. After Cooling
Make up to 100ml with using distilled water.
(Picture - 2)

FTake 10ml aliquot and add 5gm of MgO, then add
10-12 ml 40% NaOH then run the distillation and
collect the distillate in 4% Boric acid solution Picture - 3 Picture - 4
(receiver). (Picture - 3)
Where, N - Normality of Hcl.
M1 - ml of Hcl required in titration for sample.
CALCULATION
1.401 x N x (M1-M2) M2 - ml of Hcl required in titration of blank.
% of NPN = -----------------------------
W W - Weight of the sample (gram).

Prepared by : Approved by :
79 Director - Technical